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 is a veteran of four federal trials and one arbitration hearing. He has taken the testimony of executives and economic experts and has deposed numerous fact and expert witnesses. Sergei has obtained favorable verdicts for his clients in both bench and jury trials as plaintiff and defendant. In 2019, the National Law Journal named Sergei as a “DC Rising Star,” an award recognizing “the Washington, DC, region’s 40 most promising lawyers age 40 and under.”


Honors & Awards

  • Selected as one of The National Law Journal’s 2019 “DC Rising Stars”


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 Law Section Leadership
  • ABA Antitrust Law Section Our Curious Amalgam Podcast

Author / Co-Author

Contributing Author

  • Antitrust Law Developments Update, ABA (2019)
  • Consumer Protection Law Developments, ABA (2016)


  • Our Curious Amalgam, “What’s the Hubbub About No-Poach? Recent Antitrust Enforcement in Labor Markets,” Co-Host, ABA (2020)
  • Our Curious Amalgam, “Who Is Ready for 2021? Year in Review: Part 1,” Host, ABA (2020)
  • Our Curious Amalgam, “Who Does Antitrust Work For? An Exploration of Labor Antitrust” Co-Host, ABA (2020)
  • Our Curious Amalgam, “All Bundled Up? Making Antitrust Sense of Product Bundles and Clusters,” Co-Host, ABA (2020)
  • Our Curious Amalgam, “What is the Relationship Between Privacy and Competition? A Conversation with Commissioner Noah Phillips” Co-Host, ABA (2020)
  • Our Curious Amalgam, “Breaking News Special:  Draft Vertical Merger Guidelines,” Co-Host, ABA (2020)
  • Our Curious Amalgam, “Why Does it Matter? The Role of Big Data in Antitrust” (interview with Daniel Sokol), Co-Host, ABA (2020)
  • Our Curious Amalgam, “Why the Techlash? Antitrust Policy and Big Tech” (interview with Hal Varian), Co-Host, ABA (2019)
  • Our Curious Amalgam, “What’s The State of Things:  3 Things I Keep, 3 Things I Change” (interview with Josh Wright), Co-Host, ABA (2019)
  • Our Curious Amalgam, “What is the Secret Sauce Behind Developing a Complaint” (interview with Melinda Coolidge) Co-Host, ABA (2019)
  • Our Curious Amalgam, “Can We Have Mergers Without Tears:  Understanding the Basics of Merger Review” (interview with Mike Keeley), Co-Host, ABA (2019)


  • ABA Fundamentals of Antitrust Economics Series: Statistical Significance (November 2018)
  • ABA Consumer Protection Update (October 2015)
  • Defense of AT&T and Time Warner against DOJ’s challenge of their historic merger. The trial was characterized as a “sweeping victory for AT&T” by The Wall Street Journal. United States v. AT&T Inc., 310 F. Supp. 3d 161, 164 (D.D.C. 2018), aff’d sub nom. United States v. AT&T, Inc., 916 F.3d 1029 (D.C. Cir. 2019).
  • Defense of medical device company C.R. Bard in a tying case against competitor AngioDynamics. AngioDynamics sought over $135M (originally over $260M) in damages and an injunction forcing Bard to unbundle the technology it developed to help place catheters inside the patient.  Following a three-week trial, the jury returned a complete defense verdict, finding that Bard was not liable for tying. 
  • Representation of C.R. Bard in a tying class action brought by a hospital customer.
  • Preparation of key fact witnesses and second-chairing 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. US Airways, Inc. v. Sabre Holdings Corp., No. 11 CIV. 2725, 2017 WL 1064709 (S.D.N.Y. Mar. 21, 2017), remanded , 938 F.3d 43 (2d Cir. 2019).  Sergei also helped prepare the economic case for the 2022 retrial that resulted in the first ever jury verdict finding that the defendant monopolized a two-sided market.
  • Defense of a major tech platform in a series of two-sided market monopolization and tying cases brought by various private and government plaintiffs.

Alerts and Publications

DOJ Withdraws Longstanding Policy Statements on Information Sharing and Eliminates Safe Harbors

February 7, 2023

Making History: Six Strategic Trials in a Blockbuster Year of Antitrust Litigation

December 13, 2022

Eleventh Circuit Holds That a Franchisor and Its Franchisees May Violate Sherman Act by Entering Into No-Hire Agreements

September 12, 2022

DOJ Breathes New Life into Section 2 Criminal Enforcement

March 8, 2022

FTC Announces New 2022 HSR Reporting Thresholds and Renews Call to Congress for Additional Funding

January 25, 2022

Prompted by Sweeping Executive Order on Competition, New Leadership at US Antitrust Agencies to Launch Review of Merger Guidelines; Similar Initiatives in Europe and China May Signal Greater Convergence in Enforcement Across Jurisdictions

July 26, 2021

Unanimous Supreme Court Affirms Injunction Barring NCAA Rules that Limit Education-Related Compensation to Student Athletes

June 30, 2021

Supreme Court Holds That FTC Cannot Sue for Monetary Relief: AMG Capital Management v. FTC

April 26, 2021

In the News

Press Releases