Unpacking the European Commission's draft new Merger Assessment Guidelines

On 30 April 2026, the European Commission published its long-awaited draft new Merger Assessment Guidelines for public consultation, paving the way for the first substantive revision of EU merger control guidance in over two decades. The Commission plans to finalise the guidelines, which once adopted will replace the 2004 Horizontal Merger Guidelines and 2008 Non-Horizontal Merger Guidelines, by the end of the year. 

The publication of the draft guidelines is the culmination of an ambitious review process launched by the Commission in May 2025. It aims to modernise the analytical framework for the assessment of mergers, to reflect current practice and market realities, and respond to growing political pressure to facilitate industrial consolidation and scale-enhancing mergers that can improve the competitiveness, resilience and strategic autonomy of the EU economy. 

That pressure stemmed largely from Mario Draghi's 2024 report on the future of European competitiveness, which warned that the EU was lagging behind in investment and innovation. The report argued for a reform of EU merger control and for greater consolidation, to enable EU firms to compete globally. This call for change was embraced by Commission President von der Leyen, and reflected in her Mission Letter to Competition Commissioner Teresa Ribera, which stressed the need to give "adequate weight" to innovation, resilience and efficiency concerns when assessing mergers.

In the press, this generated anticipation of a material relaxation of EU merger control, in pursuit of greater scale and global competitiveness. The draft, however, is more nuanced – deftly seeking to accommodate the call for change, whilst not losing sight of the need to preserve open and effective competition in the EU’s internal market.

Summary of key changes

The draft represents a significant modernisation of the Commission's analytical toolkit, both structurally and substantively.

Focus on anticompetitive effects

The fundamental underpinning of the assessment framework remains the same. The SIEC test is unchanged, and the Commission will continue primarily to assess whether merging parties exert competitive constraints on each other that would be eliminated by a merger, and/or if competitors would be foreclosed from relevant markets. 

However, the new guidelines incorporate material additions and modifications to the Commission’s analytical framework. These include the following.

• A diminished role for structural indicators. Market shares are classified into tiers, and as in the old guidelines, guidance is given on the use of HHI² levels and deltas to identify market power.  However, the Commission appears to accord these indicators less probative value. The guidelines explore at length how market shares may not reflect firms’ market power. And the Commission’s choice of wording suggests that the structural soft safe harbours, which apply to mergers where market shares or HHI levels/deltas remain below certain values, have been softened further. The soft safe harbour for vertical and/or conglomerate mergers involving market shares below 30% has also been removed.
• A deeper analysis of the counterfactual. This is consistent with the greater focus on dynamic competition. The Commission may pay particularly close attention to whether the acquisition target may have been sold to an alternative purchaser in the absence of the merger, which could result in a concentrative merger being assessed against a counterfactual involving no, or only limited, market overlaps. Such a counterfactual could be less favourable than the pre-merger market conditions, e.g. if evidence indicates that the acquired business would have become a more powerful or closer competitor in the absence of the merger.
• New theories of harm and risk factors, including the following.
  • Entrenchment of a dominant position. This theory of harm (used in Booking/eTraveli) arises where one of the merging parties has a dominant position that would become less contestable as a result of a merger, regardless of the future conduct of the parties, such as where an acquisition would reinforce barriers to entry or expansion in the market. The guidelines elevate entrenchment to a standalone theory of harm and explain the Commission's approach, but also raise some questions. For example, does the theory imply that dominant platforms cannot improve their ecosystems (e.g. to create a more attractive one-stop-shop solution, with greater consumer appeal) by acquiring businesses in neighbouring fields, if this is likely to make it more difficult for other market players to retain and/or win new customers? And by taking entrenchment outside the usual vertical/foreclosure framework, are key elements of the analysis – particularly the need to demonstrate exclusionary effects – being sidestepped?
  • Minority shareholdings. The guidelines flag how non-controlling minority shareholdings and common institutional ownership can act as sources of competitive harm or amplify anticompetitive effects.
  • Portfolio effects. Increases of market power over a “portfolio” of products that are neither substitutes nor complements are now identified as a standalone theory of harm. This is distinct from tying or bundling in conglomerate mergers, and need not involve foreclosure.
  • Labour market effects. For the first time, the Commission has stated that adverse impacts on purchasing markets for supply of labour may amount to an SIEC. Even in the absence of an adverse effect in downstream product markets, an SIEC may arise where a loss of competition for labour leads to lower wages or worse working conditions. However, it remains unclear how the Commission will analyse such effects in practice, and how this will be incorporated into the notification process.
     
• An updated, more holistic approach to foreclosure. The guidelines maintain the tripartite approach to assessing foreclosure effects – separately assessing the parties’ ability and incentive to engage in foreclosure strategies, before considering anticompetitive effects. But they place significantly less emphasis on the relationship between the parties (indeed, foreclosure can occur even in the absence of a vertical link between the parties) and the level at which any foreclosure effects occur. Input foreclosure, customer foreclosure and tying/bundling are examined together in the guidelines, rather than separately. Additionally, the range of foreclosure strategies has been expanded, to include not just cutting off access to or raising the cost of inputs, but also degrading interoperability between products (as in Google/Fitbit) and post-sales services, impeding rivals’ pipeline products, and giving preferential access to one’s own downstream products.

Focus on efficiencies

The guidelines genuinely acknowledge that mergers can deliver efficiency benefits. And in the assessment of efficiencies the Commission will be giving weight to the key strategic and political objectives of the EU, including scale, global competitiveness, supply chain resilience, and sustainability – in so far as these are potential benefits that could result from certain mergers.

As noted above, efficiencies are introduced early in the document, in an attempt to place them on an equal footing with theories of harm. They are also stated to be subject to the same evidential standard as anticompetitive effects. 

However, the analytical framework for the assessment of efficiencies remains unchanged. Any claimed efficiencies must: 

• be verifiable – i.e. supported by credible evidence;
• be merger-specific – i.e. unlikely to be achievable by less anticompetitive alternatives;
• benefit consumers – and the consumers that benefit must be substantially the same as those harmed by any SIEC. This means one cannot trade off harm in one market against benefits in another market, unless there is a sufficient customer overlap between those markets. But the guidelines do recognise that customers may place a value on characteristics, such as sustainability, that have wider societal benefits rather than affecting the “use value” of the product. 

Furthermore, the guidelines note that claimed efficiencies that arise only in the longer term will carry less weight, particularly if they depend on speculative future developments. This complex balancing of asymmetric benefits and harm – e.g. more innovation in the long term, versus higher prices in the short term – involves potentially difficult trade-offs and gives the Commission considerable discretion. Whether parties will ever be able to reach a position where they have sufficient comfort as to their ability to overcome an SIEC finding remains to be seen. Likewise, it remains to be seen how theory will translate into practice, and if the Commission will genuinely apply a symmetrical evidential standard to the assessment of anticompetitive effects and efficiencies, by subjecting potential theories of harm to the same analytical rigour and level of scrutiny as efficiencies claims, and vice-versa. 

Public interest interventions

The Commission is proposing to include a new section in the guidelines dealing with the ability of Member States to invoke Article 21(4) EUMR to prohibit or impose conditions on transactions on public interest grounds. It seems the aim here is to prevent illegitimate use of this provision – responding to recent concerns about its use by certain governments (including in Italy). 

Member State measures must be genuine, proportionate and non-discriminatory. And Article 21(4) should not be used to prevent consolidation among EU firms, thereby thwarting single market integration. The draft also addresses interaction with other EU regulations (including the EU FDI Regulation): Member State measures that are in line with Commission decisions or opinions under such regulations will be deemed acceptable, reducing the scope for independent Member State intervention in areas already subject to EU-level measures. 

Practical implications

The draft guidelines reflect the direction of travel for merger assessment in recent years: analysis is becoming more complex and open-ended, with a wider range of factors to consider – potentially creating more grounds for intervention. The guidelines seek to encapsulate this approach, by moving away from strict horizontal/vertical categorisation, and reflecting how markets have evolved.

The practical consequence of this is that merger assessment is unlikely to become more predictable. But while the Commission gives itself more leeway to intervene, this is counterbalanced by a genuine shift in how it approaches merger benefits. Parties will have a greater opportunity to justify transactions on efficiency grounds, even if the evidential standard remains high, the burden of proof is on the parties, and the Commission's broad discretion means there is limited certainty as to outcomes. 

In practice, merger parties should therefore:

• think about and document potential merger efficiencies early. The Commission is clear that internal documents and external reports prepared before the conclusion of the merger agreement will carry significantly more weight;
• present merger benefits upfront, even in less problematic cases. Doing so may influence the Commission's approach to assessing theories of harm (assuming the efficiencies are real) and avoid an SIEC finding altogether;
• discuss efficiencies early. The Commission has signalled a willingness to engage in "efficiency talks" during pre-notification; and
• map new risk factors. Consider, at an early stage: (i) the likely weight that will be attached during the review process to traditional metrics (such as market shares) versus other factors; (ii) whether there is a risk of new theories of harm being tested, such as entrenchment, portfolio effects, labour market effects, or minority shareholdings; and (iii) what evidence will convince the Commission to dismiss potential concerns early on in its assessment, or – from a complainant’s perspective – investigate and endorse these concerns.