Sergei Zaslavsky


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Sergei Zaslavsky is an antitrust attorney with broad experience in trials, regulatory merger reviews, conduct investigations, antitrust audits, and antitrust counseling. Sergei effectively represents his clients by being both detail-oriented and strategic, and by studying his clients' businesses to understand how legal questions intersect with marketplace realities. In doing this, he is able to synthesize antitrust doctrine, economics, and facts into advocacy that is both rigorous and intuitive.

Sergei participated in two federal antitrust trials in 2015 and 2016. One was a bench trial involving a merger challenge; the other an illegal restraint of trade private action tried in front of a jury. Sergei helped prepare both fact and expert witnesses, and, in both trials, Sergei was responsible for second-chairing the direct and cross examinations of the economic experts.



Bar Admissions

  • District of Columbia
  • Maryland


  • Harvard University, J.D.: magna cum laude
  • Dartmouth College, A.B., Economics: summa cum laude

Professional Activities


  • ABA Antitrust Section


Contributing Author

  • Consumer Protection Law Developments, ABA (2016)


  • “Price Discrimination Markets in Merger Cases: Practical Guidance from FTC v. Sysco,” Antitrust (Fall 2016)


  • ABA Consumer Protection Update (October 2015)
  • Prepared key fact witnesses and second-chaired economic experts' direct and cross examinations in US Airways v. Sabre, an eight-week trial that resulted in a favorable jury verdict and garnered Global Competition Review’s “Litigators of the Week” Award for the O’Melveny trial team.
  • Represented US Airways in litigation against the DOJ in its merger with American Airlines. The representation garnered Global Competition Review’s 2014 Matter of the Year Award.
  • Represented Honeywell in its lawsuit to block competitors’ merger.
  • Represented Honeywell in its acquisition of Intermec.
  • Second-chaired economic experts’ direct and cross examinations at D.D.C. merger trial.