Photo of Mark W. Ryan
Mark W. Ryan




Mark Ryan is a partner in Mayer Brown’s Washington DC office and the head of the firm’s Global Antitrust & Competition group. He is also a former Director of Litigation for the US Justice Department, Antitrust Division. Mark has extensive experience representing clients before the Federal Trade Commission and the Antitrust Division in connection with mergers and acquisitions. Mark is also one of the nation’s leading antitrust litigators. As the Antitrust Division Director of Litigation, Mark was responsible for overseeing and strengthening the Division’s litigation enforcement efforts. He worked regularly with staff lawyers and economists, as well as the senior leadership of the Division, to identify transactions and conduct that violated U.S. antitrust law and to assemble investigative and litigation teams. He also participated in litigation on behalf of the United States, including acting as lead trial lawyer in the e-books price-fixing litigation in the Southern District of New York and as a member of the trial team that successfully sued a major credit card issuer in the Eastern District of New York over anti-steering rules contained in merchant agreements. He also led the Division’s trial teams that challenged the InBev/Grupo Modelo and US Airways/American Airlines mergers. Both mergers were resolved by settlement after the United States filed suit. At the end of his tenure at the Justice Department, Mark was the lead trial lawyer in a challenge to the proposed merger of the two largest cinema advertising companies in the country, which the parties abandoned completely shortly before trial.

In addition to antitrust, Mark has represented boards of directors in shareholder derivative actions and in disputes with former senior executives. He has represented clients in trials of government and private lawsuits arising from bank failures and the collapse of the mortgage-backed securities market and handled numerous matters on behalf of major accounting firms.

On the eve of a trial, based on newly developed evidenced and other pre-trial efforts, he obtained the release from prison of an indigent criminal defendant who had served two years of a mandatory twenty year sentence.

Spoken Languages

  • English
Secrets of a Successful Trial Strategy


  • Recently acted as principal antitrust advisor in connection with strategic transactions in the coffee, waste disposal, marine supply and financial services industries.
  • Represented a pioneer pharmaceutical company in a Federal Trade Commission investigation and related litigation arising from alleged “pay for delay” patent settlements with generic manufacturers.
  • Represented the Chicago Board of Trade in its merger with Chicago Mercantile Exchange.
  • Represented a global medical equipment manufacturer in antitrust litigation arising from patent disputes.
  • Secured dismissal of monopoly claims against a leading publisher of technical journals.
  • Successfully defended a major oil company in a case alleging antitrust and fraud with respect to operations in Venezuela.
  • Represented an antitrust plaintiff in one of only a few monopolization claims in recent years in which a federal jury awarded large treble damages and in which the award was affirmed on appeal. The case involved an action by a small firm against an entrenched monopolist and the monopolist's efforts to block access to critical distribution channels. A judgment following a nine week trial was upheld by the US Court of Appeals for the Third Circuit sitting en banc.
  • Represented one of the nation's largest meatpackers in a successful jury trial and appeal of a lawsuit brought by a nationwide class of cattle ranchers.
  • Obtained a favorable jury verdict on behalf of a defendant in a Robinson-Patman Act case.
  • Represented one of the world's largest food ingredient companies in connection with government price-fixing investigations and resulting class action litigation in which the alleged damages totaled billions of dollars.
  • Represented a marine engine manufacturer in several acquisitions reviewed by the Federal Trade Commission, all concluding without objection, and in an extended FTC investigation of the manufacturer's rebate and discount policies that ended without any enforcement action.
  • Defeated the Office of the Comptroller of the Currency in a several week trial arising from the collapse of a bank brought about by a fraudulent subprime lending program. On appeal, the judgment was affirmed in a decision establishing important limitations on the OCC's ability to pursue administrative penalty actions against outside service providers; in related litigation established precedent limiting the scope of the "fraud on the market" doctrine in securities fraud class actions.


Duke University School of Law, JD

Syracuse University, BA, magna cum laude


  • District of Columbia
  • Maryland


  • US Supreme Court
  • US Court of Appeals for the District of Columbia Circuit
  • US Court of Appeals for the Third Circuit
  • US Court of Appeals for the Fourth Circuit
  • US Court of Appeals for the Eighth Circuit
  • US Court of Appeals for the Ninth Circuit
  • US Court of Appeals for the Eleventh Circuit
  • Maryland Court of Special Appeals


  • American Bar Association, Antitrust Section, Vice Chair, Agriculture and Food Committee (former)