Booking/Etraveli: EU General Court Upholds Commission’s new Template for Digital Merger Control

Introduction

The EU General Court’s (the "Court") judgment in Booking/Etraveli marks a watershed moment for digital merger control in Europe. On 9 September 2026, the Court upheld one of the European Commission’s (the "Commission”) most noteworthy recent merger prohibitions, validating an approach that does not require material market share increments or horizontal overlaps to prohibit a deal. The ruling lands in a broader context of regulatory change: the Commission has simultaneously adopted its first comprehensive guidelines on exclusionary abuses of dominance and published draft merger guidelines that promise a more receptive approach to pro-competitive consolidation. The Article 102 Guidelines and draft Merger Guidelines provide the framework in which Booking/Etraveli will now be applied – but it is the judgment itself that sets the template. For dealmakers and large firms active in digital markets, the result is a landscape of heightened risk but also greater opportunity for those who can demonstrate genuine competitive benefits and real efficiencies.

This briefing examines the Booking/Etraveli judgment and its implications for conglomerate mergers in platform markets, placing the ruling in the context of two related regulatory developments: the new Article 102 Guidelines on exclusionary conduct by dominant undertakings, and the draft Merger Guidelines with their novel approach to efficiencies, innovation and scale.

1. The Booking/Etraveli judgment: A New Template for Ecosystem Enforcement

On 9 September 2026, the Court dismissed Booking Holdings’ challenge to the Commission’s prohibition of its proposed acquisition of eTraveli Group, a major European flight online travel agency. Booking was found to hold a 60-70% share of hotel online travel agency ("OTA") services; eTraveli was active principally in flight bookings, with no horizontal overlap between the businesses. The Commission's concern was that ownership of eTraveli would give Booking another route into hotel demand by adding flight-generated traffic, data and customer relationships to its hotel platform. Four points in particular stand out from the Court's judgment:

1. Guidelines are a framework, not a closed list. Booking argued that 'reverse leveraging' – using a non-dominant position in flights to reinforce dominance in hotels – departed from the 2008 Non-Horizontal Merger Guidelines. The Court held that those Guidelines lay down a general framework without limiting the Commission’s discretion, and predate concerns arising in digital markets. The direction of the leverage was immaterial to the Court; what matters is the effect on competition. It would be "contradictory", the Court reasoned, to allow intervention where leveraging strengthens a non-dominant position but not where it strengthens an already dominant one.
2. Perpetuating weak competition can itself be a significant impediment to effective competition ("SIEC"). Strengthening a dominant position does not automatically amount to a SIEC, and the Commission must show what makes it significant. But the Commission need not show that competition will become measurably worse. Where a market has strong network effects, high barriers to entry and a dominant firm far ahead of its rivals, a concentration that "consolidates and perpetuates" an already low level of competition can, in the Court’s view, suffice. Here, even a small increase in scale could chill rivals’ expansion, and the deal would capture one of the few customer acquisition channels Booking did not already dominate.
3. Numbers are not the whole case. The Court found material errors in the Commission’s calculation of the market-share increment but, nonetheless, upheld the prohibition, confirming that a decision may rest on qualitative evidence provided it is cogent, consistent and complete. Internal documents weighed heavily, and an economic analysis prepared during the Commission's merger review was given less weight than documents prepared in the ordinary course of business.
4. Efficiencies must be made, and made in time. Booking’s one-stop-shop argument was inadmissible because it had not been presented as an efficiency during the administrative procedure. Claimed benefits to flight customers could not offset harm in hotel OTAs because the two consumer groups were not “substantially the same”.

Booking has confirmed that it is considering an appeal to the Court of Justice. For now, however, the Commission has judicial support for an approach that it has already written into its draft Merger Guidelines – see further below. An appeal may yet test the boundaries of this analysis.

2. The New Article 102 Guidelines: Flexibility First

The final Article 102 Guidelines adopt a three-step test: establish whether the firm is dominant; assess whether its conduct "distorts effective competition"; and consider whether the conduct is objectively justified, including on efficiency grounds. They replace the 2008 Guidance but preserve a deliberately flexible framework for enforcement.

The “distorts effective competition” standard aligns the terminology with recent case law but largely retains the two-pronged test: conduct must depart from competition on the merits and be capable of producing exclusionary effects. A “sliding scale” replaces rigid categories: the more a type of conduct is generally likely to distort competition, the less case-specific evidence is required, and vice versa. The Commission will also articulate a “theory of harm” explaining the economic mechanism by which consumers may be harmed.

For dominant platforms, the Guidelines substantially expand the treatment of self-preferencing, distinguishing “offensive” and “defensive” leveraging and introducing an “expectation of neutrality or openness”, while confirming that there is no general rule against self-preferencing. The dominance analysis also addresses network effects, lock-in and data-driven advantages in digital ecosystems, including artificial intelligence – precisely the factors that featured prominently in the Court’s analysis in Booking/Etraveli. Dominance is unlikely below a 40% market share, while the 50% presumption becomes a firm rule save in exceptional circumstances. The presumption that exclusive dealing distorts competition is retained, and the as-efficient-competitor test is marginalised for non-pricing conduct.

The efficiency defence is significantly expanded to cover sustainability, out-of-market efficiencies and sunk investment considerations. The burden remains on the dominant firm, which must produce “a cogent and consistent body of evidence”. The Guidelines also leave open their relationship with the Digital Markets Act, and EVP Ribera has already signalled that the Commission will use the DMA to stop “big tech players from leveraging their dominance of the past into AI”.

Overall, the Guidelines largely restate the Commission’s reading of the case law, preserving flexibility to intervene rather than providing clear lines for self-assessment. Businesses will need to monitor how the Commission applies the framework in practice. Notably, some national authorities have already shown a willingness to use abuse of dominance rules as a backstop to merger control: in France, the Autorité de la concurrence has used behavioural proceedings to address competitive concerns arising from acquisitions that fell below merger notification thresholds, an approach that may become more common as authorities seek to close perceived enforcement gaps in digital markets.

3. Connecting the Dots: the draft Merger Guidelines

The draft Merger Guidelines carry these themes into merger control, while offering a more explicit route for parties to demonstrate the benefits of a transaction. They also give a clearer structure to the Commission's assessment of digital ecosystems and entrenched positions, building on lessons learnt from past cases. In many respects, the draft Guidelines codify the approach the Court validated in Booking/Etraveli – the judgment is not merely cited as a precedent but serves as the blueprint for the Commission’s theory of harm in digital conglomerate cases. It is worth noting, however, that Booking/Etraveli remains subject to potential appeal.

1. Entrenchment and ecosystems. The draft Guidelines combine horizontal and non-horizontal assessment in a single framework and identify eight theories of harm, including entrenchment of dominance, loss of innovation and loss of potential competition. Entrenchment may arise where a merging firm is dominant and the acquired assets are related to its core market and important for effective competition, such as a customer acquisition channel. The draft also states that there is “no hierarchy” between qualitative and quantitative evidence, so a compelling evidential picture need not depend on market shares alone.
2. Theory of benefit. Conversely, the draft says that “demonstrated efficiencies will play a key role” and invites parties to present a “theory of benefit” addressing dynamic efficiencies, scale, resilience and sustainability. An “innovation shield” safe harbour is proposed for certain acquisitions of small innovators, although it may be unavailable to designated gatekeepers in some scenarios. The familiar criteria remain: efficiencies must be verifiable, merger-specific and passed on to consumers, and must be advanced during the administrative procedure, as Booking/Etraveli shows.

Taken together, the instruments give the Commission more room to address entrenched positions, but require businesses to substantiate both harm and benefit through structured, evidence-heavy processes. The final Merger Guidelines are expected by the end of 2026 and will provide a more definitive framework for this balance. Similarly, the United Kingdom’s Competition and Markets Authority (the "CMA") has updated its merger assessment guidelines to provide more detail on how parties can raise rivalry-enhancing efficiencies as part of a merger assessment and is encouraging these issues to be flagged early in the review process without needing to concede that the transaction gives rise to competition concerns – a notably more open-door approach than in the past.

4. Key takeaways

Booking/Etraveli is the defining case of this period of regulatory change. Whether the Court of Justice ultimately upholds or narrows the Court’s analysis, the judgment has already reshaped the landscape for digital mergers in Europe – and dealmakers would be wise to plan accordingly:

1. Small increments no longer mean small risk. For dominant firms in markets with network effects, a minimal market share increment, the absence of horizontal overlap and a plausible consumer benefit narrative may not, without more, answer an entrenchment theory. Companies should assess whether a target feeds traffic, data or loyalty into their core business, or provides a customer acquisition channel rivals cannot readily reproduce.
2. Internal documents can be crucial evidence. References to “stickiness”, ecosystems or customer acquisition are likely to be read as evidence of competitive intent and effect, not throwaway lines to be explained away. Ensure deal rationales and commercial strategy documents are coherent and consistent with the pro-competitive rationale from the outset – the same discipline applies to conduct that may be assessed under Article 102.
3. Build the efficiency case early. Both sets of Guidelines expand the scope for efficiencies, but place the burden firmly on the parties. Identify efficiencies expressly as such, quantify them where possible and support them with ordinary-course documents, as early as possible in the process before the Commission completes its initial merger review.
4. Watch this space. The final Merger Guidelines are expected by the end of 2026, and any appeal in Booking/Etraveli may yet test the limits of the entrenchment theory. Digital platforms should also monitor enforcement on self-preferencing and the interaction with the DMA. In the UK, the CMA has signalled an emphasis on predictability within a settled substantive framework, with Chair Doug Gurr recently stressing that the fundamental 'substantial lessening of competition' test “has not changed” and that deals capable of being cleared “should be”. For transactions requiring multi-jurisdictional clearance, different regulatory approaches must be factored in, including risk profiles and timelines, bearing in mind that even below-threshold acquisitions may not escape scrutiny.

Mayer Brown's European Antitrust & Competition team comprises lawyers with a thorough knowledge of EU and UK merger laws and procedures as well as extensive experience of dealing with enforcers at national and EU level. Please contact us to discuss any of the issues summarised above in more detail.