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About Mary Lehner

Mary is a Chambers ranked partner in our antitrust, competition and trade group based in Washington, DC.

Mary focuses her practice on representing clients before the Federal Trade Commission (FTC), the US Department of Justice (DOJ), and the State Attorneys General on the antitrust aspects of M&A, joint ventures, distribution and intellectual property arrangements, and other competitive conduct.

Before joining Freshfields, Mary served as an advisor to two FTC Chairs, providing counsel on antitrust investigations, enforcement actions, policy initiatives, public relations, and congressional strategies. Prior to her role in the Chairman’s office, Mary oversaw antitrust merger investigations as a lead attorney in the FTC’s Bureau of Competition.

Mary is an American Bar Association Fellow, an honorary distinction limited to one percent of lawyers licensed in each jurisdiction who have demonstrated outstanding dedication to the highest principles of the legal profession. Mary is also a leader in the American Bar Association Section of Antitrust Law, chairing the Corporate Counseling Committee. She frequently speaks on antitrust issues, most recently at numerous ABA and GCR panels and events.

Mary serves on the Steering Committee of GCR’s Women in Antitrust annual conference, has participated as a panelist in Women’s Competition Network and ABA Women in Deal Work events, and is a leader of  the Freshfields US Diversity & Inclusion Committee.

Recent work

  • Cargill and the buyer consortium on their $4.3bn take-private of Sanderson Farms and the concurrent combination of Sanderson Farms with Wayne Farms.
  • Saint-Gobain on its $2.3bn all-cash acquisition of GCP Applied Technologies.
  • Suzano on its $11bn acquisition of rival Brazilian pulp manufacturer, Fibria Celulose SA, which created the world’s largest hardwood pulp producer.
  • AstraZeneca on its successful $39bn acquisition of Alexion including securing unconditional clearance in more than 20 antitrust and foreign direct investment jurisdictions.
  • Starbucks Corporation on its $7.15bn global coffee alliance with Nestlé.
  • Rexam on the FTC’s Second Request review of its $6.9bn takeover by Ball Corporation, which brought together the world’s two largest producers of beverage cans.
  • Johnson & Johnson on many transactions on an ongoing basis, including its $30bn acquisition of Swiss biotech company Actelion Pharmaceuticals; its $3.3bn acquisition of Vogue International LLC; and the $4bn sale of Ortho Clinical Diagnostics, a leading diagnostic technology and manufacturing company.
  • Novartis AG on the $5.4bn sale of its animal health business to Eli Lilly, a matter closely scrutinized before clearance by the FTC.
  • LANXESS on its agreement with International Flavors & Fragrances (IFF) to purchase IFF’s Microbial Control business unit for $1.3bn.
  • Beiersdorf AG on its acquisition of Bayer AG’s Coppertone sun care business for $550m.
  • United Airlines on a number of joint ventures and other business opportunities.
  • ExxonMobil and Holcim Group on numerous business opportunities as well as providing ongoing counsel.



  • JD, The University of Chicago Law School.
  • BA, College of William & Mary.


  • Admitted to practice in the District of Columbia and the Commonwealth of Virginia.
  • Actively participates in the American Bar Association’s leadership.
    • Frequent speaker at ABA programs.
    • Currently chair of the ABA Antitrust Section’s Corporate Counseling Committee.
    • Formerly a vice chair of the ABA Antitrust Section’s Mergers & Acquisitions Committee.