Thomas Mueller


  • Chair, Antitrust and Competition Practice Group

Thomas Mueller is chair of WilmerHale's Antitrust and Competition Practice Group. He joined the firm in 1992.

Mr. Mueller's antitrust practice focuses on global cartel enforcement matters, as well as merger and other investigations with transatlantic implications. Having practiced both in Brussels and Washington, Mr. Mueller has insight into antitrust issues on both sides of the Atlantic and has helped steer clients through the difficulties and opportunities created by the closer cooperation between the US and EU authorities. Chambers describes him as "a figure of great stature within criminal and cartel investigation circles" and "a creative strategist, which makes him a perfect choice for this often complicated and rapidly moving area."

Professional Activities

Mr. Mueller is a member of the International Cartel Task Force in the American Bar Association's Section of Antitrust Law. He has also served as an adjunct professor at Georgetown University Law Center where he taught a course on comparative US and EU competition law.


  • Cartel Investigations and Litigation

    Mr. Mueller has extensive internal investigation and litigation experience. His experience in both the US and Europe has been helpful in developing strategies in responding to price-fixing allegations, often from multiple antitrust authorities around the world. He has successfully persuaded authorities to close investigations without taking enforcement action and has secured non-prosecution agreements and leniency protection for clients. A selection of recent cartel investigations and litigation matters include:

    • Representing DaVita in one of the first-ever criminal labor market allocation cases brought by the Department of Justice
    • Representing a Japanese capacitor manufacturer in the DOJ’s investigation of that industry
    • Representing the leading North Sea oil and gas producer in the FTC’s investigation related to the Brent Crude index
    • Representing a major natural gas company in DOJ and State AG investigations of leasing practices
    • Representing one of the world's largest auto parts manufacturers in resolving its criminal liability in the US
    • Representing a leading bearing manufacturer in the DOJ's investigation of that industry
    • Representing CSAV in the DOJ’s investigation of automobile ocean shipping
    • Representing a major European airline in investigations and litigation concerning the air cargo business
    • Representing JP Morgan Chase in the DOJ's investigation of the municipal derivatives market
    • Representing a major Japanese freight forwarder in DOJ investigations of the logistics industry
    • Representing Chi Mei Optoelectronics in the LCD investigation
    • Representing Odfjell ASA in the investigation by the US and EU of an alleged conspiracy among major chemical tanker companies
    • Representing a major private equity fund regarding the conduct of a portfolio company
    • Representing the lead euro dollar trader of a major US bank in the foreign exchange investigation
    • Representing a head of sales in an auto parts investigation
    • Representing the head of rates at a major bank in the LIBOR investigation
  • Merger Clearance

    Mr. Mueller has represented clients in numerous in-depth investigations of global transactions, including serving as lead EU counsel in the merger between America Online and Time Warner, at the time, the world's largest merger. He has obtained early conclusion of phase II cases before the European Commission, as well as the clearance by US and EU authorities of Tetra Laval's acquisition of Sidel—the only transaction to have been successfully appealed and then approved by the European Commission. 
  • Conduct Investigations and Counseling

    Mr. Mueller counsels clients in a wide variety of industries on issues of abuse of dominance and vertical and horizontal restrictions of competition. He has particular experience in the logistics, energy, manufacturing, finance and tech industries. 


  • Award Text

    Leading Lawyer for Antitrust and Competition Law

    Chambers Global


  • Award Text

    Among the Best Lawyers in America for Antitrust Law

    Best Lawyers in America®


  • Recognized for exceptional standing in the area of antitrust and competition law in the 2006–2024 editions of Chambers Global Guide.
  • Regularly recognized by Chambers USA Guide in Washington DC for antitrust law.
  • Regularly recognized by Chambers USA Guide nationwide for cartel law. 
  • Regularly recognized as a leading lawyer and named to the Hall of Fame for antitrust law in The Legal 500 United States.
  • Selected by his peers for inclusion in Best Lawyers in America in the areas of antitrust law and antitrust litigation (2010–2023).
  • Listed in the 2014 edition of Expert Guides as a leading economist in Washington DC in the area of Competition/Antitrust Law.
  • Named among "Washington's Best Lawyers" in antitrust in the 2013 issue of Washingtonian magazine.
  • Recognized as a leader in antitrust and competition law in the 2007–2012 editions Chambers Europe.
  • Listed in the 2006/2007, 2009/2010 and 2011/2012 editions of the PLC Cross-border Competition Handbook for competition/antitrust.
  • Recognized in the 2019 and 2005–2015 editions of Global Competition Review's Who's Who Legal, The International Who's Who of Competition Lawyers and Economists.
  • Selected to the 2011–2024 Washington DC Super Lawyers lists for his antitrust litigation practice.
  • In 2004, was subject of an in-depth profile as one of the top competition lawyers, featured in Global Competition Review's "40 under 40-The World's 40 Brightest Young Antitrust Lawyers and Economists."
  • Recognized by his peers as one of the world's leading antitrust and competition attorneys in Legal Media Group's The Best of the Best.
  • Visiting fellow, Max Planck Institute for Foreign and International Patent, Copyright, and Competition Law (Munich, Germany).
  • Named to the Lawdragon 500 Leading Litigators in America list.

Insights & News


  • Education

    • JD, Harvard Law School, 1990

      cum laude
    • BA, Williams College, 1987

      magna cum laude
  • Admissions

    • District of Columbia

    • Massachusetts

    • New York

    • Brussels (associate member)

  • Clerkships

    • The Hon. Walter J. Skinner, US District Court for the District of Massachusetts, 1990 - 1991



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