Shari Ross Lahlou


Shari Ross Lahlou


Washington, D.C. | 1900 K Street, NW, Washington, DC, United States of America 20006-1110
+1 202 261 7923 | +1 202 261 3333


Shari Ross Lahlou is an experienced first-chair trial lawyer who focuses her practice on antitrust and other complex litigation matters. She regularly handles high-stakes, high-profile matters for Fortune 500 companies and is well-regarded for achieving successful outcomes and delivering excellent service. Ms. Lahlou has experience in a broad array of industries, including healthcare, telecommunications, hospitality, chemicals, and transportation.

Ms. Lahlou represents clients throughout the United States and around the globe in federal and state courts and in government investigations addressing a diverse range of antitrust, contract and business tort, licensing, and intellectual property issues. She has extensive experience with class actions and multi-district litigation, and regularly argues dispositive and class motions on behalf of her clients and joint defense groups. She has obtained significant trial court and appellate victories for her clients across a range of antitrust matters, including: claims alleging conspiracy, monopolization, tying, and exclusive dealing.

Ms. Lahlou is also recognized for her extensive antitrust merger litigation experience on high-profile transactions. Recently, she represented PeroxyChem in obtaining approval of its $640 million merger with Evonik following a 2-week trial in D.C. federal court, which represented the first FTC merger-challenge loss in 5 years. She was also lead trial counsel for Humana in the 13-day trial of the Department of Justice’s lawsuit to block its $39 billion proposed merger with Aetna. Ms. Lahlou also represented AT&T in multiple mergers, including its recent headlining acquisition of Time Warner and its earlier proposed acquisition of T-Mobile.

The market acknowledges Ms. Lahlou as a leading litigation lawyer. In 2020, she was selected as one of Law360's MVPs of the Year in the Competition category. Chambers USA lists her as an “Antitrust Litigation Specialist” whom “peers rate ... as a ‘very, very strong antitrust litigator.’” In 2018, Global Competition Review named her “Litigator of the Year” and the National Law Journal awarded her 2016 “M&A-Antitrust Trailblazer.”

Prior to joining Dechert, Ms. Lahlou was a partner at another global law firm, where she served as Co-Chair of the Antitrust Group.

  • PeroxyChem (One Equity Partners) in obtaining approval of its $640 million merger with Evonik following a two-week trial in D.C. federal court. This ended the FTC's five-trial win streak in D.C. federal court, allowing the deal to close.
  • CSX Transportation in the defense of Sherman Act Section 1 multidistrict class action litigation alleging conspiracy to fix fuel surcharge prices. Prevailed in defeating class certification on remand from the D.C. Circuit’s prior opinion vacating the district court’s previous ruling certifying the class.
  • Marriott in a class action antitrust lawsuit against the major hotel companies alleging the companies engaged in a conspiracy regarding keyword advertising.
  • Humana in antitrust litigation regarding allergy testing and allergen immunotherapy.
  • AT&T as antitrust trial counsel, helping guide courtroom strategy in the landmark trial victory against the U.S. Department of Justice to gain clearance for AT&T’s US$85 billion vertical acquisition of Time Warner.
  • Chemours (and legacy entity DuPont) in defense of Sherman Act Section 1 class action and opt-out litigations alleging conspiracy to fix the price of titanium dioxide. Prevailed in federal district court on summary judgment in an opt-out case brought by Valspar; summary judgment affirmed by the Third Circuit.
  • Owens & Minor, the nation’s leading distributor of medical and surgical products, in litigation alleging tying and exclusive dealing. Prevailed in federal district court on summary judgment, which was affirmed by the Tenth Circuit.
  • Humana as lead trial counsel in connection with the U.S. Department of Justice’s challenge of the company’s proposed merger with Aetna, valued at approximately US$39 billion.
  • AT&T in its proposed acquisition of T-Mobile.
  • AT&T in litigation over exclusive service provider relationship for iPhones.
  • RICO, a leading copier OEM in a case alleging violations of Sherman Act Section 2 using an aftermarket theory, and RICO.
  • DuPont in its prosecution of trade secrets claims and its defense of a Sherman Act Section 2 counterclaim.

Includes matters handled at Dechert or prior to joining the firm.

  • Dickinson College, B.A., cum laude
  • The George Washington University Law School, J.D., Order of the Coif, with highest honors
  • District of Columbia
  • Maryland
Speaking Engagements
  • Nuts and Bolts: Sherman Act Section 2 - ABA program, Teleconference (June 5, 2020)
  • Defending Deals where Coordination is a Primary Theory of Harm: Lessons from Tronox/Cristal and Evonik/PeroxyChem - ABA program – M&A committee (May 21, 2020)
  • How to Win an Antitrust Merger Trial: Lessons from FTC v. Evonik/PeroxyChem - Dechert LLP, Webinar (May 7, 2020)
  • Lessons from The Field: The Evonik Litigation - W@Competition (May 6, 2020)