Mark Hamer

Baker & McKenzie LLP


Mark H. Hamer is Chair of the Firm's North America Antitrust & Competition Practice Group. Mark has over 25 years of wide-ranging litigation experience, including first-chair roles in jury trials, bench trials and arbitration proceedings. His primary focus is antitrust litigation.

Before joining Baker McKenzie, Mark was a successful federal prosecutor in the Antitrust Division of the US Department of Justice. He was involved in some of the DOJ's highest-profile antitrust trials. Before joining the DOJ, Mark was a partner at another global law firm where he handled complex multidistrict antitrust class actions in courts across the nation.

Practice Focus

Mark's practice focuses on antitrust litigation, both private and public. He assists clients in the defense of merger challenges, class actions, and civil and criminal investigations. He helps clients navigate federal and state regulatory inquiries, enforcement actions, complex merger clearance matters and multidistrict antitrust class actions.

As an experienced antitrust counsel, Mark also regularly provides antitrust advice on a broad range of non-litigation matters, including antitrust deal support, merger clearance strategy, sales and distribution advice, and antitrust compliance.

Mark is seasoned in a diverse array of industries, including payments, financial services, energy, rail and truck systems, computer hardware and software, consumer products, movie theaters, satellite broadcasting and insurance.

Representative Legal Matters

  • Served as lead US antitrust counsel for multinational filtration company in USD 4.3 billion sale to competitor.

Prior to joining the Firm, Mark handled the following matters:

  • Served as DOJ trial counsel in a two-month antitrust trial concerning credit card anti-steering rules, affecting over USD 50 billion in commerce.
  • Served as DOJ trial counsel in the challenge to a multinational manufacturer's USD 3 billion acquisition in the home appliances industry.
  • Served as DOJ trial counsel in the enforcement action to enjoin the merger of the nation's top two cinema advertising networks.
  • Served as trial counsel in a 2009 intellectual property and antitrust dispute in Silicon Valley concerning Blu-ray chip technology.
  • Represented the nation's largest manufacturer of packaged ice in multidistrict antitrust litigation and government investigations.
  • Represented a major satellite broadcaster in antitrust, intellectual property and unfair competition litigation.
  • Represented a Static Random Access Memory manufacturer in multidistrict antitrust class actions.
  • Represented a major power reseller in antitrust class actions and government investigations relating to the California energy crisis.
  • Represented a natural gas trading company in antitrust class actions and government investigations concerning natural gas price reporting.

Professional Honors

  • US Attorney General's Distinguished Service Award, 2015
  • US DOJ Antitrust Division Team Award of Distinction (2 awards), 2015
  • US DOJ Antitrust Division Award of Distinction for Individual Achievement, 2011


  • District of Columbia~United States (2017)
  • California~United States (1991)


  • University of Virginia School of Law (J.D.) (1991)
  • University of Virginia (B.A. with High Distinction) (1988)


  • English