September Antitrust and Competition Bulletin: Top-of-Mind Global Antitrust Issues

Welcome to this edition of the Sidley Antitrust and Competition Bulletin — thoughts on topics that are top of mind for Sidley’s global Antitrust and Competition team and why they may matter to you.

• The European Commission adopts EU Guidelines on exclusionary abuses of dominance.
• The California legislature passes an expansion of the Cartwright Act that awaits Gov. Newsom’s signature.
• FTC Chairman Ferguson calls for greater use of behavioral remedies in vertical mergers.
• The EU General Court upholds the European Commission’s prohibition of Booking’s acquisition of Etraveli.
• The European Commission publishes an Economic Study on Dynamic Effects of Mergers.

Read more on how this news can affect your business below....

---

EC adopts first Guidelines on exclusionary abuse: On September 3, the European Commission (EC) adopted its first guidelines on abusive exclusionary conduct by dominant companies (Guidelines), replacing its prior guidance on enforcement priorities. The Guidelines set out the EC’s intentions and provide a (nonbinding) reference point for European national competition authorities and courts, promoting consistent enforcement across the EU. The publication of the Guidelines is the culmination a three-year process that included extensive stakeholder consultation. The final Guidelines move away from the rigid presumption-based structure of the widely criticized 2024 draft in favor of a more flexible conduct-specific evidentiary framework.

Why it matters: The Guidelines consolidate an extensive body of EU case law, giving companies a clearer picture of how the EC will assess dominance and common commercial practices (e.g., exclusive dealing, rebates, bundling). Under this framework, the more likely conduct is to distort competition, the less evidence the EC needs to establish an abuse, shifting the burden onto companies to justify their practices. The Guidelines also reinstate a “soft safe harbor”: Companies with market shares below 40% are generally unlikely to be found dominant. For dominant or near-dominant companies, this raises the stakes of getting commercial strategy right from the outset.

---

California legislature sends antitrust bill to Gov. Newsom: On August 31, both chambers of the California legislature passed California Assembly Bill 1776 and have since provided it to Democratic Gov. Gavin Newsom for signature. If signed (or if Gov. Newsom elects to take no action by September 30 and thus lets the bill become law without his signature), the bill would amend the Cartwright Act to permit the California Attorney General or a California district attorney to prosecute claims against individual businesses for monopolization and monopsonization.

Why it matters: The bill constitutes a stark expansion of the Cartwright Act — which otherwise prohibits concerted action among multiple firms. Indeed, the amended act would provide California prosecutors with a new mechanism to regulate potentially anticompetitive conduct of individual firms instead of being forced to rely on actions for concerted conduct or distinct laws that do not as directly apply to antitrust enforcement. This, of course, increases the potential for additional antitrust enforcement actions in California.

---

FTC Chairman Ferguson calls for greater use of behavioral remedies in vertical mergers: On September 5, Federal Trade Commission (FTC) Chairman Andrew Ferguson addressed the International Bar Association’s 30th Annual Competition Conference in Florence, Italy, urging a “prudent” approach to vertical mergers that avoids both blocking them outright, on the one hand, and unconditional clearance on the other. In his words, “A settlement with appropriately structured behavioral remedies is sometimes the best approach to vertical-merger problems.” Indeed, Ferguson noted that the agencies have won only one of five litigated vertical-merger challenges since 2017.

To that end, while cautioning that “[a]ny prudent approach to antitrust-remedy design must consider the facts of each individual case,” Ferguson advocated openness to remedies that, among other things, “undercut incentives for the merged firm to shirk compliance” and “aid in the detection of noncompliance.” He then named options to achieve those ends, including requiring merged firms to arbitrate unresolved contractual disputes with new customers and requiring supplier-switching assistance where the merged firm dominates or new entrants need time to reach scale.

Why it matters: Ferguson’s remarks reflect his view of how to regulate vertical mergers and, importantly, indicate an openness to considering idiosyncratic behavioral remedies so long as they protect competition and to promote the collective benefits generated by a competitive marketplace. Just as importantly, his reference to the fact that antitrust agencies have prevailed in only one of the five vertical-merger challenges they have litigated since 2017 may also suggest his reduced willingness to litigate such actions through trial.

---

EU General Court upholds the EC merger prohibition: On September 9, the General Court of the European Union (GC) dismissed a challenge by Booking Holdings (Booking) to the EC’s 2023 prohibition of its €1.6 billion acquisition of Etraveli Group. The EC had found that the acquisition would have strengthened a dominant position in online travel agency services for hotels. According to the EC, the acquisition would have given Booking rapid access to flight data, enabling it to cross-sell hotel rooms as part of its “connected trip” strategy, thereby raising barriers to entry and expansion for rivals. The GC held that the EC’s 2008 Guidelines on the assessment of nonhorizontal mergers did not prevent the EC from addressing new forms of competitive harm or from relying on “reverse leveraging” (i.e., where a nondominant position in one market is used to reinforce an existing dominant position in another market). The GC rejected Booking’s argument that cross-selling and one-stop-shop convenience would amount to “competition on the merits,” holding instead that a concentration must be assessed by reference to its effects on the structure of competition. Booking has said that it disagrees with the outcome and is considering an appeal to the Court of Justice.

Why it matters: The judgment comes as the EC finalizes its review of its Merger Guidelines, with the new Draft Merger Guidelines expressly identifying “entrenchment of a dominant position” as a distinct theory of harm. Companies with strong positions in concentrated markets should expect more interest where the target provides strategically important access to customers, data, technology, or other capabilities that could reinforce the acquirer’s core position even if there is a small market share increment or limited overlap. For further information, see our Sidley Update EU General Court Upholds Booking/Etraveli Prohibition: Key Takeaways for Dealmakers.

---

EC publishes Economic Study on Dynamic Effects of Mergers: On September 11, a dedicated economic workshop took place to present the results of the EC Economic Study on Dynamic Effects of Mergers, published on August 24. “Dynamic effects” refers broadly to a merger’s impact on future product market competition, including on investment, innovation, entry, and prices, as distinct from a merger’s effects on current markets.

Why it matters: This study provides a structured framework for assessing both anticompetitive and procompetitive dynamic effects and informs the EC’s review of its Merger Guidelines, which are expected to be adopted before the end of 2026. Notably, the study concludes that greater market power in future product markets does not itself justify an “innovation defense.” It also warns that acquisitions of nascent competitors may suppress future competition even in the absence of current product market overlaps and expressly identifies the entrenchment of an incumbent with significant market power as a distinct dynamic concern. The study also includes sector-specific analyses of biopharmaceuticals, quantum computing and clean technologies, selected for their strategic importance and innovation dynamics.

• On Tuesday, October 6, 2026, Sidley will host an exclusive roundtable discussion: Who’s Afraid of Little Old SIEC? Featuring special guest Eline Vanhollebeke, Policy Officer in Unit A2, Mergers Case Support and Policy, DG COMP, European Commission and moderated by Sidley managing associate Iva Todorova, this discussion will consider the implications of recent judgments and other developments shaping EU merger control. To learn more or register, please contact us at brevents@sidley.com.