Margaret T.
Segall

Ms. Segall has represented clients on antitrust issues in connection with numerous proposed or completed deals. These representations include:

• PepsiCo’s $1.95 billion acquisition of poppi;
• Viatris’s divestitures totaling $6.94 billion in value, including the $3.335 billion combination of its biosimilars portfolio with Biocon Biologics and the divestitures of its Over‑the‑Counter, Women’s Healthcare and Active Pharmaceutical Ingredients businesses;
• Aon plc’s $13 billion acquisition of NFP;
• Cisco’s $28 billion acquisition of Splunk;
• Biogen’s $7.3 billion acquisition of Reata Pharmaceuticals;
• Deutsche Börse AG’s €3.9 billion recommended takeover offer for SimCorp A/S;

• Altra Industrial’s $5 billion acquisition by Regal Rexnord;

• RWE AG’s $6.8 billion acquisition of Con Edison Clean Energy Businesses;

• ADT’s $1.2 billion equity investment from State Farm;

• Micro Focus’s $6 billion acquisition by OpenText;

• Global Blood Therapeutics’s $5.4 billion acquisition by Pfizer;

• Afterpay Limited’s $29 billion acquisition by Block;
• GW Pharmaceuticals plc’s $7.2 billion acquisition by Jazz Pharmaceuticals plc;
• National Grid’s £7.8 billion acquisition of Western Power Distribution from PPL and the $3.8 billion sale of Narragansett Electric to PPL;
• AerCap Holdings N.V.’s $30 billion acquisition of GE Capital Aviation Services and $5.4 billion acquisition of International Lease Finance Corporation;
• DiaSorin S.p.A.’s $1.8 billion acquisition of Luminex Corporation;
• Centrica plc’s $3.625 billion divestiture of its North American energy supply, services and trading business (Direct Energy) to NRG Energy;
• Mylan N.V.’s $50 billion combination with Upjohn, a division of Pfizer, to form Viatris; its $9.9 billion acquisition of Meda; and its $5.6 billion acquisition of Abbott Laboratories’s non‑U.S. developed markets specialty and branded generics business;
• Occidental Petroleum Corp.’s $57 billion acquisition of Anadarko Petroleum Corp.;
• US Foods Holding Corp.’s $1.8 billion acquisition of five operating companies of Services Group of America;
• Pinnacle Foods Inc.’s $10.9 billion acquisition by Conagra Brands, Inc.;
• Time Warner Inc.’s $109 billion sale to AT&T;
• DreamWorks Animation SKG, Inc.’s $4.1 billion sale to NBCUniversal, LLC, a division of Comcast Corporation;
• Anheuser-Busch InBev’s $123 billion acquisition of SABMiller and the $12 billion sale of SABMiller’s U.S. and global Miller-branded businesses to Molson Coors;
• Alere’s $8 billion acquisition by Abbott Laboratories;
• H.J. Heinz Company’s $60 billion merger with Kraft Foods Group to create The Kraft Heinz Company;
• Unilever’s acquisitions of Murad and Dermalogica and its $2.15 billion sale of its North America pasta sauces business under the Ragú and Bertolli brands to Mizkan Group;
• Integrys Energy Group’s $9.1 billion acquisition by Wisconsin Energy Corporation;
• InterMune’s $8.9 billion acquisition by Roche;
• Grupo Modelo’s $20.1 billion acquisition by Anheuser-Busch InBev;
• Zale Corporation’s $1.4 billion acquisition by Signet Jewelers; and
• Life Technologies’s $15.8 billion sale to Thermo Fisher Scientific.

In addition, Ms. Segall regularly handles civil conduct investigations and complex antitrust litigation. Some of her recent and notable litigations include:

• Representing Corteva in antitrust litigation brought by the Federal Trade Commission (FTC) and 12 state attorneys general challenging certain of its rebate pricing programs as anticompetitive, as well as more than two dozen related putative class actions, centralized in North Carolina federal court, filed in the wake of the FTC’s complaint.
• Representing Epic Systems, a large provider of health information technology, in an action filed by Particle Health asserting monopolization, among other claims, arising out of alleged conduct in an alleged market for “payer platforms.”
• Represented Amgen in successfully defending against an FTC challenge to its $27.8 billion acquisition of Horizon Therapeutics, the largest in Amgen’s history. Ms. Segall was part of the team that secured a consent order that ended all litigation and cleared the path for the deal to close. In connection with this victory, the Cravath team was recognized as The Am Law Litigation Daily’s “Litigators of the Week.”
• Represented Time Warner Inc. in winning the lawsuit filed by the Department of Justice (DOJ) seeking to block Time Warner’s $109 billion sale to AT&T, which culminated in a six‑week trial.

Ms. Segall was named “Dealmaker of the Year” by Global Competition Review (GCR) in 2025, and has been repeatedly recognized by Chambers USA and The Legal 500 US, including as a “Leading Lawyer” for antitrust merger control. She has been selected for Crain’s New York Business’s list of “Notable Women in Law,” and Lawdragon’s lists of “500 Leading Global Antitrust & Competition Lawyers” and “500 Leading Litigators in America.” In addition to her inclusion in Bloomberg Law’s and GCR’s “40 Under 40” lists, Benchmark Litigation included Ms. Segall on its “40 & Under List” and consistently recognized her as a “Future Star.”

Among other accolades, Who’s Who Legal has previously recommended Ms. Segall for her antitrust work, including naming her the “Most Highly Regarded Future Leader” in Competition in North America. Ms. Segall was also recognized for her antitrust work by LMG Life Sciences, and she has received Euromoney Legal Media Group’s Rising Star Award for “Best in Antitrust/Competition.” She was additionally recognized as one of Law360’s “Rising Stars” in Competition.

Ms. Segall is a Fellow of the American Bar Foundation and a member of the Antitrust Sections for the American Bar Association, New York State Bar Association and International Bar Association, where she also serves as a Publications Officer.

Ms. Segall was born in Ann Arbor, Michigan. She received an A.B. magna cum laude from Harvard College in 2003, where she concentrated in History. She received a J.D. cum laude from Harvard Law School in 2008, where she was a member of the Board of Student Advisors and the International Law Journal and the president of Harvard Law School’s wine appreciation society.

Ms. Segall joined Cravath in 2008 and was elected a partner in 2016. She currently serves as Litigation Hiring Partner and is a member of the Diversity Committee.