Court of Justice of the European Communities (including Court of First Instance Decisions)

JUDGMENT OF THE COURT (Grand Chamber)

13 July 2023 (*)

Table of contents

Legal context

Regulation (EC) No 139/2004

Regulation (EC) No 802/2004

The Guidelines on horizontal mergers

Background to the dispute and the decision at issue

The procedure before the General Court and the judgment under appeal

Procedure before the Court

Forms of order sought by the parties

The appeal

The first ground of appeal

Arguments of the parties

Findings of the Court

The second ground of appeal

The first part

– Arguments of the parties

– Findings of the Court

The second part

– Arguments of the parties

– Findings of the Court

The third ground of appeal

The first part

– Arguments of the parties

– Findings of the Court

The second part

– Arguments of the parties

– Findings of the Court

The third part

– Arguments of the parties

– Findings of the Court

The fourth ground of appeal

The first part

– Arguments of the parties

– Findings of the Court

The second part

– Arguments of the parties

– Findings of the Court

The fifth ground of appeal

Arguments of the parties

Findings of the Court

The sixth ground of appeal

Whether the sixth ground of appeal is effective

– Arguments of the parties

– Findings of the Court

The first part

– Arguments of the parties

– Findings of the Court

The second part

– Arguments of the parties

– Findings of the Court

Referral of the case back to the General Court

Costs

(Appeal – Competition – Regulation (EC) No 139/2004 – Control of concentrations of undertakings – Mobile telecommunications services – Decision declaring a concentration incompatible with the internal market – Oligopolistic market – Significant impediment to effective competition – Non-coordinated effects – Standard of proof – European Commission’s margin of discretion with regard to economic matters – Limits of judicial review – Guidelines on horizontal mergers – Factors relevant to demonstrating a significant impediment to effective competition – Concepts of ‘important competitive force’ and ‘close competitors’ – Closeness of competition between the parties to the concentration – Quantitative analysis of the effects of the proposed concentration on prices – Efficiencies – Distortion – Complaint raised by the General Court of the European Union of its own motion – Annulment)

In Case‑376/20 P,

APPEAL under Article 56 of the Statute of the Court of Justice of the European Union, brought on 7 August 2020,

European Commission, represented initially by G. Conte, M. Farley, J. Szczodrowski and C. Urraca Caviedes, and subsequently by F. Castillo de la Torre, G. Conte, M. Farley, J. Szczodrowski and C. Urraca Caviedes, acting as Agents,

appellant,

supported by:

EFTA Surveillance Authority, represented initially by C. Simpson, M. Sánchez Rydelski and C. Zatschler, and subsequently by C. Simpson and M. Sánchez Rydelski, acting as Agents,

intervener in the appeal,

the other parties to the proceedings being:

CK Telecoms UK Investments Ltd, established in London (United Kingdom), represented initially by J. Aitken, K. Asakura, A. Coe, M. Davis, S. Prichard, Solicitors, O.W. Brouwer, advocaat, B. Kennelly, Senior Counsel, A. Müller, advocate, and T. Wessely, Rechtsanwalt, and subsequently by J. Aitken, K. Asakura, A. Coe, M. Davis, Solicitors, O.W. Brouwer, advocaat, B. Kennelly, Senior Counsel, A. Müller, advocate, and T. Wessely, Rechtsanwalt,

applicant at first instance,

United Kingdom of Great Britain and Northern Ireland, represented initially by S. Brandon, and subsequently by F. Shibli, acting as Agents,

EE Ltd, established in Hatfield (United Kingdom),

interveners at first instance,

THE COURT (Grand Chamber),

composed of K. Lenaerts, President, L. Bay Larsen, Vice-President, A. Arabadjiev (Rapporteur), A. Prechal, M. Safjan, P.G. Xuereb, D. Gratsias and M.L. Arastey Sahún, Presidents of Chambers, J.-C. Bonichot, S. Rodin, F. Biltgen, J. Passer and Z. Csehi, Judges

Advocate General: J. Kokott,

Registrar: M. Longar, Administrator,

having regard to the written procedure and further to the hearing on 14 June 2022,

after hearing the Opinion of the Advocate General at the sitting on 20 October 2022,

gives the following

Judgment

1        By its appeal, the European Commission asks the Court of Justice to set aside the judgment of the General Court of the European Union of 28 May 2020, CK Telecoms UK Investments v Commission (T‑399/16, ‘the judgment under appeal’, EU:T:2020:217), by which the General Court annulled Commission Decision C(2016) 2796 final of 11 May 2016 declaring a concentration incompatible with the internal market (Case COMP/M.7612 – Hutchison 3G UK/Telefónica UK) which was published in summary form in the Official Journal of the European Union of 29 September 2016 (OJ 2016 C 357, p. 15; ‘the decision at issue’).

 Legal context

 Regulation (EC) No 139/2004

2        Recitals 5, 6, 24, 25, 28 and 29 of Council Regulation (EC) No 139/2004 of 20 January 2004 on the control of concentrations between undertakings (the EC Merger Regulation) (OJ 2004 L 24, p. 1) state:

‘(5)       … it should be ensured that the process of reorganisation does not result in lasting damage to competition; Community law must therefore include provisions governing those concentrations which may significantly impede effective competition in the common market or in a substantial part of it.

(6)      A specific legal instrument is therefore necessary to permit effective control of all concentrations in terms of their effect on the structure of competition in the Community and to be the only instrument applicable to such concentrations. Regulation (EEC) No 4064/89 [of 21 December 1989 on the control of concentrations between undertakings (OJ 1989 L 395, p. 1)] has allowed a Community policy to develop in this field. In the light of experience, however, that Regulation should now be recast into legislation designed to meet the challenges of a more integrated market and the future enlargement of the European Union. In accordance with the principles of subsidiarity and of proportionality as set out in Article 5 [TEU], this Regulation does not go beyond what is necessary in order to achieve the objective of ensuring that competition in the common market is not distorted, in accordance with the principle of an open market economy with free competition.

…

(24)      In order to ensure a system of undistorted competition in the common market, in furtherance of a policy conducted in accordance with the principle of an open market economy with free competition, this Regulation must permit effective control of all concentrations from the point of view of their effect on competition in the Community. Accordingly, Regulation [No 4064/89] established the principle that a concentration with a Community dimension which creates or strengthens a dominant position as a result of which effective competition in the common market or in a substantial part of it would be significantly impeded should be declared incompatible with the common market.

(25)      In view of the consequences that concentrations in oligopolistic market structures may have, it is all the more necessary to maintain effective competition in such markets. Many oligopolistic markets exhibit a healthy degree of competition. However, under certain circumstances, concentrations involving the elimination of important competitive constraints that the merging parties had exerted upon each other, as well as a reduction of competitive pressure on the remaining competitors, may, even in the absence of a likelihood of coordination between the members of the oligopoly, result in a significant impediment to effective competition. The Community courts have, however, not to date expressly interpreted Regulation [No 4064/89] as requiring concentrations giving rise to such non-coordinated effects to be declared incompatible with the common market. Therefore, in the interests of legal certainty, it should be made clear that this Regulation permits effective control of all such concentrations by providing that any concentration which would significantly impede effective competition, in the common market or in a substantial part of it, should be declared incompatible with the common market. The notion of “significant impediment to effective competition” in Article 2(2) and (3) should be interpreted as extending, beyond the concept of dominance, only to the anti-competitive effects of a concentration resulting from the non-coordinated behaviour of undertakings which would not have a dominant position on the market concerned.

…

(28)      In order to clarify and explain the Commission’s appraisal of concentrations under this Regulation, it is appropriate for the Commission to publish guidance which should provide a sound economic framework for the assessment of concentrations with a view to determining whether or not they may be declared compatible with the common market.

(29)      In order to determine the impact of a concentration on competition in the common market, it is appropriate to take account of any substantiated and likely efficiencies put forward by the undertakings concerned. It is possible that the efficiencies brought about by the concentration counteract the effects on competition, and in particular the potential harm to consumers, that it might otherwise have and that, as a consequence, the concentration would not significantly impede effective competition, in the common market or in a substantial part of it, in particular as a result of the creation or strengthening of a dominant position. The Commission should publish guidance on the conditions under which it may take efficiencies into account in the assessment of a concentration.’

3        Article 2 of that regulation, entitled ‘Appraisal of concentrations’, provides:

‘1.      Concentrations within the scope of this Regulation shall be appraised in accordance with the objectives of this Regulation and the following provisions with a view to establishing whether or not they are compatible with the common market.

In making this appraisal, the Commission shall take into account in particular:

(a)      the need to maintain and develop effective competition within the common market in view of, among other things, the structure of all the markets concerned and the actual or potential competition from undertakings located either within or outwith the Community;

(b)      the market position of the undertakings concerned and their economic and financial power, the alternatives available to suppliers and users, their access to supplies or markets, any legal or other barriers to entry, supply and demand trends for the relevant goods and services, the interests of the intermediate and ultimate consumers, and the development of technical and economic progress provided that it is to consumers’ advantage and does not form an obstacle to competition.

2.      A concentration which would not significantly impede effective competition in the common market or in a substantial part of it, in particular as a result of the creation or strengthening of a dominant position, shall be declared compatible with the common market.

3.      A concentration which would significantly impede effective competition in the common market or in a substantial part of it, in particular as a result of the creation or strengthening of a dominant position, shall be declared incompatible with the common market.

4.      To the extent that the creation of a joint venture constituting a concentration pursuant to Article 3 has as its object or effect the coordination of the competitive behaviour of undertakings that remain independent, such coordination shall be appraised in accordance with the criteria of Article [101](1) and (3) [TFEU], with a view to establishing whether or not the operation is compatible with the common market.

5.      In making this appraisal, the Commission shall take into account in particular:

–      whether two or more parent companies retain, to a significant extent, activities in the same market as the joint venture or in a market which is downstream or upstream from that of the joint venture or in a neighbouring market closely related to this market,

–      whether the coordination which is the direct consequence of the creation of the joint venture affords the undertakings concerned the possibility of eliminating competition in respect of a substantial part of the products or services in question.’

4        Article 3 of that regulation, entitled ‘Definition of concentration’, states in paragraph 1(b) thereof:

A concentration shall be deemed to arise where a change of control on a lasting basis results from:

…

(b)      the acquisition, by one or more persons already controlling at least one undertaking, or by one or more undertakings, whether by purchase of securities or assets, by contract or by any other means, of direct or indirect control of the whole or parts of one or more other undertakings.’

5        Article 4 of that regulation, entitled ‘Prior notification of concentrations and pre-notification referral at the request of the notifying parties’, provides, in the first subparagraph of paragraph 1 thereof:

‘Concentrations with a Community dimension defined in this Regulation shall be notified to the Commission prior to their implementation and following the conclusion of the agreement, the announcement of the public bid, or the acquisition of a controlling interest.’

6        Article 6 of Regulation No 139/2004, entitled ‘Examination of the notification and initiation of proceedings’, provides, in paragraphs 1 and 2 thereof:

‘1.      The Commission shall examine the notification as soon as it is received.

(a)      Where it concludes that the concentration notified does not fall within the scope of this Regulation, it shall record that finding by means of a decision.

(b)      Where it finds that the concentration notified, although falling within the scope of this Regulation, does not raise serious doubts as to its compatibility with the common market, it shall decide not to oppose it and shall declare that it is compatible with the common market.

A decision declaring a concentration compatible shall be deemed to cover restrictions directly related and necessary to the implementation of the concentration.

(c)      Without prejudice to paragraph 2, where the Commission finds that the concentration notified falls within the scope of this Regulation and raises serious doubts as to its compatibility with the common market, it shall decide to initiate proceedings. Without prejudice to Article 9, such proceedings shall be closed by means of a decision as provided for in Article 8(1) to (4), unless the undertakings concerned have demonstrated to the satisfaction of the Commission that they have abandoned the concentration.

2.      Where the Commission finds that, following modification by the undertakings concerned, a notified concentration no longer raises serious doubts within the meaning of paragraph 1(c), it shall declare the concentration compatible with the common market pursuant to paragraph 1(b).

The Commission may attach to its decision under paragraph 1(b) conditions and obligations intended to ensure that the undertakings concerned comply with the commitments they have entered into vis-à-vis the Commission with a view to rendering the concentration compatible with the common market.’

7        Article 7 of that regulation, entitled ‘Suspension of concentrations’, states in paragraph 1 thereof:

‘A concentration with a Community dimension … shall not be implemented either before its notification or until it has been declared compatible with the common market pursuant to a decision under Articles 6(1)(b), 8(1) or 8(2), or on the basis of a presumption according to Article 10(6).’

8        Article 8 of that regulation, entitled ‘Powers of decision of the Commission’, provides in paragraphs 1 to 3 thereof:

‘1.      Where the Commission finds that a notified concentration fulfils the criterion laid down in Article 2(2) and, in the cases referred to in Article 2(4), the criteria laid down in Article [101](3) [TFEU], it shall issue a decision declaring the concentration compatible with the common market.

A decision declaring a concentration compatible shall be deemed to cover restrictions directly related and necessary to the implementation of the concentration.

2.      Where the Commission finds that, following modification by the undertakings concerned, a notified concentration fulfils the criterion laid down in Article 2(2) and, in the cases referred to in Article 2(4), the criteria laid down in Article [101](3) [TFEU], it shall issue a decision declaring the concentration compatible with the common market.

The Commission may attach to its decision conditions and obligations intended to ensure that the undertakings concerned comply with the commitments they have entered into vis-à-vis the Commission with a view to rendering the concentration compatible with the common market.

A decision declaring a concentration compatible shall be deemed to cover restrictions directly related and necessary to the implementation of the concentration.

3.      Where the Commission finds that a concentration fulfils the criterion defined in Article 2(3) or, in the cases referred to in Article 2(4), does not fulfil the criteria laid down in Article [101](3) [TFEU], it shall issue a decision declaring that the concentration is incompatible with the common market.’

9        Article 10 of that regulation, entitled ‘Time limits for initiating proceedings and for decisions’, provides in paragraph 6 thereof:

‘Where the Commission has not taken a decision in accordance with Article 6(1)(b), (c), 8(1), (2) or (3) within the time limits set in paragraphs 1 and 3 respectively, the concentration shall be deemed to have been declared compatible with the common market …’

10      Article 21 of Regulation No 139/2004, entitled ‘Application of the Regulation and jurisdiction’, provides in paragraph 2 thereof:

‘Subject to review by the Court of Justice, the Commission shall have sole jurisdiction to take the decisions provided for in this Regulation.’

 Regulation (EC) No 802/2004

11      Article 3 of Commission Regulation (EC) No 802/2004 of 21 April 2004 implementing Regulation No 139/2004 (OJ 2004 L 133, p. 1, and corrigendum OJ 2004 L 172, p. 9), as amended by Commission Implementing Regulation (EU) No 1269/2013 of 5 December 2013 (OJ 2013 L 336, p. 1) (‘Regulation No 802/2004’), provides that, for the purposes of merger control, notifications are to be submitted in the manner prescribed by Form CO set out in Annex I to that regulation.

12      Section 9 of that Annex I, entitled ‘Efficiencies’, is worded as follows:

‘Should you wish the Commission specifically to consider from the outset … whether efficiency gains generated by the concentration are likely to enhance the ability and incentive of the new entity to act pro-competitively for the benefit of consumers, provide a description of, and supporting documents relating to, each efficiency (including cost savings, new product introductions, and service or product improvements) that the parties anticipate will result from the proposed concentration relating to any relevant product …

For each claimed efficiency, provide:

(i)      a detailed explanation of how the proposed concentration would allow the new entity to achieve the efficiency. Specify the steps that the parties anticipate taking to achieve the efficiency, the risks involved in achieving the efficiency, and the time and costs required to achieve it;

(ii)      where reasonably possible, a quantification of the efficiency and a detailed explanation of how the quantification was calculated. Where relevant, also provide an estimate of the significance of efficiencies related to new product introductions or quality improvements. For efficiencies that involve cost savings, state separately the one-time fixed cost savings, recurring fixed cost savings, and variable cost savings (in EUR per unit and EUR per year);

(iii)      the extent to which customers are likely to benefit from the efficiency and a detailed explanation of how this conclusion is arrived at; and

(iv)      the reason why the party or parties could not achieve the efficiency to a similar extent by means other than through the concentration proposed, and in a manner that is not likely to raise competition concerns.’

 The Guidelines on horizontal mergers

13      The Commission Notice entitled ‘Guidelines on the assessment of horizontal mergers under the Council Regulation on the control of concentrations between undertakings’ (OJ 2004 C 31, p. 5; ‘the Horizontal Merger Guidelines’), in a section concerning non-coordinated effects, states:

‘Non-coordinated effects …

24.      A merger may significantly impede effective competition in a market by removing important competitive constraints on one or more sellers, who consequently have increased market power. The most direct effect of the merger will be the loss of competition between the merging firms. For example, if prior to the merger one of the merging firms had raised its price, it would have lost some sales to the other merging firm. The merger removes this particular constraint. Non-merging firms in the same market can also benefit from the reduction of competitive pressure that results from the merger, since the merging firms’ price increase might switch some demand to the rival firms, which, in turn, may find it profitable to increase their prices … The reduction in these competitive constraints could lead to significant price increases in the relevant market.

25.      Generally, a merger giving rise to such non-coordinated effects would significantly impede effective competition by creating or strengthening the dominant position of a single firm, one which, typically, would have an appreciably larger market share than the next competitor post-merger. Furthermore, mergers in oligopolistic markets … involving the elimination of important competitive constraints that the merging parties previously exerted upon each other together with a reduction of competitive pressure on the remaining competitors may, even where there is little likelihood of coordination between the members of the oligopoly, also result in a significant impediment to competition. The Merger Regulation clarifies that all mergers giving rise to such non-coordinated effects shall also be declared incompatible with the common market …

26.      A number of factors which, taken separately, are not necessarily decisive, may influence whether significant non-coordinated effects are likely to result from a merger. Not all of these factors need to be present for such effects to be likely. Nor should this be considered an exhaustive list.

Merging firms have large market shares

27.      The larger the market share, the more likely a firm is to possess market power. And the larger the addition of market share, the more likely it is that a merger will lead to a significant increase in market power. The larger the increase in the sales base on which to enjoy higher margins after a price increase, the more likely it is that the merging firms will find such a price increase profitable despite the accompanying reduction in output. Although market shares and additions of market share only provide first indications of market power and increases in market power, they are normally important factors in the assessment …

Merging firms are close competitors

28.      Products may be differentiated … within a relevant market such that some products are closer substitutes than others … The higher the degree of substitutability between the merging firms’ products, the more likely it is that the merging firms will raise prices significantly … For example, a merger between two producers offering products which a substantial number of customers regard as their first and second choices could generate a significant price increase. Thus, the fact that rivalry between the parties has been an important source of competition on the market may be a central factor in the analysis … High pre-merger margins … may also make significant price increases more likely. The merging firms’ incentive to raise prices is more likely to be constrained when rival firms produce close substitutes to the products of the merging firms than when they offer less close substitutes … It is therefore less likely that a merger will significantly impede effective competition, in particular through the creation or strengthening of a dominant position, when there is a high degree of substitutability between the products of the merging firms and those supplied by rival producers.

29.      Where data are available, the degree of substitutability may be evaluated through customer preference surveys, analysis of purchasing patterns, estimation of the cross-price elasticities of the products involved … or diversion ratios … In bidding markets, it may be possible to measure whether historically the submitted bids by one of the merging parties have been constrained by the presence of the other merging party …

30.      In some markets, it may be relatively easy and not too costly for active firms to reposition their products or extend their product portfolio. In particular, the Commission examines whether the possibility of repositioning or product line extension by competitors or the merging parties may influence the incentive of the merged entity to raise prices. However, product repositioning or product line extension often entails risks and large sunk costs … and may be less profitable than the current line.

…

Merger eliminates an important competitive force

37.      Some firms have more of an influence on the competitive process than their market shares or similar measures would suggest. A merger involving such a firm may change the competitive dynamics in a significant, anti-competitive way, in particular when the market is already concentrated … For instance, a firm may be a recent entrant that is expected to exert significant competitive pressure in the future on the other firms in the market.

38.      In markets where innovation is an important competitive force, a merger may increase the firms’ ability and incentive to bring new innovations to the market and, thereby, the competitive pressure on rivals to innovate in that market. Alternatively, effective competition may be significantly impeded by a merger between two important innovators, for instance between two companies with “pipeline” products related to a specific product market. Similarly, a firm with a relatively small market share may nevertheless be an important competitive force if it has promising pipeline products …’

 Background to the dispute and the decision at issue

14      The background to the dispute is set out in paragraphs 1 to 25 of the judgment under appeal and may be summarised as follows.

15      On 11 September 2015, the Commission received notification, in accordance with Article 4 of Regulation No 139/2004, of a proposed concentration (‘the proposed concentration’) whereby CK Hutchison Holdings Ltd was to acquire, through the intermediary of its indirect subsidiary Hutchison 3G UK Investments Ltd, which became CK Telecoms UK Investments Ltd (‘CK Telecoms’), in the manner described in Article 3(1)(b) of that regulation, sole control over Telefónica Europe plc (‘O2’).

16      Four mobile network operators were at that time present on the retail market for mobile telecommunications services in the United Kingdom (‘the retail market’): namely EE Ltd, a subsidiary of BT Group plc, acquired by BT Group in 2016 (‘BT/EE’), O2, Vodafone and Hutchison 3G UK Ltd (‘Three’), an indirect subsidiary of CK Hutchison Holdings, whose market shares, in terms of subscribers, were approximately between 30% and 40%, between 20% and 30%, between 10% and 20% and between 10% and 20% respectively. Following the proposed concentration, Three and O2 would account for approximately between 30% and 40% of the retail market and thus was able to become the main player on that market, ahead of the former legacy operator BT/EE and Vodafone.

17      The retail market also included a number of mobile virtual network operators who did not own a mobile network, such as Tesco Mobile – a company owned in equal shares by Tesco and O2 – as well as Virgin Mobile and TalkTalk. Those operators had concluded agreements with mobile network operators so as to have access to their network at wholesale prices. The retail market also included branded resellers and independent retailers, such as Dixons.

18      A characteristic of the retail market was that BT/EE and Three, on the one hand, and Vodafone and O2, on the other, had concluded network-sharing agreements, referred to as MBNL and Beacon respectively, enabling them to share the costs of rolling out their networks while continuing to compete on the retail market.

19      On 2 October 2015, the United Kingdom of Great Britain and Northern Ireland requested, through the intermediary of its national competition authority, the Competition and Markets Authority, that the proposed concentration be referred to it, pursuant to Article 9(2)(a) of Regulation No 139/2004. The United Kingdom submitted that the concentration threatened significantly to impede competition on the retail market and on the market for wholesale access and call origination on public mobile networks in the United Kingdom (‘the wholesale market’). The United Kingdom also maintained that it was best placed to deal with the concentration.

20      That referral request was rejected by Commission Decision C(2015) 8534 final of 4 December 2015 concerning Article 9 of Regulation No 139/2004 in Case M.7612 Hutchison 3G UK/Telefónica UK. In support of that decision, the Commission considered in particular that it was necessary for it to ensure a coherent and consistent approach when assessing mergers in the telecommunications sector in various Member States and it also referred to the considerable expertise it had gained in the assessment of concentrations in the European mobile telecommunications markets.

21      On 30 October 2015, on account of serious doubts as to the compatibility of the proposed concentration with the internal market, the Commission adopted a decision to initiate the procedure under Article 6(1)(c) of Regulation No 139/2004.

22      On 4 February 2016, the Commission issued a Statement of Objections. CK Telecoms submitted its written observations on the Statement of Objections on 26 February 2016.

23      On 2 March 2016, in order to address the competition concerns identified in the Statement of Objections, CK Telecoms submitted a first set of commitments.

24      At CK Telecom’s request, an oral hearing was held on 7 March 2016.

25      On 15 March 2016, CK Telecoms submitted revised commitments.

26      On 17 and 23 March 2016, the Commission sent CK Telecoms letters in which it pointed to additional evidence in its file in support of the preliminary findings of the Statement of Objections. On 29 March and 4 April 2016, CK Telecoms submitted written observations on those letters.

27      On 6 April 2016, CK Telecoms submitted a third set of commitments.

28      On 27 April 2016, the Advisory Committee on Concentrations issued a favourable opinion on the draft of the Commission’s decision.

29      On 11 May 2016, the Commission adopted the decision at issue, which is founded on two relevant markets having been identified: namely the retail market and the wholesale market.

30      The Commission set out three theories of harm, all of which were based on the existence of non-coordinated effects on an oligopolistic market.

31      The first theory of harm relates to the existence of non-coordinated effects on the retail market arising from the elimination of important competitive constraints. In essence, according to the Commission, the sharp reduction in competition which would have resulted from the proposed concentration would probably have led to an increase in prices for mobile telephony services in the United Kingdom and a restriction of choice for consumers.

32      The second theory of harm concerns the existence of non-coordinated effects on the retail market relating to network sharing. According to the Commission, the proposed concentration would be likely to have a negative influence on the quality of services for consumers, hindering the development of mobile network infrastructure in the United Kingdom.

33      The third theory of harm concerns the existence of non-coordinated effects arising from the elimination of important competitive constraints on the wholesale market. On that market, the four mobile network operators provide hosting services to operators which do not own a mobile network which, in turn, offer retail services to subscribers. In particular, the proposed concentration was likely to have significant non-coordinated effects on the wholesale market resulting from a reduction in the number of mobile network operators from four to three, the elimination of Three as an important competitive force, the removal of important competitive constraints which the parties had previously exerted upon each other, and a reduction of competitive pressure on the remaining players.

34      As regards the efficiencies alleged by CK Telecoms, the Commission found that they were neither verifiable nor specific to the concentration, nor likely to benefit consumers.

35      In the final section of the decision at issue, the Commission examined the commitments offered by CK Telecoms. It found, in essence, that the second and third sets of commitments did not eliminate, or at least not completely, all the competition concerns identified.

36      Consequently, the Commission declared the proposed concentration to be incompatible with the internal market.

 The procedure before the General Court and the judgment under appeal

37      By application lodged at the Registry of the General Court on 25 July 2016, CK Telecoms brought an action for annulment of the decision at issue.

38      In support of that action, CK Telecoms relied on five pleas in law.

39      The first and fourth pleas in law related to the first and third theories of harm, concerning the elimination of competition between Three and O2 in the retail market and in the wholesale market respectively. The second plea in law related to the Commission’s assessment of the counterfactual scenario, on which it based its evaluation of the retail and wholesale markets. The third plea in law related to the Commission’s second theory of harm, concerning the retail market, in relation to network sharing, and CK Telecoms’ commitments in relation to network sharing. The fifth plea in law related to the other commitments offered by CK Telecoms.

40      The General Court first of all examined the first, third and fourth pleas in turn and then examined the second and fifth pleas in law.

41      By the judgment under appeal, the General Court, first of all, upheld, in essence, the first part of the first plea in law concerning the intensity of judicial review in respect of concentrations, the legal framework applicable following the adoption of Regulation No 139/2004, the burden of proof and the standard of proof incumbent on the Commission where it has to prove a significant impediment to effective competition, in accordance with Article 2(3) of that regulation. The General Court also upheld the second part of the first plea in law, concerning the classification of Three as an ‘important competitive force’, as well as the third and fifth parts of that plea in law, relating to the assessment of the closeness of competition and to the assessment of the quantitative effects of the proposed concentration on prices respectively. In addition, the General Court upheld CK Telecoms’ argument forming part of the seventh part of the first plea in law, according to which the Commission failed to state in its decision on what basis it concluded that the alleged impediments to competition resulting from the concentration were significant. Next, it upheld the first, third, fourth, fifth and sixth parts of the third plea in law, which alleged errors in connection with the horizontal non-coordinated effects arising from network sharing. Finally, the General Court upheld the first three parts of the fourth plea in law, concerning non-coordinated effects on the wholesale market. Consequently, the General Court annulled the decision at issue.

 Procedure before the Court

42      By document lodged at the Registry of the Court of Justice on 7 August 2020, the Commission brought the present appeal.

43      By a separate document lodged on the same date, the Commission requested the Court of Justice to grant confidential treatment, vis-à-vis EE, being one of the two interveners at first instance, in respect of certain passages of that appeal which contained information constituting business secrets and which corresponded to information for which the General Court had granted confidential treatment. By order of 1 October 2020, Commission v CK Telecoms UK Investments (C‑376/20 P, EU:C:2020:789), the President of the Court of Justice granted that request. Accordingly, only a non-confidential version of that appeal was served on EE.

44      By document lodged at the Court Registry on 20 November 2020, CK Telecoms requested the Court of Justice to grant confidential treatment, vis-à-vis EE, in respect of certain information in its response which constituted business secrets and which, for that reason, ought not be disclosed to its competitor EE, and which corresponded to information for which the General Court had granted confidential treatment vis-à-vis EE. By order of 26 January 2021, Commission v CK Telecoms UK Investments (C‑376/20 P, EU:C:2021:81), the President of the Court granted confidential treatment as regards EE in respect of that pleading, with only a non-confidential version of that submission being served on EE.

45      By a document lodged at the Court Registry on 24 March 2021 on the basis of the third paragraph of Article 40 of the Statute of the Court of Justice of the European Union and Article 130 of the Rules of Procedure of the Court of Justice, applicable to appeal proceedings by virtue of Article 190(1) of those rules, the EFTA Surveillance Authority applied for leave to intervene in the present case in support of the form of order sought by the Commission. By order of 4 June 2021, Commission v CK Telecoms UK Investments (C‑376/20 P, EU:C:2021:488), the President of the Court granted that request, authorising it to submit its observations at the hearing. A copy of all the procedural documents was served on that authority.

46      Following a request from the Commission dated 12 February 2021, the President of the Court granted it leave to lodge a reply.

47      After CK Telecoms lodged its rejoinder, the written part of the procedure in the present case was closed on 19 May 2021.

 Forms of order sought by the parties

48      The Commission requests the Court to:

–        annul the judgment under appeal;

–        refer the case back to the General Court;

–        order CK Telecoms to pay the costs of the present appeal; and

–        reserve the costs of the proceedings at first instance.

49      CK Telecoms contends that the Court should:

–        dismiss the appeal; and

–        order the Commission and the interveners to pay the costs of the proceedings before both the General Court and the Court of Justice.

 The appeal

50      The Commission puts forward six grounds in support of its appeal. The first alleges an error of law in that the General Court applied a stricter standard of proof than that resulting from the case-law of the Court of Justice concerning concentrations. The second ground of appeal alleges a misinterpretation of Article 2(3) of Regulation No 139/2004. The third ground of appeal alleges that the General Court exceeded the limits of judicial review in interpreting the concepts of ‘important competitive force’ and ‘close competitors’, misinterpreted those concepts and distorted both the decision at issue and the Commission’s defence. The fourth ground of appeal alleges distortion of the Commission’s arguments concerning the quantitative analysis of the effects of the proposed concentration on prices and errors of law made by the General Court in its assessment of that analysis. The fifth ground of appeal alleges that the General Court did not assess all the relevant evidence together. The sixth ground of appeal alleges errors concerning network sharing.

 The first ground of appeal

 Arguments of the parties

51      By its first ground of appeal, the Commission submits that, by finding, in paragraph 118 of the judgment under appeal, that it is required to produce sufficient evidence to demonstrate with a strong probability the existence of a significant impediment to effective competition, the General Court applied a particularly high standard of proof, going beyond that resulting from the case-law of the Court of Justice on the control of concentrations, and, in so doing, made an error of law. That error led the General Court to observe, in paragraphs 119, 172, 216, 268, 281 and 396 of the judgment under appeal, that the Commission did not prove to the requisite legal standard that the concentration would result in a significant impediment to effective competition.

52      In that regard, it is apparent from paragraph 52 of the judgment of 10 July 2008, Bertelsmann and Sony Corporation of America v Impala (C‑413/06 P, EU:C:2008:392) that, where it has been notified of a proposed concentration, the Commission is, in principle, required to adopt a position, either in the sense of approving or of prohibiting the concentration, in accordance with its assessment of the economic outcome attributable to the notified concentration which is most likely to ensue.

53      The standard of proof required by the General Court in paragraph 118 of the judgment under appeal in order to establish whether there is a significant impediment to effective competition necessarily means that it has no symmetry compared with the standard of proof which may be inferred from Article 2(2) and (3) of Regulation No 139/2004, since that provision establishes neither that there is a general presumption that a notified concentration is compatible with, or incompatible with the internal market.

54      CK Telecoms contends, in the first place, that the first ground of appeal is ineffective.

55      It is apparent in particular from the judgment under appeal that the Commission made errors of law relating to the interpretation of the concepts of ‘important competitive force’ and ‘close competitors’ at a prior stage of its assessment before the examination of the evidence which led it to find that there was a significant impediment to effective competition. Those errors are therefore not affected by the allegedly erroneous standard of proof required by the General Court.

56      In addition, the Commission has failed to demonstrate that a lower standard of proof than that required by the General Court would have led to a different result.

57      In the second place, CK Telecoms submits that the standard of proof required by the General Court is consistent with the case-law of the Court of Justice.

58      It submits that, in the judgment of 10 July 2008, Bertelsmann and Sony Corporation of America v Impala (C‑413/06 P, EU:C:2008:392), the Court of Justice did not follow the Opinion of Advocate General Kokott and did not adopt the ‘balance of probabilities’ as the standard of proof required in order to establish the existence of a significant impediment to effective competition.

59      In CK Telecoms’ view, such a standard of proof implies that it is sufficient for the Commission to rely on evidence which is not particularly consistent or convincing in order to demonstrate that the existence of a significant impediment to effective competition is more probable than improbable.

60      It is apparent from paragraphs 27, 39, 41 and 45 of the judgment of 15 February 2005, Commission v Tetra Laval (C‑12/03 P, EU:C:2005:87), that, in order to find a significant impediment to effective competition, the evidence must be robust in order to establish convincingly the merits of an argument set out in a merger control decision, which presupposes that the factual accuracy, reliability and consistency of that evidence have been established.

61      CK Telecoms submits that although the Commission must apply the same standard of proof both to authorise and to prohibit a concentration, the fact remains that to require of that institution a higher standard of proof than the mere ‘balance of probabilities’ in order to demonstrate whether there is a significant impediment to effective competition does not undermine the neutrality established in Article 2(2) and (3) of Regulation No 139/2004.

62      In those circumstances, CK Telecoms submits that, by referring, in paragraph 118 of the judgment under appeal, to a reading a contrario of points 209 to 211 of the Opinion of Advocate General Kokott in Bertelsmann and Sony Corporation of America v Impala (C‑413/06 P, EU:C:2007:790), and in finding that the standard of proof applicable to the Commission was stricter than the mere ‘balance of probabilities’, the General Court made no error of law.

 Findings of the Court

63      As regards CK Telecoms’ argument that the first ground of appeal is ineffective, it should be noted that it is apparent, in particular, from paragraphs 119, 172, 216, 281, 282, 372 and 396 of the judgment under appeal that the General Court ruled on whether there was a significant impediment to effective competition, in particular by having recourse to the concepts of ‘important competitive force’ and ‘close competitors’, in the light of the standard of proof set out in paragraph 118 of that judgment. Accordingly, irrespective of whether, as the Commission argues in its third ground of appeal, the interpretation of those concepts is vitiated by errors of law, the Commission may also reasonably criticise the General Court for having required a higher standard of proof than that resulting from the case-law of the Court of Justice concerning concentrations.

64      Furthermore, it is necessary to reject CK Telecoms’ argument that the Commission failed to establish that a standard of proof different from that applied by the General Court would have led to a different result. First, in principle it is for CK Telecoms to demonstrate that the first ground of appeal is ineffective. Second, since, as is apparent from paragraphs 118 and 119 of the judgment under appeal, the requirement for a strong probability of the existence of a significant impediment to effective competition was applied by the General Court to all the evidence which it examined, it cannot be ruled out, a priori, that applying a lower standard of proof could have resulted in the action being dismissed at first instance.

65      It is therefore necessary to (i) reject CK Telecoms’ argument that the first ground of appeal is ineffective and (ii) examine the substance of that ground of appeal.

66      In that regard, it should be recalled that it is apparent, in particular, from recital 5 of Regulation No 139/2004 that that regulation seeks to ensure that the reorganisation of undertakings does not result in lasting damage to competition.

67      It should also be recalled that, first, Article 2(2) of that regulation provides that a concentration which would not significantly impede effective competition is to be declared compatible with the internal market. Second, it follows from Article 2(3) of that regulation that, in the opposite situation, a concentration which would have such an effect is to be declared incompatible with the internal market.

68      The EU legislature therefore provided, in Article 8(1) of Regulation No 139/2004, that, where the Commission finds that a notified concentration fulfils the criterion laid down in Article 2(2) of that regulation, it is to issue a decision declaring that concentration compatible with the internal market. By contrast, as is apparent from Article 8(3) of that regulation, where the Commission finds that a concentration fulfils the criterion defined in Article 2(3) of that regulation, it is to issue a decision declaring that that concentration is incompatible with the internal market.

69      It therefore follows from the wording of both Article 2(2) and (3) of Regulation No 139/2004 and of Article 8(1) and (3) thereof that those provisions are symmetrical as regards the standards of proof imposed on the Commission in order to demonstrate that a notified concentration would or would not significantly impede effective competition and must therefore be declared incompatible or compatible with the internal market.

70      In that regard, it should be noted, in the first place, that there is nothing in those provisions which states that Regulation No 139/2004 imposes different standards of proof in relation to decisions approving a concentration, on the one hand, and decisions prohibiting a concentration, on the other (see, to that effect, judgment of 10 July 2008, Bertelsmann and Sony Corporation of America v Impala, C‑413/06 P, EU:C:2008:392, paragraph 46).

71      In that context, no general presumption that a concentration is compatible with, or incompatible with, the internal market can be inferred from that regulation (see, to that effect, judgment of 10 July 2008, Bertelsmann and Sony Corporation of America v Impala, C‑413/06 P, EU:C:2008:392, paragraph 48).

72      While it is true that Article 10(6) of that regulation provides that a notified concentration is to be deemed compatible with the internal market where the Commission has not taken a decision on the compatibility of that transaction within the prescribed period, the fact remains that that provision, first, is a specific expression of the need for speed which characterises the general scheme of the regulation and, second, constitutes an exception to the general scheme of the regulation, according to which the Commission is to rule expressly on concentrations which are notified to it (see, to that effect, judgment of 10 July 2008, Bertelsmann and Sony Corporation of America v Impala, C‑413/06 P, EU:C:2008:392, paragraph 49).

73      In those circumstances, it must be held that the Commission is not required to comply with a higher standard of proof in relation to decisions prohibiting concentrations than in relation to decisions approving concentrations (see, to that effect, judgment of 10 July 2008, Bertelsmann and Sony Corporation of America v Impala, C‑413/06 P, EU:C:2008:392, paragraph 51).

74      It follows that the requirements concerning the taking of evidence, including the standard of proof, do not vary according to the type of decision adopted by the Commission in merger control.

75      In the second place, it is apparent from the case-law that decisions of the Commission as to the compatibility of concentrations with the internal market must be supported by a sufficiently cogent and consistent body of evidence (see, to that effect, judgment of 10 July 2008, Bertelsmann and Sony Corporation of America v Impala, C‑413/06 P, EU:C:2008:392, paragraph 50 and the case-law cited).

76      It is true that the Court has held that, in the context of the analysis of a ‘conglomerate-type’ concentration, the quality of the evidence produced by the Commission in order to establish that it is necessary to adopt a decision declaring the concentration incompatible with the internal market is particularly important (judgment of 15 February 2005, Commission v Tetra Laval, C‑12/03 P, EU:C:2005:87, paragraph 44).

77      However, the Court has made clear that that case-law reflects only the essential function of evidence, which is to establish convincingly the merits of an argument or, as in the case of the control of concentrations, to support the conclusions underpinning the Commission’s decisions (see, to that effect, judgments 15 February 2005, Commission v Tetra Laval, C‑12/03 P, EU:C:2005:87, paragraph 41, and of 10 July 2008, Bertelsmann and Sony Corporation of America v Impala, C‑413/06 P, EU:C:2008:392, paragraph 51 and the case-law cited). The specific requirements relating to the quality of the evidence therefore do not, in principle, affect the standard of proof required.

78      Furthermore, the Court has also made clear that the inherent complexity of a theory of competitive harm put forward in relation to a notified concentration is a factor which must be taken into account when assessing the plausibility of the various consequences such a concentration may have, in order to identify those which are most likely to arise, but such complexity does not, of itself, have an impact on the standard of proof which is required (judgment of 10 July 2008, Bertelsmann and Sony Corporation of America v Impala, C‑413/06 P, EU:C:2008:392, paragraph 51).

79      As observed in point 59 of the Advocate General’s Opinion, it must therefore be held that the standard of proof, for the purposes of applying Article 2(2) and (3) of Regulation No 139/2004, does not vary either according to the type of concentration examined by the Commission or according to the inherent complexity of a theory of competitive harm put forward in relation to a notified concentration.

80      In the third and last place, it is apparent from Article 4(1) of Regulation No 139/2004, which requires a concentration to be notified prior to its implementation, and from Article 7(1) of that regulation, which lays down an obligation not to implement that concentration prior to its notification and authorisation, that that regulation establishes a preventive system of review of concentrations.

81      That review can therefore be distinguished from ex post review of agreements between undertakings, decisions by associations of undertakings and concerted practices referred to in Article 101 TFEU and abuses of a dominant position referred to in Article 102 TFEU.

82      In the exercise of that ex ante review of concentrations, the Commission has a margin of discretion with regard to economic matters for the purpose of the application of the substantive rules of Regulation No 139/2004, in particular Article 2 (judgment of 10 July 2008, Bertelsmann and Sony Corporation of America v Impala, C‑413/06 P, EU:C:2008:392, paragraph 144), since it carries out prospective economic analyses seeking to determine the likelihood of certain developments in the relevant market within a foreseeable time frame.

83      Those prospective analyses, which, more often, are complex, are necessarily more uncertain than ex post analyses.

84      The prospective analysis called for in relation to the review of concentrations, which consists of an examination of how such a concentration might alter the parameters of competition on the affected markets in order to establish whether it would give rise to a significant impediment to effective competition, makes it necessary to envisage various chains of cause and effect with a view to ascertaining which of them are the most likely (judgments of 15 February 2005, Commission v Tetra Laval, C‑12/03 P, EU:C:2005:87, paragraph 43; of 10 July 2008, Bertelsmann and Sony Corporation of America v Impala, C‑413/06 P, EU:C:2008:392, paragraph 47; and of 16 January 2019, Commission v United Parcel Service, C‑265/17 P, EU:C:2019:23, paragraph 32). That prospective analysis falls within the margin of discretion with regard to economic matters which is available to the Commission for the purposes of applying the substantive rules of Regulation No 139/2004, in particular Article 2 thereof which justifies the review by the EU Courts of a Commission decision relating to concentrations being confined to ascertaining that the facts have been accurately stated and that there has been no manifest error of assessment (see, to that effect, judgment of 10 July 2008, Bertelsmann and Sony Corporation of America v Impala, C‑413/06 P, EU:C:2008:392, paragraph 144 and the case-law cited).

85      It is true that such an analysis must be carried out with great care since it entails not the examination of past events – for which often many items of evidence are available which make it possible to understand the causes – or of current events, but rather a prediction of events which are more or less likely to occur in future if a decision prohibiting the planned concentration or laying down the conditions for it is not adopted (see, to that effect, judgment of 15 February 2005, Commission v Tetra Laval, C‑12/03 P, EU:C:2005:87, paragraph 42).

86      However, the prospective nature of the economic analysis which the Commission must carry out precludes a requirement for that institution to meet a particularly high standard of proof in order to demonstrate that a concentration would or would not significantly impede effective competition.

87      In those circumstances, having regard, in particular, to the symmetrical structure of Article 2(2) and (3) of Regulation No 139/2004 and to the prospective nature of the Commission’s economic analyses when conducting the review of concentrations, it must be held that, in order to declare that a concentration is incompatible or compatible with the internal market, it is sufficient for the Commission to demonstrate, by means of a sufficiently cogent and consistent body of evidence, that it is more likely than not that the concentration concerned would or would not significantly impede effective competition in the internal market or in a substantial part of it.

88      Consequently, by holding, in paragraph 118 of the judgment under appeal, that the Commission is required to demonstrate with a ‘strong probability the existence of significant impediments’ to effective competition following the concentration and that ‘the standard of proof applicable in the present case is therefore stricter than that under which a significant impediment to effective competition is “more likely than not”’, the General Court applied a standard of proof which does not follow from Regulation No 139/2004, as interpreted by the Court of Justice, and thus made an error in law.

89      Therefore, the first ground of appeal must be upheld.

 The second ground of appeal

90      The second ground of appeal comprises two parts, by which the Commission disputes the General Court’s interpretation of Article 2(3) of Regulation No 139/2004 in the judgment under appeal.

 The first part

–       Arguments of the parties

91      By the first part of its second ground of appeal, the Commission maintains that, in paragraph 90 of the judgment under appeal, the General Court placed the conditions required for a finding that a concentration may have non-coordinated effects on the same footing as those required to demonstrate the existence of dominance.

92      The Commission states that it does not dispute that the degree of harm required to demonstrate a possible significant impediment to effective competition as a result of non-coordinated effects is the same as that required to demonstrate such an impediment as a result of the creation or strengthening of a dominant position. However, by the expression ‘by itself’, used in paragraph 90 of the judgment under appeal in association with the expression ‘merged entity’, the General Court held that the Commission can prohibit a concentration only if it can establish that that entity will benefit from market power equivalent to that ensured by a dominant position.

93      CK Telecoms contends that the Commission is challenging a general finding by the General Court which did not serve as the basis for an analysis in concreto and that, consequently, the first part of the Commission’s second ground of appeal is ineffective.

–       Findings of the Court

94      In paragraph 90 of the judgment under appeal, the General Court found that Article 2(3) of Regulation No 139/2004 ‘allow[s] the Commission to prohibit, in certain circumstances, on oligopolistic markets concentrations which, although not giving rise to the creation or strengthening of an individual or collective dominant position, are liable to affect the competitive conditions on the market to an extent equivalent to that attributable to such positions, by conferring on the merged entity the power to enable it to determine, by itself, the parameters of competition and, in particular, to become a price maker instead of remaining a price taker’.

95      It should be stated that, as CK Telecoms observed, that paragraph 90 involves a general finding by the General Court, without establishing a link with any error allegedly made by the Commission in applying the concept of a ‘significant impediment to effective competition’ within the meaning of Article 2(3) of Regulation No 139/2004. In addition, as the Advocate General noted in point 70 of her Opinion, the Commission fails to identify any paragraph of the judgment under appeal which is based on that finding.

96      In that regard, it is apparent from the Court of Justice’s settled case-law that arguments directed against grounds included in a decision of the General Court purely for the sake of completeness cannot lead to the decision being set aside and are therefore ineffective (judgment of 23 March 2023, PV v Commission, C‑640/20 P, EU:C:2023:232, paragraph 191 and the case-law cited). Even if the first part of the second ground of appeal were well founded, it would not be capable of invalidating the judgment under appeal, since that part relates to a ground of that judgment which has not been established as contributing to the support of the operative part of that judgment.

97      It follows that the first part of the second ground of appeal must be rejected as being ineffective.

 The second part

–       Arguments of the parties

98      By the second part of the second ground of appeal, the Commission submits that, in paragraphs 95 and 96 of the judgment under appeal, the General Court made an error of law in holding that Article 2(3) of Regulation No 139/2004, read in the light of recital 25 of that regulation, must be interpreted as meaning that, in the absence of the creation or strengthening of a dominant position following a concentration, a significant impediment to effective competition can be established only if the two cumulative conditions set out in that recital are fulfilled, namely (i) the elimination of the important competitive constraints that the merging parties had exerted upon each other and (ii) a reduction of competitive pressure on the remaining competitors.

99      According to the Commission, such an interpretation compromises the purpose of effective merger control set out in recital 24 of that regulation and has the effect, inter alia, of preventing it from developing theories of harm which do not satisfy the conditions set out in paragraph 96 of the judgment under appeal, such as, for example, the second theory of harm put forward in the present case, based on a reduction of the competitive pressure exerted by the remaining competitors on the merged entity, due to the market position of that entity following the concentration.

100    CK Telecoms contends that it is apparent from the wording of recital 25 of Regulation No 139/2004, in particular from the conjunction ‘as well as’, which was reproduced in the Horizontal Merger Guidelines and in the decision at issue, that that recital sets out two cumulative conditions. An interpretation to the contrary would allow the Commission to prohibit all horizontal mergers, since they necessarily lead to a reduction of competition between the parties concerned.

–       Findings of the Court

101    The General Court, in essence, held in paragraph 96 of the judgment under appeal, that Article 2(3) of Regulation No 139/2004 must be interpreted in the light of recital 25 of that regulation. In that regard, it adopted the premiss that that recital lays down two cumulative conditions in order that non-coordinated effects resulting from a concentration may, in certain circumstances, result in a significant impediment to effective competition, namely, first, the elimination of important competitive constraints that the merging parties had exerted upon each other and, second, the reduction of competitive pressure on the remaining competitors.

102    In paragraph 97 of the judgment under appeal, the General Court concluded that ‘it follows that the mere effect of reducing competitive pressure on the remaining competitors is not, in principle, sufficient in itself to demonstrate a significant impediment to effective competition in the context of a theory of harm based on non-coordinated effects’.

103    It is in the light of that interpretation of Article 2(3) of Regulation No 139/2004 that the General Court examined the first, third and fourth pleas in law, as is apparent from paragraph 105 of the judgment under appeal.

104    In that regard, it should be recalled, at the outset, that the preamble to an EU act may explain the content of the provisions of that act and that the recitals of such an act constitute important elements for the purposes of interpretation, which may clarify the intentions of the author of that act (judgment of 19 December 2019, Puppinck and Others v Commission, C‑418/18 P, EU:C:2019:1113, paragraph 75 and the case-law cited).

105    However, the preamble to an EU act has no binding legal force and cannot be relied on as a ground either for derogating from the actual provisions of the act in question or for interpreting those provisions in a manner that is clearly contrary to their wording (judgment of 19 December 2019, Puppinck and Others v Commission, C‑418/18 P, EU:C:2019:1113, paragraph 76 and the case-law cited).

106    As is apparent from recitals 6 and 24 of Regulation No 139/2004, that regulation seeks to establish effective control of all concentrations in terms of their effect on the structure of competition in the European Union, in particular, to ensure effective and undistorted competition in the internal market and to ensure a policy conducted in accordance with the principle of an open market economy with free competition.

107    In that regard, it is apparent, in essence, from recital 25 of that regulation that the regulation also concerns the incompatibility with the internal market of a concentration between undertakings active on an oligopolistic market where that concentration would significantly impede effective competition without the entity resulting from that concentration holding a dominant position.

108    In particular, it is apparent from that recital 25 that while ‘many oligopolistic markets exhibit a healthy degree of competition [the fact remains that], under certain circumstances, concentrations involving the elimination of important competitive constraints that the merging parties had exerted upon each other, as well as a reduction of competitive pressure on the remaining competitors, may, even in the absence of a likelihood of coordination between the members of the oligopoly, result in a significant impediment to effective competition’.

109    It is apparent, in essence, from the penultimate sentence of that recital 25 that the effective control provided for in Regulation No 139/2004 extends to all concentrations which would significantly impede effective competition, in the internal market or in a substantial part of it, including concentrations giving rise to non-coordinated effects. That effective control forms part of the general objective of Regulation No 139/2004, which is reflected in recital 5 thereof, consisting in preventing a process of reorganisation from resulting in lasting damage to competition in the internal market or in a substantial part of it.

110    In order to ensure effective and undistorted competition in the internal market and to ensure a policy conducted in accordance with the principle of an open market economy with free competition, Regulation No 139/2004 seeks to establish effective control of all concentrations which would significantly impede effective competition, including those having non-coordinated effects on oligopolistic markets. Accordingly, aside from the fact that a recital of that regulation cannot, in any event, limit the scope of the provisions of that regulation, it cannot be considered that the effective control of concentrations carried out on such markets which may give rise to non-coordinated effects must be limited to cases which, simultaneously, fall within both situations set out in recital 25 of that regulation.

111    As the Advocate General noted, in essence, in points 74 to 76 of her Opinion, the conjunction ‘as well as’ is not sufficient to invalidate that interpretation. To interpret Article 2(3) of Regulation No 139/2004, read in the light of recital 25 of that regulation, as meaning that those two situations are cumulative conditions in order for a finding to be made of a significant impediment to effective competition resulting from a concentration having non-coordinated effects on an oligopolistic market would have the effect of limiting effective control of that type of concentration solely to those cases in which the Commission can demonstrate that the concentration concerned is capable both of eliminating important competitive constraints between the parties to that transaction and of reducing competitive pressure on the remaining competitors active on the market concerned.

112    Accordingly, such an interpretation would mean that the elimination of the important competitive constraints that the merging parties had exerted upon each other and the unilateral price increase which might result therefrom would never, in themselves, be sufficient to demonstrate a significant impediment to effective competition.

113    Such a restrictive interpretation of Article 2(3) of Regulation No 139/2004 would be incompatible with the objective of that regulation, recalled in paragraph 109 of the present judgment, which is to establish effective control of all concentrations which would significantly impede effective competition, in the internal market or in a substantial part of it, including those giving rise to non-coordinated effects.

114    In those circumstances, by holding, in paragraph 96 of the judgment under appeal, that Article 2(3) of Regulation No 139/2004, read in the light of recital 25 of that regulation, must be interpreted as meaning that, in the absence of the creation or strengthening of a dominant position following a concentration on an oligopolistic market, a significant impediment to effective competition can be established only if the Commission demonstrates that two cumulative conditions are satisfied, namely, first, the elimination of important competitive constraints that the merging parties had exerted upon each other and, second, the reduction of competitive pressure on the remaining competitors, the General Court erred in law.

115    In the light of the foregoing considerations, the second part of the second ground of appeal must be upheld.

116    It follows that the second ground of appeal, alleging misinterpretation of Article 2(3) of Regulation No 139/2004, is well founded.

 The third ground of appeal

117    The third ground of appeal comprises four parts, alleging, first, that the General Court exceeded the limits of its judicial review in interpreting the concepts of ‘important competitive force’ and ‘close competitors’, second, distortion both of the decision at issue and of the Commission’s defence as well as misinterpretation of the concept of ‘important competitive force’, third, misinterpretation of the concept of ‘close competitors’ and distortion of the decision at issue and, fourth, which is put forward in the alternative, infringement of the obligation to state reasons as regards the possible incompatibility of the Horizontal Merger Guidelines with Regulation No 139/2004.

 The first part

–       Arguments of the parties

118    By the first part of its third ground of appeal, the Commission submits, in essence, that, in interpreting, in paragraphs 174 and 242 of the judgment under appeal, the concepts of ‘important competitive force’ and ‘close competitors’, the General Court departed from the definitions of those economic concepts in the Horizontal Merger Guidelines and from the economic approach set out in those guidelines. In the Commission’s opinion, the General Court therefore failed to have regard to the Commission’s margin of discretion with regard to economic matters and substituted its own economic assessment for that of the Commission. In so doing, the General Court exceeded the limits of judicial review of Commission decisions declaring a concentration compatible or incompatible with the internal market.

119    In particular, the Commission submits that the General Court has neither the jurisdiction nor expertise to depart from the economic concepts contained in the Horizontal Merger Guidelines and to follow an economic approach which differs from that set out in those guidelines. According to the Commission, the General Court’s jurisdiction is limited to reviewing the lawfulness of those guidelines.

120    CK Telecoms contends that the General Court did not exceed the limits of judicial review in its interpretation and application of the concepts of ‘important competitive force’ and ‘close competitors’. On the contrary, in the judgment under appeal, the General Court assessed the evidence by applying the test derived from settled case-law, under which the Commission’s margin of discretion with regard to economic matters is without prejudice to the jurisdiction of the EU Courts to review the Commission’s interpretation of information of an economic nature.

–       Findings of the Court

121    Recital 28 of Regulation No 139/2004 provides that, in order to clarify and explain the Commission’s appraisal of concentrations under that regulation, it is appropriate for the Commission to publish guidance which should provide a sound economic framework for the assessment of concentrations with a view to determining whether or not they may be declared compatible with the internal market.

122    The Commission therefore adopted the Horizontal Merger Guidelines, which establish the methodology which the Commission has bound itself to use for the purposes of its assessment of whether there is a significant impediment to effective competition, within the meaning of Regulation No 139/2004.

123    However, although the Commission cannot depart from such guidelines without justification, under pain of being found, where appropriate, to be in breach of the general principles of law, they may not be regarded as rules of law which the administration is always bound to observe, and do not constitute the legal basis for the decisions taken by the Commission in the matter concerned (see, to that effect, judgment of 28 June 2005, Dansk Rørindustri and Others v Commission, C‑189/02 P, C‑202/02 P, C‑205/02 P to C‑208/02 P and C‑213/02 P, EU:C:2005:408, paragraphs 209, 211 and 213). The EU Courts nevertheless retain jurisdiction to interpret them, inter alia, where, in its decisions authorising or prohibiting a concentration, the Commission has relied on those guidelines in order to determine whether or not the concentration concerned would give rise to a significant impediment to effective competition.

124    It is true that, as has been recalled in paragraph 84 of the present judgment, the Commission has a margin of discretion with regard to economic matters for the purpose of applying the substantive rules of Regulation No 139/2004, in particular Article 2 thereof, which justifies the review by the EU Courts of a Commission decision relating to concentrations being confined to ascertaining that the facts have been accurately stated and that there has been no manifest error of assessment.

125    However, that does not mean that the EU Courts must refrain from reviewing the Commission’s interpretation of information of an economic nature. Indeed, the EU Courts, which, as recalled by the Advocate General in points 73 and 85 of her Opinion, cannot be bound by the Horizontal Merger Guidelines as such, must not only establish, among other things, whether the evidence relied on is factually accurate, reliable and consistent but also whether that evidence contains all the information which must be taken into account in order to assess a complex situation and whether it is capable of substantiating the conclusions drawn from it (see, to that effect, judgment of 10 July 2008, Bertelsmann and Sony Corporation of America v Impala, C‑413/06 P, EU:C:2008:392, paragraph 145 and the case-law cited).

126    Nor does that margin of discretion on the part of the Commission mean that the EU Courts must refrain from reviewing the Commission’s interpretation of concepts of EU law requiring an economic analysis when they are implemented.

127    In that regard, it should be recalled that in the area of competition law, the EU Courts have already, on a number of occasions, interpreted concepts requiring an economic analysis when they are implemented, such as the concept of ‘dominant position’ (judgment of 14 February 1978, United Brands and United Brands Continentaal v Commission, 27/76, EU:C:1978:22, paragraphs 65 and 66), the concept of ‘relevant market’ (judgments of 9 November 1983, Nederlandsche Banden-Industrie-Michelin v Commission, 322/81, EU:C:1983:313, paragraph 37, and of 6 October 1994, Tetra Pak v Commission, T‑83/91, EU:T:1994:246, paragraph 63) and the concept of a ‘margin squeeze of competitors’ (judgment of 25 March 2021, Slovak Telekom v Commission, C‑165/19 P, EU:C:2021:239, paragraph 73 and the case-law cited).

128    The concepts of ‘important competitive force’ and ‘close competitors’, to which the Horizontal Merger Guidelines refer, are included among the factors which may have a bearing on the likelihood that significant non-coordinated effects will result from a merger and, therefore, whether a ‘significant impediment to effective competition’ within the meaning of Article 2(2) and (3) of Regulation No 139/2004 may be found to exist.

129    It follows that, even though the concepts of ‘important competitive force’ and ‘close competitors’ require an economic analysis when they are implemented, the EU Courts have jurisdiction to interpret them when reviewing Commission merger control decisions.

130    In those circumstances, it must be stated that, in the present case, the General Court, in interpreting the concepts of ‘important competitive force’ and ‘close competitors’, did not exceed the limits of its judicial review.

131    It follows that the first part of the Commission’s third ground of appeal must be rejected as being unfounded.

 The second part

–       Arguments of the parties

132    By the second part of its third ground of appeal, the Commission puts forward three complaints, alleging, first, distortion of the decision at issue, second, distortion of the Commission’s defence and, third, misinterpretation of the concept of ‘important competitive force’.

133    By its first complaint, the Commission complains that the General Court erred in finding, in paragraph 171 of the judgment under appeal, that it was apparent from the decision at issue that the fact that a party to the concentration is classified as an ‘important competitive force’ on an oligopolistic market is sufficient for the view to be taken that the concentration would give rise to a significant impediment to effective competition. That observation by the General Court is, the Commission argues, contradicted by paragraph 155 of the judgment under appeal, according to which it is apparent from the decision at issue, in particular recital 777 of that decision, that the fact that ‘Three constitute[d] an important competitive force in the [retail market] … pursuant to paragraph 37 of the … Guidelines, or in any event it exert[ed] an important competitive constraint on that market’ was only one of the factors taken into account by the Commission in concluding that the concentration would give rise to significant non-coordinated effects.

134    By its second complaint, the Commission submits that, in paragraph 170 of the judgment under appeal, the General Court distorted paragraph 39 of its defence, which led the General Court to create its own definition of the concept of ‘important competitive force’, which differs from that established in paragraph 37 of the Horizontal Merger Guidelines. It is apparent, in particular, from paragraph 39 of the defence and from paragraph 13 of the Commission’s rejoinder that the Commission simply provided an example in those documents, without stating that an ‘important competitive force’ must necessarily compete in a particularly aggressive way and force competitors to follow that conduct.

135    However, it is apparent from paragraphs 170 and 216 of the judgment under appeal that the General Court took that example and converted it into a definition of the concept of ‘important competitive force’.

136    By its third and final complaint, the Commission submits that the General Court erred in imposing on it, in paragraphs 170 and 216 of the judgment under appeal, excessive requirements in relation to classifying an undertaking as an ‘important competitive force’, under which the undertaking concerned must stand out from its competitors in terms of impact on competition and, in particular, compete particularly aggressively in terms of prices and force the other players on the market to align with its prices.

137    As regards the Commission’s first complaint, CK Telecoms contends that, in its previous practice and in particular in the cases referred to in paragraph 164 of the judgment under appeal, the Commission classified one or two of the parties to the concentrations examined as an ‘important competitive force(s)’, that finding being sufficient for the view to be taken that the concentration concerned could give rise to a significant impediment to effective competition.

138    As regards the Commission’s second complaint, CK Telecoms submits that paragraph 39 of the Commission’s defence was not limited to providing an example of an ‘important competitive force’.

139    As regards the Commission’s third and final complaint, CK Telecoms submits that the General Court did not depart from the Horizontal Merger Guidelines and was fully entitled to find that an ‘important competitive force’ had to stand out from its competitors in terms of impact on competition.

140    To require an ‘important competitive force’ to stand out from its competitors in terms of impact on competition is the minimum required in order for the view to be taken that, in an oligopolistic market, an undertaking may fall within that concept. If that were not the case, any competitor active on an oligopolistic market could be classified as an ‘important competitive force’ and the Commission would be able to prohibit almost all horizontal mergers.

141    Accordingly, in order to classify an undertaking as an ‘important competitive force’ on an oligopolistic market, it must be demonstrated that that undertaking exerts particularly strong constraints on other competitors.

–       Findings of the Court

142    As regards the first complaint, which alleges distortion of the decision at issue, it must be recalled that, in accordance with the settled case-law of the Court of Justice, a distortion must be obvious from the documents in the Court’s file, without any need for a new assessment of the facts and the evidence (judgment of 25 July 2018, Orange Polska v Commission, C‑123/16 P, EU:C:2018:590, paragraph 75).

143    In the present case, the General Court found in paragraph 171 of the judgment under appeal that ‘it is apparent from [the decision at issue] that, as regards the elimination of an “important competitive force”, the Commission is of the opinion that the mere decline in the competitive pressure which would result, in particular, from the loss of an undertaking having more of an influence on competition than its market share would suggest is sufficient, in itself, to prove a significant impediment to effective competition’.

144    The General Court based that finding on a reading of all of the recitals of the decision at issue dealing, in particular, with the nature of the concept of ‘important competitive force’.

145    Contrary to the General Court’s finding in paragraph 171 of the judgment under appeal, it is not apparent from the decision at issue that the Commission was of the view that the elimination of an ‘important competitive force’ would be sufficient in the present case, in itself, to prove a significant impediment to effective competition.

146    Rather, it is apparent from the main elements in the sections entitled ‘Competitive assessment’ and ‘The Legal test’, and, more specifically, from recitals 313 and 321 of the decision at issue, that the Horizontal Merger Guidelines list a number of factors which are relevant for determining whether a concentration may result in non-coordinated effects.

147     It is true that, in those two recitals, the Commission stated, inter alia, that not all those factors need to be present for such effects to be likely. However, as the Advocate General observed in point 97 of her Opinion, the Commission did not infer therefrom that the presence of only one of those factors is sufficient for a finding that the concentration could lead to a significant impediment to effective competition.

148    In footnote 263 to recital 313 of the decision at issue, the Commission explicitly referred to paragraph 26 of the Horizontal Merger Guidelines, in accordance with which the fact that one of the parties to the concentration may be classified as an ‘important competitive force’ is one of the factors mentioned in those guidelines as being capable of being taken into account in order to establish whether that concentration would give rise to a significant impediment to effective competition.

149    Furthermore, as the Commission observes, the General Court, in paragraph 155 of the judgment under appeal, itself observes that it is apparent from the decision at issue that Three being classified as an ‘important competitive force’ is one of the factors taken into account by the Commission in concluding that the concentration would give rise to non-coordinated effects.

150    It follows that the General Court distorted that decision in paragraph 171 of the judgment under appeal.

151    The first complaint in the second part of the third ground of appeal must therefore be upheld.

152    As regards the second complaint, which alleges that the General Court distorted, in paragraph 170 of the judgment under appeal, paragraph 39 of the Commission’s defence, which led the General Court to establish a definition of ‘important competitive force’ from an example of that concept, suffice it to state that, even if, in paragraph 170 of the judgment under appeal, the General Court did distort the Commission’s defence, such a distortion cannot lead to the judgment under appeal being set aside, in particular because the Commission’s written observations submitted in the proceedings before the General Court concerning the concept of ‘important competitive force’ cannot be regarded as decisive for the purpose of determining what is covered by that concept.

153    It follows that the second complaint in the second part of the third ground of appeal must be rejected as being ineffective.

154    As regards the third and last complaint, alleging that the General Court erred in law because it imposed excessive requirements in order to classify an undertaking as an ‘important competitive force’, it should be recalled that, in paragraphs 170 and 216 of the judgment under appeal, that court adopted a definition of the concept of ‘important competitive force’ under which the undertaking concerned must stand out from its competitors in terms of the impact of its pricing policy on competitive dynamics on the market concerned and, in particular, must compete particularly aggressively in terms of price and force the other players on the market to align with its prices.

155    The General Court stated in paragraphs 173 and 175 of that judgment that the approach taken by the Commission in the decision at issue amounts, in practice, to confusing the concept of ‘significant impediment to effective competition’ referred to in Article 2(3) of Regulation No 139/2004, the concept of ‘elimination of [an] important competitive [constraint]’ set out in recital 25 of that regulation, and the concept of the elimination of an ‘important competitive force’. Such confusion would lead to a broad interpretation of Article 2(3), under which any elimination of an ‘important competitive force’ would amount to the elimination of an important competitive constraint which, in turn, would justify a finding of a significant impediment to effective competition.

156    In addition, in paragraph 174 of the judgment under appeal, the General Court held, in essence, that, while an undertaking was not required to stand out from its competitors in terms of impact on competition in order to be classified as an ‘important competitive force’, any undertaking on an oligopolistic market which exerts competitive pressure could fall within that concept.

157    In that context, the General Court found, in paragraph 216 of that judgment, that the Commission had not demonstrated to the requisite legal standard that Three fell within that concept.

158    In that regard, it should, first, be recalled that, as is apparent from recitals 6, 24 and 25 of Regulation No 139/2004, that regulation seeks to establish effective control of all concentrations which would significantly impede effective competition, in the internal market or in a substantial part of it, including concentrations giving rise to non-coordinated effects.

159    Second, as confirmed by paragraph 24 of the Horizontal Merger Guidelines, the most direct effect of a merger will be the loss of competition between the merging firms.

160    Third, under a combined reading of paragraphs 26, 37 and 38 of the Horizontal Merger Guidelines, the elimination of an ‘important competitive force’ is, in principle, one of the factors which may influence whether significant non-coordinated effects are likely to result from a merger and which thus make it possible to assess, inter alia, whether that concentration would result in the elimination of important competitive constraints that the merging parties had exerted upon each other.

161    In that context, it must be held that the requirements for classifying an undertaking as an ‘important competitive force’, which have a direct impact on the use of that classification as a factor which is relevant for determining whether there is a significant impediment to effective competition, should not be such as to preclude the Commission from declaring incompatible with the internal market concentrations which could give rise to significant non-coordinated effects and, consequently, significantly harm effective competition. If that were not the case, the full effectiveness of Article 2(2) and (3) of Regulation No 139/2004 and, in particular, the practical effect of those provisions could be called into question.

162    In that regard, the fact that a party to a concentration on an oligopolistic market does not stand out from its competitors by being ‘particularly aggressive’ in terms of price does not mean that a concentration to which such an undertaking is a party could not alter the competitive dynamic to a significant and detrimental extent. It is common ground that merger control seeks precisely to examine how a concentration could alter the factors determining the state of competition on a given market in order to ascertain whether the concentration would result in a significant impediment to effective competition, without it being decisive in that regard that an undertaking covered by that concentration is a ‘particularly aggressive’ undertaking on that market.

163    Indeed, as is confirmed, in essence, by paragraph 38 of the Horizontal Merger Guidelines, it cannot be ruled out that, on a given oligopolistic market, a number of undertakings may be classified as an ‘important competitive force’.

164    Moreover, it should be recalled that the Commission’s practice in previous decisions does not itself serve as a legal framework for merger control and can give only an indication (see, by analogy, judgment of 24 September 2009, Erste Group Bank and Others v Commission, C‑125/07 P, C‑133/07 P, C‑135/07 P and C‑137/07 P, EU:C:2009:576, paragraph 233 and the case-law cited). Accordingly, the fact that the Commission, in previous decisions, classified as an ‘important competitive force’ certain undertakings which were unique in their ‘aggression’ on the market concerned and had grown their presence on that market faster than any other competitor does not mean that those are the only situations capable of giving rise to such a classification.

165    Lastly, price is often not the only important parameter for assessing competitive dynamics, in particular in differentiated product markets in which quality and innovation could play a key role in the positioning of the products concerned. Therefore, an exclusively price-focused approach for the purposes of classifying an undertaking as an ‘important competitive force’ would necessarily be incomplete.

166    Therefore, the concept of ‘important competitive force’ cannot be applied exclusively to undertakings which compete particularly aggressively in terms of price and which force their competitors on the market to align with their prices or to undertakings whose pricing policy is likely to alter significantly the competitive dynamics of the market concerned.

167    In those circumstances, it must be held that, in order to classify an undertaking as an ‘important competitive force’, it is sufficient, as set out in paragraph 37 of the Horizontal Merger Guidelines, that it has more of an influence on the competitive process than its market share or similar measures would suggest.

168    Accordingly, in the present case, in finding, in paragraphs 170 and 216 of the judgment under appeal, that, in order to classify Three as an ‘important competitive force’, the Commission was required to demonstrate that Three competed particularly aggressively in terms of price and that it forced the other players on the market to align with its prices or that its pricing policy was likely to alter significantly the competitive dynamics on the market, the General Court erred in law.

169    In the light of the findings made in paragraphs 151 and 168 of the present judgment, the second part of the third ground of appeal must be upheld.

 The third part

–       Arguments of the parties

170    By the third part of its third ground of appeal, the Commission puts forward two complaints.

171    By its first complaint, the Commission submits that, by requiring it, in paragraph 242 of the judgment under appeal, to demonstrate that the parties to the concentration are not ‘close competitors’ but rather ‘particularly close competitors’, the General Court imposed an excessive requirement as regards the assessment of the closeness of competition between those parties.

172    According to the Commission, the General Court erred in assuming in paragraph 247 of the judgment under appeal that on an oligopolistic market such as the United Kingdom mobile telecommunications market, with four mobile network operators, all those operators are, by definition, close to a greater or lesser extent.

173    In that regard, the Commission points out that each market has its own dynamics. Accordingly, on an oligopolistic market characterised by the supply of differentiated products, it is possible that the products offered by two undertakings on that market have a relatively low degree of substitutability or concentrate almost exclusively on different market segments. Those two undertakings could not therefore be regarded as close competitors. Therefore, if they were to merge, the Commission could not rely on closeness of competition as a relevant factor in concluding that there was a significant impediment to effective competition. By contrast, according to the Commission, if those two undertakings compete closely in the same segments of that oligopolistic market, thus showing that ‘rivalry between [them] has been an important source of competition on the market’, within the meaning of paragraph 28 of the Horizontal Merger Guidelines, the Commission cannot be required to demonstrate that the merging parties are the ‘closest competitors’ or ‘particularly close competitors’.

174    By its second complaint, the Commission complains that the General Court distorted the decision at issue by finding, in particular in paragraph 249 of the judgment under appeal, that it had relied on the premiss that the closeness of competition between Three and O2 was sufficient to make a finding that the proposed concentration would give rise to a significant impediment to effective competition. As the General Court noted in paragraph 227 of the judgment under appeal, the closeness of competition between Three and O2 is only one of the factors used in the decision at issue in order to conclude that the proposed concentration would give rise to non-coordinated effects.

175    CK Telecoms contends that the Commission’s first complaint is based on a selective and erroneous reading of the judgment under appeal. The General Court took proper account of the Horizontal Merger Guidelines and of the fact that the closeness of competition between Three and O2 is an important factor in the present case.

176    However, those guidelines do not determine precisely the degree of closeness necessary in order to classify the undertakings concerned as ‘close competitors’.

177    In addition, CK Telecoms argues that the Commission failed to apply in the decision at issue the criteria established in those guidelines in order to examine the closeness of competition between Three and O2.

178    According to CK Telecoms, the requirement of ‘particular’ closeness is in line with the overarching prohibition standard of a significant impediment to effective competition. Only a particular degree of closeness of competition could be evidence of such an impediment.

179    As regards the second complaint, CK Telecoms takes the view that the General Court did not distort the decision at issue in paragraph 249 of the judgment under appeal.

–       Findings of the Court

180    As regards the first complaint, alleging that the General Court erred in requiring the Commission, in particular, in paragraph 242 of the judgment under appeal, to demonstrate, in the present case, that the parties to the concentration are ‘particularly close competitors’, it should be noted that the General Court’s assessment of the degree of closeness of competition between the parties to the concentration forms part of the examination of the first theory of harm put forward by the Commission in the decision at issue relating to non-coordinated effects on the retail market.

181    In paragraph 128 of the judgment under appeal, the General Court observed that, in the context of that theory, the Commission relied on the important competitive constraint exerted by Three and O2, on the closeness of competition between those two undertakings, on their market shares and on the incentives for the merged entity to increase prices as well as on the ability of its competitors to compete in order to conclude, in recital 1226 of the decision at issue, that the proposed concentration was ‘likely to give rise to non-coordinated anticompetitive effects on the retail market’.

182    In that context, the General Court, first, noted, in paragraph 234 of the judgment under appeal, that the concept of ‘close competitor’ does not appear in Regulation No 139/2004, but only in the Horizontal Merger Guidelines.

183    Second, in paragraphs 235 and 241 of that judgment, the General Court stated, in essence, that the applicability of Article 2(3) of Regulation No 139/2004, read in the light of recital 25 of that regulation, requires the elimination of important competitive constraints that the merging parties had exerted upon each other, which constitutes the most direct unilateral effect of a concentration on an oligopolistic market.

184    Third, in paragraphs 242, 247 and 249 of that judgment, the General Court held, in essence, that the Commission had to demonstrate, in the case of an oligopolistic market on which all operators are, by definition, close to a greater or lesser extent, not that those parties are close competitors, but rather that they are ‘particularly close’ competitors.

185    Finally, in paragraphs 249 and 250 of the judgment under appeal, the General Court upheld CK Telecoms’ arguments concerning the weak probative value of the analysis of the closeness of competition between Three and O2. The General Court’s reasoning for that position was that Three and O2 were only relatively close competitors in some of the segments of a concentrated market comprising four mobile network operators. The General Court held that that factor alone was not sufficient to prove, in the present case, the elimination of the important competitive constraints which the parties to the proposed concentration exerted upon each other and to establish a significant impediment to effective competition; if that were not the case, any concentration resulting in a reduction from four to three operators would as a matter of principle be prohibited.

186    In that regard, as has been pointed out in paragraph 159 of the present judgment, the most direct effect of a merger on an oligopolistic market will be the loss of competition between the merging firms.

187    As confirmed in paragraphs 26 and 28 to 30 of the Horizontal Merger Guidelines, while closeness of competition between the merging parties constitutes significant evidence in order to assess the possible elimination of the important competitive constraints exerted between those parties, that closeness is only one of the factors making possible an assessment of whether significant non-coordinated effects are likely to result from a merger.

188    In that regard, the Commission was correct in stating, in paragraph 28 of the Horizontal Merger Guidelines, that products may be differentiated within a relevant market such that some products are closer substitutes than others and that the higher the degree of substitutability between the merging firms’ products, the more likely it is that the merging firm will raise prices significantly post-merger. Therefore, as the Advocate General noted, in essence, in point 121 of her Opinion, a higher degree of closeness of competition between the parties to a concentration may constitute evidence that it is more likely than not that that concentration will significantly impede effective competition in the internal market or in a significant part of it, whereas a lesser degree of closeness of competition between those parties may constitute evidence to the contrary.

189    In that context, to require, for the purposes of assessing the closeness of competition between the parties to a concentration, that those parties be ‘particularly close’ competitors implies that there is a very high level of substitutability between the parties’ products on a differentiated products market. However, such a level of substitutability is not necessarily required. Even where substitutability between the merging parties’ products is not particularly high, there may also be a lower level of substitutability between those parties’ products and the products of undertakings which are not party to the concentration, which is capable of incentivising the parties to the concentration to increase the prices of their products.

190    In addition, as stated, in essence, in paragraph 28 of the Horizontal Merger Guidelines, high pre-merger margins may also make significant post-merger price increases more likely. Such margins may also indicate that the parties to the concentration concerned are neither the closest competitors nor particularly close competitors.

191    Therefore, it cannot be concluded that only a concentration between particularly close competitors could significantly impede effective competition on the relevant market.

192    Consequently, by requiring the Commission, in particular in paragraphs 242 and 247 of the judgment under appeal, to demonstrate that the merging parties are not close competitors, but rather ‘particularly close’ competitors, the General Court erred in law.

193    It follows that the first complaint in the third part of the third ground of appeal must be upheld.

194    As regards the second complaint, the Commission thereby complains that the General Court distorted the decision at issue by finding, in particular in paragraph 249 of the judgment under appeal, that, in that decision, the Commission had relied on the premiss that the closeness of competition between Three and O2 on the oligopolistic market at issue was sufficient, in itself, to make a finding that the concentration would give rise to a significant impediment to effective competition.

195    In that regard, it should be stated that in paragraph 249 of the judgment under appeal, the General Court found that ‘although it may indeed be established that Three and O2 are relatively close competitors in some of the segments of a concentrated market comprising four mobile network operators, that factor alone is not sufficient to prove, in the present case, the elimination of the important competitive constraints which the parties to the concentration exerted upon each other and cannot suffice to establish a significant impediment to effective competition; if that were not the case, any concentration resulting in a reduction from four to three operators would as a matter of principle be prohibited’.

196    As the Commission maintains, the decision at issue does not include any factor asserting that the closeness of competition between Three and O2 was, in itself, sufficient to make a finding that the proposed concentration was likely to result in a significant impediment to effective competition. On the contrary, as has been recalled in paragraph 146 of the present judgment, the Commission stated, in recitals 313 and 321 of the decision at issue, that the Horizontal Merger Guidelines list a number of factors, including that of closeness of competition, which are relevant in order to determine whether a concentration may result in non-coordinated effects.

197    The second complaint and, therefore, the third part of the third ground of appeal in its entirety must therefore be upheld.

198    The second and third parts of the third ground of appeal must therefore be upheld, there being no need to examine the fourth part of that ground of appeal, submitted in the alternative.

 The fourth ground of appeal

199    The fourth ground of appeal comprises two parts. The first part alleges, first, distortion of the Commission’s arguments concerning its quantitative analysis of the proposed concentration’s effects on prices and, second, that the General Court erred in taking the view that, in the present case, the price increase was not significant. The second part alleges that the General Court erred in requiring the Commission to take into account ‘standard’ efficiencies in its analysis.

 The first part

–       Arguments of the parties

200    By the first part of its fourth ground of appeal, the Commission puts forward two complaints.

201    By its first complaint, the Commission complains that the General Court distorted its pleadings in finding, in paragraph 273 of the judgment under appeal, that it was not disputed that the price increase to which the proposed concentration could give rise was [confidential] (1) %, whereas it is apparent both from paragraph 157 of the defence and from paragraph 61 of the rejoinder that the Commission challenged that figure before the General Court. It is clear from those paragraphs that the Commission challenged the figures put forward by CK Telecoms and maintained, before the General Court, that that price increase was [confidential]%.

202    By its second complaint, the Commission complains that the General Court erred in law, in paragraph 273 of the judgment under appeal, by suggesting that the price increase to which the proposed concentration could give rise was not significant since it was lower than predicted price increases in certain earlier decisions authorising concentrations subject to conditions.

203    In that regard, the Commission submits that the General Court ought not to have compared the proposed concentration with concentrations which had already given rise, first, to Commission Decision C(2014) 3561 final of 28 May 2014 declaring a concentration compatible with the internal market and the EEA Agreement (Case M.6992 – Hutchison 3G UK/Telefónica Ireland), published in summary form in the Official Journal of the European Union of 13 August 2004 (OJ 2014 C 264, p. 6, ‘the Irish case’) and, second, Commission Decision C(2014) 4443 of 2 July 2014 declaring a concentration compatible with the internal market and the functioning of the EEA Agreement (Case M.7018 – Telefónica Deutschland/E-Plus), published in summary form in the Official Journal of the European Union of 13 March 2015 (OJ 2015 C 86, p. 10, ‘the German case’). The Commission submits that the comparison made by the General Court is based on a manifestly erroneous reading of the Commission’s decisions in those two cases. Unlike the present case, the Commission authorised the concentrations involved in the Irish and German cases because the parties in those cases had proposed remedies which were considered sufficient to eliminate a significant impediment to effective competition.

204    CK Telecoms contends, in the first place, that, by the first part of the fourth ground of appeal, the Commission is criticising questions of fact and that that part is thus inadmissible.

205    In the second place, CK Telecoms maintains that the first part of the fourth ground of appeal is ineffective. In paragraphs 264 to 281 of the judgment under appeal, the General Court carried out an assessment which led it to find, in paragraph 282 of that judgment, that the quantitative analysis carried out in the present case lacked probative value, since the Commission had not demonstrated that prices would increase significantly following the elimination of the important competitive constraints which the merging parties exerted upon each other. CK Telecoms states that, in paragraph 268 of the judgment under appeal, the General Court rejected the evidentiary value of the Commission’s quantitative analysis, which the Commission does not dispute.

206    In the third and last place, CK Telecoms submits that the General Court did not err in law in its assessment of the Commission’s quantitative analysis. In that regard, it justified the need to define a threshold above which the result of that analysis could indicate that a merger is likely to lead to significant price increases.

–       Findings of the Court

207    By its first complaint, the Commission is not criticising matters of fact, but alleging distortion of the content of its pleadings at first instance. Therefore, that complaint cannot be rejected as being inadmissible (see, to that effect, judgment of 29 November 2018, Alcohol Countermeasure Systems (International) v EUIPO, C‑340/17 P, EU:C:2018:965, paragraph 39).

208    As regards whether the second complaint is admissible, suffice it to state that, by that complaint, the Commission is raising a question of law in so far as it criticises the General Court for having, erroneously, compared the price increase to which the proposed concentration could give rise with those identified in the Irish and German cases in which the Commission authorised the concentrations in question subject to compliance with certain conditions. That complaint is therefore admissible.

209    As regards whether the first part of the fourth plea is effective, it is true that the General Court held, in paragraph 268 of the judgment under appeal, that the quantitative analysis is not decisive evidence demonstrating that there may be a significant impediment to effective competition. However, it did not find that that analysis was, in principle, lacking probative value. The General Court found that that analysis was not sufficient to demonstrate a significant impediment to effective competition.

210    In order to come to the finding in paragraph 282 of the judgment under appeal that the Commission had not demonstrated that prices would increase significantly following the proposed concentration, the General Court, in the first place, found in paragraph 273 of that judgment, that, in the present case, the price increase to which that concentration could give rise was [confidential]% and that that figure had not been disputed by the Commission. In the second place, in order to ascertain whether that increase can be classified as significant, the General Court compared it with the predicted price increases in the Irish and German cases, which were 6.6% and 9.5% respectively. The General Court observed that, in those cases, the Commission authorised the concentrations concerned subject to compliance with certain conditions.

211    Therefore, it must be held that the Commission is entitled to criticise the General Court, first, for having distorted its arguments concerning the exact value of the price increase to which the proposed concentration could give rise and, second, for having erroneously compared the present case with previous Commission decisions in other merger cases. Those complaints cannot be rejected on the basis that they are ineffective since, as the Advocate General observed in point 141 of her Opinion, each of those arguments could affect the General Court’s finding in paragraph 282 of the judgment under appeal. It is therefore necessary to reject CK Telecoms’ argument that the first part of the fourth ground of appeal is ineffective and to examine the substance of that part.

212    In that regard, as regards the first complaint in that part, alleging that, in paragraph 273 of the judgment under appeal, the General Court distorted the Commission’s arguments in paragraph 157 of its defence and in paragraph 61 of its rejoinder, it must be recalled that an appellant alleging distortion of its own arguments must, under Article 256 TFEU, the first paragraph of Article 58 of the Statute of the Court of Justice of the European Union and Article 168(1)(d) of its Rules of Procedure, indicate precisely the arguments alleged to have been distorted and demonstrate the errors in the analysis which, in its view, resulted in the General Court making that distortion (see, to that effect, judgment of 1 July 2020, Knauf Gips v Commission, C‑407/08 P, EU:C:2010:389, paragraph 31 and the case-law cited).

213    In the present case, it is apparent from paragraph 273 of the judgment under appeal that the General Court found that ‘in the present case, the predicted price increase is, according to [CK Telecoms] – which is not contradicted on that point by the Commission – [confidential]%, whereas a predicted price increase of 6.6% in the Irish case and 9.5% in the German case did not prevent the Commission from authorising those concentrations subject to compliance with certain conditions’.

214    It is clear from paragraph 157 of the Commission’s defence that the Commission had in fact challenged at first instance the figure proposed by CK Telecoms and had argued that, in the present case, the price increase to which the proposed concentration could give rise was [confidential]%. That finding is also supported by paragraphs 159 and 160 of the defence and by paragraph 61 of the Commission’s rejoinder.

215    It is therefore apparent from the documents in the file that, in paragraph 273 of the judgment under appeal, the General Court distorted the Commission’s written pleadings at first instance.

216    The first complaint in the first part of the fourth ground of appeal must therefore be upheld.

217    As regards the second complaint in the first part of the fourth ground of appeal, alleging that the General Court erred in comparing the present case with the Irish and German cases and, accordingly, erred in holding, in paragraph 273 of the judgment under appeal, that the price increase to which the proposed concentration could give rise, of [confidential]%, was not significant since it was lower than the predicted price increases in the Irish and German cases, it should be stated, first, that that assessment by the General Court is founded, as is apparent from paragraph 215 of the present judgment, on the General Court’s distortion of the Commission’s defence concerning the exact value of that price increase.

218    Second, as the Advocate General stated, in essence, in point 147 of her Opinion, the Irish and German cases were not comparable to the present case in one essential respect, since, unlike in the present case, the parties to the concentrations at issue in those prior cases had offered commitments which were considered sufficient to remove the Commission’s competitive concerns.

219    In any event, as has been pointed out in paragraph 164 of the present judgment, the Commission’s practice in previous decisions does not serve itself as a legal framework for merger control and can give only an indication.

220    The General Court therefore erred in law when, in paragraph 273 of the judgment under appeal, it held that the price increase of [confidential]% to which the concentration could give rise was not significant since it was lower than the predicted price increases in the Irish and German cases.

221    It follows that the second complaint in the first part of the fourth ground of appeal must be upheld.

222    In the light of all the foregoing, the first part of the fourth ground of appeal must be upheld in its entirety.

 The second part

–       Arguments of the parties

223    By the second part of the fourth ground of appeal, the Commission submits that the General Court erred in holding, in paragraphs 277 to 279 of the judgment under appeal, that the Commission ought to have included the ‘standard’ efficiencies which are ‘specific to each concentration’ in its quantitative analysis.

224    The Commission states that, in accordance with recital 29 of Regulation No 139/2004, it is for the undertakings concerned to provide a description of each of the claimed efficiencies and supporting documents relating thereto.

225    Contrary to the General Court’s finding in paragraph 277 of the judgment under appeal, the EU legislature has not established a presumption that all concentrations necessarily give rise to efficiencies which ought systematically to be taken into consideration in the quantitative analysis carried out by the Commission. It follows, in essence, from paragraphs 77 to 87 of the Horizontal Merger Guidelines that efficiencies have to benefit consumers, be merger-specific and be verifiable.

226    In addition, the Commission takes the view that Regulation No 139/2004 does not distinguish between different types of efficiencies.

227    In any event, the Commission submits that, in its quantitative analysis, it took account of efficiencies which could fall within the concept of ‘standard efficiencies’, as adopted by the General Court in paragraph 277 of the judgment under appeal, and excluded them, on the ground that they were not capable of affecting the merged entity’s incentives to increase prices.

228    CK Telecoms contends, in the first place, that the Commission’s line of argument is ineffective, since the General Court’s conclusion that the quantitative analysis in the decision at issue was incorrect was not based exclusively on the finding that the Commission had not duly taken into account the efficiencies generated by the proposed concentration.

229    In the second place, CK Telecoms submits, first of all, that the Commission’s argument is based on a misreading of the judgment under appeal. The General Court considered, in essence, that the probative value of a quantitative analysis is reduced if it does not also take into account the countervailing factors, including efficiencies. CK Telecoms’ view is that the General Court concludes that the evidentiary value of the quantitative analysis would be increased if the Commission assumed a certain level of efficiencies that are likely to result from the merger.

230    Next, according to CK Telecoms, the General Court’s assessment is in line with the nature of the quantitative analysis, which was developed to measure both the restrictive effects and the pro-competitive effects of mergers. It is therefore necessary to take into account proven or assumed efficiencies.

231    In addition, Regulation No 139/2004 takes into account the fact that concentrations generally entail pro-competitive effects and anticompetitive effects. CK Telecoms argues that the General Court’s finding that the output of the Commission’s quantitative analysis is of limited evidentiary value because that analysis fails to take into account ‘standard’ efficiencies is therefore consistent with the principles underlying that regulation.

232    Lastly, CK Telecoms maintains that, given that the Horizontal Merger Guidelines do not prescribe how the Commission is to carry out its quantitative analysis, it is not possible to conclude that the General Court’s findings on the evidentiary value of that analysis contradict those guidelines.

–       Findings of the Court

233    As regards the effectiveness of the second part of the fourth ground of appeal, it is apparent, in essence, from paragraph 279 of the judgment under appeal that, according to the General Court, ‘standard’ efficiencies are ‘specific to each concentration’ and constitute ‘a component of a quantitative model designed to establish whether a concentration is capable of producing … restrictive effects’.

234    Accordingly, in view of the importance which the General Court attached to that category of efficiencies for the purposes of the quantitative analysis, it must be held that the Commission can reasonably criticise the General Court for having required it, in paragraphs 277 to 279 of the judgment under appeal, to include in that analysis the ‘standard’ efficiencies which, according to the General Court, are specific to each concentration.

235    CK Telecoms’ argument that the second part of the fourth ground of appeal is ineffective must therefore be rejected.

236    As regards the substance of that part of the fourth ground of appeal, it should be recalled that, in paragraph 277 of the judgment under appeal, the General Court found that any concentration leads to efficiencies, the extent of which will also depend on external competitive pressure. According to the General Court, those efficiencies result, inter alia, from the rationalisation and integration of production and distribution processes by the merged entity, which could lead that entity to lower its prices.

237    In paragraphs 278 and 279 of that judgment, the General Court drew a distinction between two types of efficiencies, namely (i) those referred to in the Horizontal Merger Guidelines, the existence of which must be demonstrated by the notifying party and which must be taken into account in the overall competitive appraisal of the concentration, in order to ascertain whether they are likely to counteract the restrictive effects of the concentration and (ii) those referred to in paragraph 277 of that judgment, which are specific to each concentration and which are ‘a component of a quantitative model designed to establish whether a concentration is capable of producing such restrictive effects’. As is apparent from paragraph 278 of the judgment under appeal, the General Court held, in essence, that the Commission is required, in its quantitative analysis, to take into account, of its own motion, the latter category of ‘standard’ efficiencies.

238    It is apparent from recital 29 of Regulation No 139/2004 that, in order to determine the impact of a concentration on competition in the internal market, account should be taken of likely efficiencies put forward by the undertakings concerned.

239    It is also apparent from Section 9 of Annex I to Regulation No 802/2004 that it is for the undertaking concerned to provide a description of each of those claimed efficiencies, together with supporting documents.

240    The criteria for taking such efficiencies into account are referred to in paragraphs 76 to 88 of the Horizontal Merger Guidelines.

241    Accordingly, it must be held, as the Advocate General stated in point 153 of her Opinion, that neither Regulation No 139/2004, nor Regulation No 802/2004, nor the Horizontal Merger Guidelines refer to a category of ‘standard’ efficiencies, such as that referred to in paragraphs 277 to 279 of the judgment under appeal, nor do they establish a presumption that all concentrations give rise to such efficiencies.

242    It is true that certain concentrations may give rise to efficiencies which are specific to them. However, that possibility in no way implies that all concentrations give rise to such efficiencies. In any event, it is for the notifying parties to demonstrate those efficiencies so that the Commission can take them into account in its review.

243    Furthermore, to acknowledge that all concentrations give rise to ‘standard’ efficiencies would amount to creating a presumption, and therefore a reversal of the burden of proof, in respect of a particular category of efficiencies, whereas, as is apparent from paragraphs 238 and 239 of the present judgment, that burden is borne by the undertakings.

244    Such a reversal of the burden of proof is capable of reducing the effectiveness of merger control and, therefore, of calling into question the practical effect of Article 2(2) and (3) of Regulation No 139/2004. The objective of the effective control of concentrations which that regulation pursues, as recalled in paragraph 106 of the present judgment, in particular the objective of avoiding, first, the prohibition of concentrations which would not pose a risk of anticompetitive effects and, second, the authorisation of concentrations which would prejudice effective competition, is guaranteed, inter alia, by the allocation of the burden of proof in the field of merger control which has been established by the EU legislature.

245    The reversal of the burden of proof entailed by acknowledging a presumption that all concentrations give rise to such efficiencies would prejudice that balance.

246    In those circumstances, it must be held that the General Court erred in law when it found, in paragraphs 277 to 279 of the judgment under appeal, that the Commission ought to have included the ‘standard’ efficiencies which are specific to all concentrations in its quantitative analysis.

247    In the light of all the foregoing, the second part of the fourth ground of appeal and, accordingly, the fourth ground of appeal in its entirety must also be upheld.

 The fifth ground of appeal

 Arguments of the parties

248    By its fifth ground of appeal, the Commission complains that the General Court did not analyse whether all the relevant factors supported the conclusion that the Commission had been able, in the present case, to establish that the proposed concentration would result in a significant impediment to effective competition. The General Court erroneously limited its examination to certain factors supporting the first theory of harm and whether, taken separately, those factors were sufficient to establish such an impediment. In so doing, the General Court distorted the decision at issue, substituted its economic assessment for that of the Commission, misapplied the relevant legal tests and infringed its obligation to state reasons.

249    The Commission submits, more specifically, that the General Court examined only four of the factors which supported the first theory of harm put forward in the decision at issue. More specifically, the General Court examined the size and evolution of market shares, Three’s classification as an ‘important competitive force’, the closeness of competition between Three and O2 and the quantitative analysis of the effects of the concentration.

250    In limiting its examination in that manner and in annulling the decision at issue on that basis alone, the General Court failed to assess whether those four factors, combined with the other factors and findings set out in the decision at issue, made it possible to conclude that the proposed concentration would give rise to a significant impediment to effective competition.

251    In paragraphs 149, 171 to 173, 249 and 268 of the judgment under appeal, the General Court examined those four factors separately in order to determine whether each of them was, in itself, sufficient to establish such an impediment. The Commission argues that it in no way considered in the decision at issue that each of those factors, taken separately, was sufficient to establish a significant impediment to effective competition.

252    It is also apparent from paragraph 26 of the Horizontal Merger Guidelines that, taken separately, the factors referred to in paragraphs 27 to 38 of those guidelines are not necessarily decisive.

253    CK Telecoms submits, first of all, that it is not for the General Court but rather for the Commission to carry out an overall assessment of all the relevant factors which may influence whether significant non-coordinated effects are likely to result from the merger. Accordingly, the fifth ground of appeal is inadmissible and ineffective, in particular because, by that ground of appeal, the Commission is essentially requesting that a finding be made that the General Court must fill the gaps in the decision at issue and re-examine the proposed concentration, which is not compatible with the scope of its judicial review.

254    Next, CK Telecoms submits that the General Court reviewed all relevant factors relating to the first theory of harm set out in the decision at issue. In that regard, it states that, in paragraph 139 of the judgment under appeal, the General Court was correct in finding that, at the hearing, the Commission specified that that first theory was based, in essence, on three factors, namely the fact that Three is an ‘important competitive force’, the closeness of competition between Three and O2 and the quantitative analysis of the effects of the proposed concentration on prices. According to CK Telecoms, it was therefore correct and logical for the General Court to focus its review on those factors.

255    Lastly, the General Court did not consider that each of the factors relating to the Commission’s first theory of harm, taken separately, had to be sufficient in order to establish a significant impediment to effective competition. The General Court considered that the Commission had not demonstrated that those factors were sufficient to conclude that the proposed concentration would give rise to such an impediment.

 Findings of the Court

256    As regards CK Telecoms’ argument that the fifth ground of appeal is inadmissible and ineffective, it must be observed that, by that ground of appeal, the Commission is raising a question of law, the answer to which is capable of affecting the substance of the General Court’s finding that the Commission has not been able to establish, to the requisite legal standard, the existence of a significant impediment to effective competition. By that ground of appeal, the Commission complains, in essence, that the General Court annulled the decision at issue without having carried out an overall analysis or weighing of all the relevant factors taken into account in the decision at issue, but merely examined certain factors supporting, in particular, the first theory of harm and whether they were sufficient for the purposes of that analysis.

257    It is therefore necessary to examine the substance of the fifth ground of appeal.

258    In that regard, it should be recalled that, as is apparent from Article 2(1)(b) of Regulation No 139/2004, in the context of its review of a concentration, the Commission must take into account the market position of the parties to that concentration and their economic and financial power, the alternatives available to suppliers and users, their access to supplies or markets, any legal or other barriers to entry, supply and demand trends for the relevant goods and services, the interests of the intermediate and ultimate consumers, and the development of technical and economic progress provided that it is to consumers’ advantage and does not form an obstacle to competition.

259    It should also be recalled that paragraphs 26 to 38 of the Horizontal Merger Guidelines list factors which may actually influence whether significant non-coordinated effects are likely to result from a merger.

260    Paragraph 26 of those guidelines states in that regard, correctly, that those factors, taken separately, are not necessarily decisive. In addition, not all of those factors need to be present for significant non-coordinated effects to be likely.

261    In that context, it must be found that those factors may, in principle, constitute evidence that a concentration would give rise to significant non-coordinated effects, which must be the subject of an overall assessment.

262    Accordingly, in order to be able to carry out an effective judicial review of Commission decisions declaring a concentration incompatible with the internal market, it is for the EU Courts, after examining the substance of the complaints made against the Commission’s assessment of the relevant factors and in the light of the outcome of those complaints, to assess whether all the relevant factors and evidence on which the Commission has relied and which may be regarded as established, including those which have not been disputed, are sufficient to demonstrate the existence of a significant impediment to effective competition. That overall assessment does not mean that the EU Courts are required to examine of their own motion the substance of the assessment of factors or other evidence which have not been challenged by the parties to the proceedings.

263    In the present case, as regards the first theory of harm put forward by the Commission, paragraphs 128 to 136 of the judgment under appeal contain a summary of the decision at issue.

264    In paragraphs 141 to 283 of the judgment under appeal, the General Court examined CK Telecoms’ arguments raised in the context of the first plea in law in the action at first instance and relating, in essence, to the factors which may influence whether significant non-coordinated effects are likely to result from a proposed merger, namely the market share analysis, Three’s classification as an ‘important competitive force’, the assessment of the closeness of competition between the parties to the proposed concentration and the quantitative analysis of the effects of that concentration on prices.

265    In paragraph 154 of the judgment under appeal, the General Court rejected the fourth part of the first plea in law in the action at first instance. As is apparent, in essence, from paragraph 152 of the judgment under appeal, the General Court found that, contrary to the applicant’s arguments at first instance, the Commission took the view, in the decision at issue, that the size and evolution of the market shares of Three and of O2 were a first indication of the important competitive constraint exerted by them, which would be eliminated by the proposed concentration.

266    By contrast, in paragraphs 176, 190, 198, 216, 226, 250 and 283 of the judgment under appeal, the General Court upheld certain complaints and parts of the first plea in law relating to Three’s classification an ‘important competitive force’, the assessment of the closeness of competition between Three and O2 and the quantitative analysis of the effects of the proposed concentration on prices.

267    Lastly, in paragraphs 284 to 291 of the judgment under appeal, the General Court examined and upheld the seventh part of the first plea in law in the action at first instance, in accordance with which the Commission, first, failed to make an overall assessment of the existence of non-coordinated effects and, second, failed to state on what basis it concluded that the alleged impediments to competition brought about by the proposed concentration were important.

268    As regards whether the Commission, in the present case, made an overall assessment of the existence of non-coordinated effects, the General Court found, in paragraph 287 of the judgment under appeal, that, in the decision at issue, the Commission did carry out such an assessment. The General Court stated that, in order to demonstrate the existence of non-coordinated effects on the retail market, the Commission examined various relevant factors in turn.

269    However, the General Court did not itself examine whether – in the light of (i) the outcome of its examination of CK Telecoms’ arguments at first instance concerning some of the relevant factors and (ii) the other relevant factors and findings which formed part of the Commission’s overall analysis, which, since they were not challenged, could therefore be regarded as having been established, such as, for example, the specific assessment of the competitive constraint exerted by O2, the likely conduct of the entity resulting from the proposed concentration and the assessment of the competitive position both of mobile network operators and mobile virtual network operators set out in recitals 778 to 1174 of the decision at issue – it could be considered that the Commission had demonstrated to the requisite legal standard the existence of a significant impediment to effective competition.

270    In those circumstances, it must be held that, by failing to carry out, following its examination of the substance of the factors and findings contested by CK Telecoms at first instance and in the light of the result of that examination, an overall assessment of the relevant factors and findings, in order to ascertain whether the Commission had demonstrated the existence of a significant impediment to effective competition, the General Court erred in law.

271    The fifth ground of appeal must therefore be upheld.

 The sixth ground of appeal

272    The sixth ground of appeal consists of two parts. By the first part, the Commission complains that the General Court distorted the decision at issue by concluding, in paragraphs 358 to 361 of the judgment under appeal, that the Commission had failed to assess possible degradation of the quality of the merged entity’s network subsequent to the proposed concentration. By the second part of that ground of appeal, the Commission submits that the General Court raised, of its own motion, a complaint which did not appear in the sixth part of the third plea in law of the application at first instance.

 Whether the sixth ground of appeal is effective

–       Arguments of the parties

273    CK Telecoms submits that the sixth ground of appeal is ineffective because the Commission does not challenge the General Court’s central findings which led it to reject the Commission’s second theory of harm relating to network-sharing agreements.

274    First, in the context of the present appeal, the Commission has not challenged the findings in paragraphs 325, 330, 340, 344 and 346 to 348 of the judgment under appeal, by which the General Court held, in essence, that the Commission erred in concluding that a possible misalignment of the interests of the partners in a network-sharing agreement and the lasting disruption of the network-sharing agreements were likely, in themselves, to significantly impede effective competition, in accordance with a theory of harm based on non-coordinated effects.

275    Second, in its appeal, the Commission has not challenged the General Court’s analysis in paragraphs 362 to 397 of the judgment under appeal, concerning the effects of the concentration in question on BT/EE and Vodafone.

276    However, all those undisputed findings led the General Court to reject the second theory of harm.

277    The Commission contends that the sixth ground of appeal is effective.

–       Findings of the Court

278    In the first place, it should be recalled that, in paragraphs 325, 330, 340, 344 and 346 to 348 of the judgment under appeal, the General Court examined whether the lasting disruption to the proper functioning of the network-sharing agreements on account, in particular, of a possible misalignment of the interests of the partners to those agreements would, in itself, be likely to constitute a significant impediment to effective competition.

279    The Commission did not conclude that such an impediment existed exclusively on the basis of such misalignment of interests, since that misalignment of interests was only one of the factors taken into account in the decision at issue.

280    Accordingly, the fact that the Commission is not disputing the General Court’s finding that the misalignment of interests between the partners in the network-sharing agreements, as such, was insufficient to establish a significant impediment to effective competition cannot render ineffective the Commission’s sixth ground of appeal.

281    In the second place, as regards CK Telecoms’ argument that the sixth ground of appeal is ineffective on the ground that the Commission did not dispute the General Court’s analysis in paragraphs 362 to 397 of the judgment under appeal, relating to the effects of the proposed concentration on BT/EE and Vodafone, it should be noted, as is apparent, in particular, from paragraph 361 of that judgment, that the General Court examined whether the Commission’s analysis concerning the effects of the concentration on BT/EE and Vodafone was particularly solid and convincing. The General Court considered it necessary to start that examination from the premiss, set out in paragraphs 358 to 361 of that judgment and challenged in the first part of the present ground of appeal, that the decision at issue did not include an analysis of ‘a degradation of the services offered by the merged entity or of the quality of its own network’.

282    In those circumstances, as stated, in essence, in point 181 of the Advocate General’s Opinion, since the General Court’s findings in paragraphs 358 to 361 of the judgment under appeal constitute the basis of the appraisal, in paragraphs 362 to 397 of that judgment, of the effects of the proposed concentration on BT/EE and Vodafone, the fact that the Commission does not contest directly that appraisal by the General Court cannot render the sixth ground of appeal ineffective.

283    CK Telecoms’ argument alleging that the sixth ground of appeal is ineffective must therefore be rejected and, consequently, the substance of that ground of appeal must be examined.

 The first part

–       Arguments of the parties

284    By the first part of the sixth ground of appeal, the Commission submits that, in finding, in paragraphs 358 to 361 of the judgment under appeal, that the Commission had failed to assess possible degradation of the quality of the network resulting from the proposed concentration, the General Court distorted the decision at issue and erroneously concluded that the second theory of harm had to be rejected.

285    In that regard, the Commission states that the likely reduction in the incentives of mobile network operators, including the merged entity, to invest in improving network quality on account of that concentration is a fundamental element of the analysis in the decision at issue.

286    In the first place, it is apparent from recitals 1293 to 1297 of the decision at issue that the Commission examined the main hypothesis of a likely reduction in the incentive of the merged entity to invest in improving the quality of its network compared with the pre-concentration situation.

287    In the second place, the Commission examined a number of possible scenarios, mainly based on network consolidation plans put forward by Three. First, it is apparent from recitals 1558 to 1562 of the decision at issue that the Commission examined the decrease in the merged entity’s incentives to invest in the context of [plan A]. Second, it is apparent from recitals 1732 to 1742 of that decision that the Commission examined, in the context of [plan B], a reduction in overall network investments due to the increased transparency over the investments undertaken by each mobile network operator, including the investments by the merged entity.

288    In that context, the Commission submits that it assessed the risk of reduction in the network quality of the merged entity concentration and the corresponding reduction in competitive pressure on other mobile network operators.

289    CK Telecoms contends that the General Court did not distort the content of the decision at issue and that it did not disregard the recitals of that decision to which the Commission refers.

290    That company argues that, in order to understand the Commission’s arguments, account must be taken of the structure of the second theory of harm.

291    In that regard, CK Telecoms observes that that theory of harm comprises two sub-theories relating to network-sharing agreements. The first concerns the possible reduction in competitive pressure exerted by the other competitors (BT/EE and/or Vodafone) on the entity resulting from the proposed concentration (Three), while the second sub-theory relates to the network-sharing situation resulting from that concentration, which would increase overall transparency and reduce industry-wide investments in network infrastructure.

292    The Commission examined those two sub-theories of harm by reference to the network consolidation plans submitted by CK Telecoms.

293    In that context, according to CK Telecoms, the recitals of the decision at issue to which the Commission refers and which, according to the Commission, include an analysis of the degradation of the network of the entity resulting from the proposed transaction, relate not to the first sub-theory of harm, but rather to the second.

294    Paragraphs 358 to 361 of the judgment under appeal form part of the General Court’s analysis of the first sub-theory of harm, relating to a reduction in competitive pressure exerted by the other competitors, namely BT/EE and/or Vodafone, on the merged entity.

295    Therefore, the General Court cannot be criticised for having failed to take account, in those paragraphs, of the recitals of the decision at issue to which the Commission refers and for having thereby distorted that decision.

296    In those circumstances, CK Telecoms states that the General Court examined and rejected the second sub-theory of harm, not in paragraphs 358 to 361 of the judgment under appeal, but rather in paragraphs 398 to 418 of that judgment and that it took into account precisely the recitals of the decision at issue to which the Commission refers in particular in paragraphs 400 to 403 of that judgment.

–       Findings of the Court

297    By the first part of the sixth ground of appeal, the Commission submits that, in finding in paragraphs 358 to 361 of the judgment under appeal that the Commission had failed to assess a possible degradation of the quality of the network of the entity resulting from the proposed concentration, the General Court distorted the decision at issue and concluded, erroneously, that the second theory of harm had to be rejected.

298    As a preliminary point, it should be recalled that, as is apparent from paragraph 292 of the judgment under appeal, during the administrative procedure, Three submitted two network consolidation plans, namely ‘[plan A]’ and ‘[plan B]’. The basis for those plans were the two network-sharing agreements referred to in paragraph 18 of the present judgment, namely (i) the MBNL agreement concluded between BT/EE and Three, and (ii) the Beacon agreement concluded between Vodafone and O2. By those agreements, those operators had consolidated their respective networks in order to be able to share roll-out costs while continuing to compete on the retail market. According to those plans, the entity resulting from the proposed concentration was not expected to maintain two separate networks in the long term, rather it was envisaged that a single consolidated network would be created.

299    In paragraph 295 of the judgment under appeal, the General Court stated that, in the context of the second theory of harm relating to network-sharing agreements, the Commission set out two sub-theories.

300    It is apparent from paragraph 298 of that judgment that the first sub-theory consists, in essence, in finding that, subsequent to the proposed concentration, there would be a reduction in the competitive pressure exerted by the other competitors (BT/EE and/or Vodafone) on the merged entity (Three).

301    As regards the second sub-theory, it is apparent from paragraph 299 of that judgment that that sub-theory consists, in essence, in the network-sharing situation resulting from the proposed concentration leading to a reduction in industry-wide investments in network infrastructure. In recital 1233 of the decision at issue, the Commission submits that the transaction might lead to a loss of synergies affecting the partners in the network-sharing agreements and allow opportunistic investment behaviour by the merged entity, thereby reducing industry-wide investments and, as a consequence, the level of effective competition which would have prevailed in the absence of the transaction.

302    In addition, it should be noted that, having drawn attention, in recitals 1235 to 1243 of the decision at issue, to the importance of an alignment of interests between the partners in a network-sharing agreement, the Commission examined, in recitals 1244 to 1784 of that decision, the network consolidation plans in the light of those two sub-theories of harm.

303    In recitals 1293 to 1297 of that decision, the Commission then examined the main assumption of a likely reduction in the incentive of the entity resulting from the proposed concentration to invest in improving the quality of its network compared with the situation prior to that concentration.

304    Possible market developments subsequent to the proposed concentration are set out in recitals 1368 to 1784 of the decision at issue, of which recitals 1391 to 1567 deal with the effects of [plan A] and recitals 1598 to 1749 deal with the effects of [plan B]. Accordingly, the Commission examined the effects of those plans, first of all, on BT/EE and in particular on the MBNL network, next, on Vodafone and in particular on the Beacon network and, lastly, on overall investment in the networks concerned.

305    In its analysis of the effect of those plans on overall investment in the mobile networks, the Commission noted, in particular, in recitals 1556 to 1562 and recitals 1732 to 1742 of the decision at issue, that increased investment transparency between mobile network operators could reduce their incentive to invest in the networks and could therefore have a significant negative impact on industry-wide investment in those networks.

306    In particular, on the one hand, in recitals 1559 to 1561 and 1734 of the decision at issue, the Commission found, in essence, that, as a result of that increased transparency, the entity resulting from the proposed concentration could be made aware of investments by BT/EE in technology for the benefit of the MBNL network and thus itself decide to implement such technology for the benefit of the Beacon network [confidential]. According to the decision at issue, Vodafone might become aware that the entity resulting from the proposed concentration intends to implement that technology and thus have an incentive to refrain from making such technological investments until that entity does so.

307    On the other hand, in recitals 1735 and 1736 of that decision, the Commission took the view that, under [plan B], the entity resulting from the proposed concentration could be informed of the investments planned by BT/EE or Vodafone and have an incentive to make similar investments, both in the east and in the west of the United Kingdom [confidential]. In recital 1737 of that decision, the Commission concluded that increased transparency would entail the risk that BT/EE and Vodafone would wait for the entity resulting from the proposed concentration to make such investments in the development of significant new technologies before making such investments themselves.

308    In that context, as the Advocate General noted, in essence, in point 189 of her Opinion, it must be held that the Commission carried out an analysis of the possible degradation of the quality of both the MBNL network and the Beacon network. In carrying out that analysis, the Commission started from the premiss, set out in recital 1275 of the decision at issue, that an alternative way of reducing the competitive pressure exerted by a partner to a network-sharing agreement is to degrade network quality by blocking or delaying network investments by another partner to that agreement. It follows that the Commission considered from the outset that the reduction in competitive pressure could consist, inter alia, in such a degradation by the entity resulting from the proposed concentration of the quality of its own network.

309    In those circumstances, it must be stated that it is apparent from the decision at issue that the Commission assessed the possible degradation of the quality of the network of the entity resulting from the proposed concentration.

310    Accordingly, by finding, in paragraphs 358 to 361 of the judgment under appeal, that the Commission had not made such an assessment, the General Court distorted that decision.

311    As the Advocate General stated in point 191 of her Opinion, that finding cannot be invalidated by CK Telecoms’ argument that, having regard to the structure of the decision at issue, the Commission assessed the effects of [plans A and B] on overall investment in the respective networks under two separate headings.

312    It is true that, since the Commission’s assessments of the effects of [plan A] and of [plan B] on overall investment in the respective networks were made in two sections of that decision, entitled ‘Effects of [plan A] on overall network investments’ and ‘Effects of [plan B] on overall network investments’ respectively, they may appear to be more closely linked to the second sub-theory of harm. In addition, paragraphs 358 to 361 of the judgment under appeal, which are contested by the Commission, set out general considerations of the General Court concerning the first sub-theory of harm, according to which a reduction in competitive pressure exerted on the merged entity’s competitors could be observed. However, in its analysis of the effects of the two network consolidation plans on BT/EE and Vodafone and on overall investment in those networks, the Commission drew no formal distinction based on the sub-theory advanced, but, on the contrary, cross-referenced the various relevant parts of the decision at issue.

313    In the light of the foregoing, the first part of the sixth ground of appeal must be upheld.

 The second part

–       Arguments of the parties

314    By the second part of its sixth ground of appeal, the Commission, while relying on a failure to state reasons, submits, in essence, that, in order to uphold, in paragraph 417 of the judgment under appeal, the sixth part of CK Telecoms’ third plea in law at first instance, the General Court examined of its own motion a question which was not raised by CK Telecoms and that, consequently, the reasoning in paragraphs 408 to 416 of the judgment under appeal does not correspond to CK Telecoms’ complaints made in the context of that part of the plea in law.

315    In that regard, the Commission points out that, by the sixth part of its third plea in law at first instance, CK Telecoms argued, first, that the Commission erred in law in classifying the possible reduction in overall investments resulting from increased transparency over investments between mobile network operators as a non-coordinated effect and, second, that the Commission did not take full account of the commitments submitted by CK Telecoms.

316    According to the Commission, the reasons set out in paragraphs 398 to 416 of the judgment under appeal do not make it possible to understand the reasons why the General Court held, in paragraph 417 of that judgment, that the Commission erred in law in classifying the possible reduction in overall investments resulting from increased transparency over investments between mobile network operators as an non-coordinated effect.

317    The Commission states that, in paragraphs 408 to 416 of that judgment, the General Court addressed of its own motion another question, which CK Telecoms had not raised at first instance, concerning whether the Commission failed to set out, in the decision at issue, the appropriate time frame within which it intended to demonstrate a significant impediment to effective competition.

318    In those circumstances, the Commission submits that the General Court’s reasoning set out in paragraphs 404 to 416 of the judgment under appeal does not correspond to the finding it made in paragraph 417 of the judgment under appeal. That judgment therefore contains no reasoning as to whether the Commission erred in classifying a possible reduction in overall investments resulting from increased transparency over investments between mobile network operators as a non-coordinated effect and whether it made manifest errors of assessment in its analysis of the impact of the concentration on industry-wide investments.

319    CK Telecoms contends that the General Court set out clear and detailed reasons which led it to reject the second sub-theory of harm, enabling the persons concerned to understand the grounds of the General Court’s decision, and enabling the Court of Justice to exercise its review.

320    In that regard, CK Telecoms submits, in the first place, that, in paragraph 408 of the judgment under appeal, the General Court held that the Commission had failed to set out the time period within which it considered that a significant impediment to effective competition would arise. In paragraph 415 of that judgment, the General Court found that the analysis of the effects of a concentration on an oligopolistic market in the telecommunications sector which requires long-term investment and where consumers are often tied by contracts over several years is a dynamic prospective analysis which requires account to be taken of any coordinated or unilateral effects over a relatively long period of time in the future.

321    In the second place, the General Court considered that the Commission also failed to establish which of the multiple scenarios for network consolidation envisaged in the decision at issue would be the most likely.

322    In that regard, in paragraphs 410 to 413 of the judgment under appeal, the General Court established that, whatever the network consolidation plan ultimately adopted by the parties to the proposed concentration, the entity resulting from that concentration would not maintain two separate networks in the long term. That entity would therefore concentrate in the long term on one of the two network-sharing agreements.

323    In those circumstances, CK Telecoms argues that the General Court found, correctly, that the second sub-theory of harm had to be rejected in so far as it was based on the assumption – contrary to the facts found by the General Court – of the long-term existence of two separate networks.

–       Findings of the Court

324    It follows from the rules governing the procedure before the EU Courts, in particular Article 21 of the Statute of the Court of Justice of the European Union and Article 76 and Article 84(1) of the Rules of Procedure of the General Court, that the dispute is in principle determined and circumscribed by the parties and that the EU Courts may not rule ultra petita (see, to that effect, judgment of 10 December 2013, Commission v Ireland and Others, C‑272/12 P, EU:C:2013:812, paragraph 27).

325    While certain pleas may, and indeed must, be raised by the courts of their own motion, such as the question whether a statement of reasons for the decision at issue is lacking or is inadequate, which falls within the scope of essential procedural requirements, a plea going to the substantive legality of that decision, which falls within the scope of infringement of the Treaties or of any rule of law relating to their application, within the meaning of Article 263 TFEU, can, by contrast, be examined by the EU Courts only if it is raised by the applicant (judgment of 10 December 2013, Commission v Ireland and Others, C‑272/12 P, EU:C:2013:812, paragraph 28).

326    In the present case, it must be held that, by the sixth part of its third plea at first instance, CK Telecoms had argued first, that the Commission erred in law by classifying the possible reduction in overall investments resulting from increased transparency over investments between mobile network operators as a non-coordinated effect and, second, that the Commission did not take full account of the commitments submitted by CK Telecoms.

327    In paragraphs 398 to 401 of the judgment under appeal, the General Court recalled, in essence, that sixth part of the third plea in law and the Commission’s arguments. In paragraphs 402 to 407 of that judgment, the General Court examined the recitals of the decision at issue relating to the possible reduction in overall network investments on account of the increased transparency of investments between mobile network operators which would result from the proposed concentration.

328    In that context, instead of examining whether the Commission’s classification of that possible reduction in investments as a non-coordinated effect was erroneous and whether the Commission failed to take full account of the commitments submitted by CK Telecoms, the General Court held, in paragraph 408 of the judgment under appeal, that, in the present case, it was faced with ‘a particular difficulty’ in relation to the judicial review which it had to carry out of the decision at issue, since the Commission failed to set out the appropriate time frame within which it intended to establish a significant impediment to effective competition.

329    In paragraph 410 of the judgment under appeal, the General Court found, in essence, that, in the decision at issue, the long term was not taken into consideration by the Commission as the appropriate time frame for assessing the effects of the proposed concentration.

330    In that regard, the General Court stated, in paragraph 415 of that judgment, that the analysis of the effects of a concentration on an oligopolistic market in the telecommunications sector which requires long-term investment and where consumers are often tied by contracts over several years is a dynamic prospective analysis which requires account to be taken of any coordinated or unilateral effects over a relatively long period of time in the future.

331    The General Court concluded, in essence, in paragraphs 416 and 417 of the judgment under appeal that, in view of the fact that the parties to the concentration would not maintain two separate networks in the long term, the Commission had erred in law by classifying the effect of increased transparency on overall network investments as a non-coordinated effect, ‘in so far as [the second sub-theory] is based on the [erroneous] assumption of the existence of two separate networks’.

332    As the Advocate General observed in point 200 of her Opinion, it must be noted that, in its pleadings at first instance, CK Telecoms did not criticise the Commission for failing to set out or analyse the appropriate time frame with respect to which that institution intended to establish the existence of non-coordinated effects and a significant impediment to effective competition.

333    It must therefore be held that, without examining the complaints put forward by CK Telecoms in the context of the plea in question, the General Court raised of its own motion the complaint alleging an absence of precision in the time frame and the analysis of the non-coordinated effects in the long term.

334    It is clear that that complaint cannot be classified as a plea involving a matter of public policy within the meaning of the case-law of the Court of Justice referred to in paragraph 325 of the present judgment.

335    Accordingly, since, in order to uphold, in paragraph 417 of the judgment under appeal, the sixth part of the third plea in law at first instance of CK Telecoms, the General Court raised of its own motion, in paragraphs 408 to 416 of the judgment under appeal, a complaint which cannot be classified as involving a matter of public policy and, consequently, the reasoning in those paragraphs does not correspond to CK Telecoms’ complaints made in the context of that part of that plea in law, it must be held that the General Court erred in law.

336    Therefore, the second part of the sixth ground of appeal is well founded and the sixth ground of appeal must therefore be upheld in its entirety.

337    In the light of all the foregoing and having regard to the breadth, nature and scope of the errors made by the General Court, identified in the present judgment, which affect the General Court’s reasoning as a whole, the judgment under appeal must be set aside.

 Referral of the case back to the General Court

338    In accordance with Article 61 of the Statute of the Court of Justice of the European Union, if the appeal is well founded, the Court of Justice is to quash the decision of the General Court. It may itself give final judgment in the matter, where the state of the proceedings so permits, or refer the case back to the General Court for judgment.

339    In the present case, it is apparent from paragraphs 291, 397, 417, 418, 454 and 455 of the judgment under appeal that, since it upheld the pleas in law in the action at first instance listed in paragraph 41 of the present judgment, the General Court annulled the decision at issue and held that there was no need to examine the sixth part of the first plea in law, alleging that the Commission erred in taking the view that the incentives of the entity resulting from the proposed concentration to compete would probably be lessened compared with those of Three and of O2 prior to that concentration. It also did not examine the second plea in law concerning the Commission’s assessment of the counterfactual scenario, on which it based its assessment of the retail and wholesale markets, or the second and seventh parts of the third plea in law, concerning, first, the development of the two existing network-sharing agreements in the counterfactual scenario and, second, the assessment of the network-sharing commitments. Nor did the General Court rule on the fourth, fifth and sixth parts of the fourth plea in law, concerning the Commission’s assessment that the entity resulting from the proposed concentration would have a lesser incentive to compete, the Commission’s assessment that that entity’s competitors would have had neither the ability nor the incentive to compete with it, and the Commission’s reliance on certain assertions made by third parties respectively. Finally, the General Court did not rule on the fifth plea in law in the action at first instance, by which CK Telecoms disputed the Commission’s assessment of some of its commitments.

340    The pleas which were not examined by the General Court involve examination of a number of factual and legal issues, based on evidence which, first, was not assessed by the General Court in the judgment under appeal and, second, was not debated before the Court of Justice. In addition, the nature and scope of the errors committed by the General Court, identified in the present judgment, are such that the examination of the pleas relied on at first instance, which is vitiated by those errors, requires the General Court, essentially, to carry out, a new analysis of those pleas, which is markedly different from that in the judgment under appeal.

341    In that context, it must be held that, in the present case, the Court of Justice does not have the necessary information in order to give final judgment on all the pleas in law put forward at first instance.

342    In those circumstances, the case must be referred back to the General Court and the costs reserved.

 Costs

343     Since the case has been referred back to the General Court, the costs must be reserved.

On those grounds, the Court (Grand Chamber) hereby:

1.      Sets aside the judgment of 28 May 2020, CK Telecoms UK Investments v Commission (T‑399/16, EU:T:2020:217);

2.      Refers the case back to the General Court of the European Union;

3.      Orders that the costs be reserved.

[Signatures]

*      Language of the case: English.

1      Confidential data omitted.

© European Union
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