Mark Weiss

Mark G. Weiss

Baker & McKenzie LLP


Mark Weiss is an associate in the Firm's North America Antitrust & Competition Practice Group. He is an experienced litigator and counselor with proficiency in antitrust litigation, cartel investigations, no-poach defense, and merger review. Mark has vigorously and tirelessly represented clients in a variety of industries including banking, defense contracting, aerospace, energy, electronics manufacturing, and healthcare.

Prior to joining Baker McKenzie, Mark worked at another global law firm with a focus on class-action antitrust litigation, including defending a global electronics manufacturer from price-fixing and collusion claims. Mark also defended a major global financial institution from antitrust collusion and boycott claims and a large government defense contractor from claims alleging illegal no-poach agreements.

Practice Focus

Mark’s practice focuses on a range of competition and antitrust matters including complex civil litigation, criminal cartel defense, antitrust merger review, and compliance counseling.

Representative Legal Matters

  • Counsel for Defendant in In re: Hard Disk Drive Suspension Assemblies Antitrust Litigation (MDL 2918) in the Northern District of California alleging price-fixing claims.

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

  • Counsel for Defendant in In re: Capacitors Antitrust Litigation in the Northern District of California alleging collusion and price-fixing. The client favorably settled with direct and indirect purchaser classes.

  • Counsel for Defendant in Hunter v. Booz Allen Hamilton in the Southern District of Ohio alleging use of illegal no-poach agreements to restrain the employment market for government intelligence services.

  • Counsel for Defendant in In re: Stock Loan Antitrust Litigation in the Southern District of New York alleging collusion and boycott claims in the stock lending market.

  • Counsel for Defendant in Knurr v. Orbital ATK in the Eastern District of Virginia alleging violations of the federal securities laws. The case settled favorably.

  • Counsel for Defendant in Orbital Sciences v. United Launch Alliance in the Eastern District of Virginia alleging exclusionary conduct claims. The case settled favorably.

  • Successfully represented companies in front of the FTC and DOJ to clear mergers or acquisitions in a number of industries including grocery retail, automotive parts manufacturing, pawn shops, and recreational vehicle manufacturing.


  • District of Columbia~United States (2014)
  • Virginia~United States (2013)
  • U.S. District Court, Eastern District of Virginia~United States (2014)
  • U.S. Court of Appeals, Fourth Circuit~United States (2018)


  • George Mason University School of Law (JD, magna cum laude) (2013)
  • Claremont McKenna College (BA Economics & Government) (2007)


  • English
  • Author, "The Seventh Circuit Shows Steely Resolve in Scrapping a Putative Class of Indirect Purchasers," American Bar Association, Cartel & Joint Conduct Review, Winter 2019

  • Co-author, "The Department of Defense's Role in Merger Review," CPI Antitrust Chronicle, April 2019

  • Co-author, "United States: Cartels," The Antitrust Review of the Americas 2019, Global Competition Review

  • Co-author, "The FTC's Consent Decree in the Staples/Essendant Deal Sets the Playing Field for the New Commission's Split on Antitrust Enforcement," The M&A Lawyer, Volume 23, Issue 3, March 2019