Consistently ranked among the top global antitrust practices, we bring credibility and teamwork to everything we do, from precedent-setting courtroom victories to deft handling of merger reviews by agencies around the world.

Our litigation abilities range from extricating clients early and efficiently to achieving groundbreaking results in high-exposure cases. And when it comes to shepherding transactions through global clearance processes, we are practice leaders. We routinely handle complex international mergers and obtain clearance in challenging situations.

We have a reputation for sophisticated, practical antitrust strategy that couples cutting-edge economic and doctrinal analyses with an adept reading of the regulatory and political environment, even under the tightest timeframes. And we are one of the few firms whose partners have tried—and won—cases for and against, the government.

With a team that includes veterans of the US Department of Justice’s Antitrust Division and the Federal Trade Commission, we offer clients an insider’s perspective, bolstered by our close partnerships with renowned economists and consultants.

Global Reach

  • Asia
    • We have a robust presence in Asia. In Japan, we submitted the first application under the Japanese Fair Trade Commission’s leniency system—within three months of its introduction in January 2006—and have a strong understanding of the recent revisions to Japan’s anti-monopoly laws. We have represented clients before the Korean Fair Trade Commission, and have guided clients in connection with competition policy matters in Taiwan, Singapore, and Hong Kong. We are active in China’s emerging competition law field, engaging in the dialog about implementing China’s new Antimonopoly Law and advising clients, in conjunction with local counsel, on compliance with Chinese competition rules.
  • Europe
    • Operating at the EU’s political and legislative center since 2004, our Brussels office focuses on EU and national competition law, as well as trade and sector regulation. Our work there has included a series of high-profile cases covering all main areas of EU competition law (Article 102, mergers, and cartel cases), achieving headline-grabbing results for our clients. We also have represented clients in proceedings before the EC and the EU, and have obtained either significant reductions in or voiding of fines at the EC Court of First Instance. Our lawyers are qualified in many EU member countries, are knowledgeable regarding many national laws and procedures, are fluent in various languages, and work closely with local authorities.
  • United States
    • Our US team offers the highest quality and breadth of knowledge in litigating antitrust cases in federal and state courts, representing companies before federal and state antitrust agencies, and counseling clients on the nuances of both federal and state antitrust laws. Our lawyers have extensive experience representing both companies and individuals facing criminal antitrust charges, litigating complex civil class actions, and obtaining regulatory approval of high-profile mergers. We provide ongoing counsel to clients facing complex and evolving business issues, including the design of antitrust-compliant licensing and distribution agreements and the development of legal strategies in precedent-setting price-fixing and monopolization cases.

AT&T and Time Warner

As lead trial counsel for both AT&T and Time Warner, O’Melveny defended the companies’ landmark US$85.4 billion merger against claims by the Department of Justice’s Antitrust Division that the transaction would harm competition and should be blocked. Read

Alaska Air Group

O’Melveny counseled Alaska Airlines on all aspects of its US$4 billion acquisition of Virgin America. Read

Bass Pro Group, L.L.C.

On July 3, 2017, the Federal Trade Commission officially closed its investigation into the proposed US$4.2 billion tie-up of two premier outdoor sporting goods retailers Bass Pro Group, L.L.C. and Cabela’s Incorporated, allowing the merger to close. Read

Broiler Chicken Criminal Antitrust Trial

In the largest criminal antitrust trial in recent memory—making history as the first antitrust criminal case to be tried three times, the final time resulting in a full acquittal—O’Melveny represented the former CEO of Pilgrim’s Pride, who was indicted by the US Department of Justice Antitrust Division along with nine other individuals for an alleged seven-year, industrywide conspiracy to fix prices and rig bids of broiler chicken products such as those sold to major fast food chains.



When Honeywell’s US$5.1 billion acquisition of the Elster Division of Melrose Industries plc drew scrutiny from antitrust authorities around the world, O’Melveny lawyers worldwide mobilized to defend the transaction before the Federal Trade Commission, China’s Ministry of Commerce, and the European Commission. Read


O’Melveny secured a major victory for Marriott when Judge Jane Boyle of the Northern District of Texas dismissed antitrust and consumer protection claims against Marriott, other hotel defendants, and a group of online travel company websites, including Expedia and Travelocity. Read

Samsung Electronics

O’Melveny has defended Samsung in a number of significant cartel matters over the last few years. Read

Samsung Electronics

O’Melveny defeated antitrust claims seeking more than US$1 billion in actual damages—US$3 billion in treble damages—in multidistrict litigation alleging Samsung was part of a conspiracy to fix prices of optical disk drives. Read

SK hynix Inc.

O’Melveny helped SK hynix Inc. (formerly Hynix Semiconductor) obtain a favorable settlement in long-running patent and antitrust litigation with Rambus, Inc. The 13-year dispute involved litigation on two continents, in multiple trial courts, multiple appellate proceedings and litigation before multiple agencies. Read

US Airways/American Airlines

When DOJ sued to enjoin US Airways’ multibillion dollar merger with American Airlines in August 2013, US Airways hired Rich Parker and O’Melveny to act as lead trial counsel. Read
    • Advanced Micro Devices, Inc.
    • American Airlines
    • Asiana Airlines
    • Bumble Bee Foods, LLC
    • Capital One Financial Corporation
    • Honeywell International
    • Marriott International Inc.
    • Norsk Hydro ASA
    • Precision Castparts Corporation
    • Quest Diagnostics Incorporated
    • Rohm Co., LTD and Rohm Semiconductor U.S.A. LLC
    • Samsung Electronics Co. Ltd.
    • SanDisk Corporation
    • SK Hynix Inc.