Brian focuses on a variety of antitrust matters, including litigation, merger review, and counseling.

Prior to joining the firm, Bran practiced antitrust law at another international law firm. Brian earned his LL.M. in competition law at New York University where he received the Frank T. Diersen Prize for graduating number one in his program.


Representative matters

Health insurers in multidistrict litigation and several opt-out litigations alleging antitrust violations under Sections 1 and 2 of the Sherman Act.

Contact lens retailer in parallel government and class action litigations challenging a series of trademark settlements as antitrust violations.

Airline in trials against the Department of Justice related to a joint venture and an attempted merger.

Video game console manufacturer in a class action litigation challenging its decision to stop selling certain products through retailers as a Section 2 violation.

Published Work

  • Hauser, Brian, Co-author, (2016) “Reinvigorated Antitrust Enforcement: Lessons for Non-Party Witnesses from Recent Merger Litigation,” The Antitrust Source
  • Hauser, Brian, Co-author, (2015) “How a Recent Supreme Court Ruling on Antitrust Laws Could Impact Providers: A Law Review Q&A,” The Daily Briefing, The Advisory Board Company 



Attorney-at-Law, Washington D.C.

Attorney-at-Law, Illinois


LL.M., Competition, Innovation, and Information Law, New York University School of Law

Frank T. Diersen Prize for Top Performance in LL.M. program

J.D., DePaul University College of Law

Staff, DePaul Law Review

Order of the Coif

B.B.A., Accounting, Loyola University Chicago

A&O Shearman was formed on May 1, 2024 by the combination of Shearman & Sterling LLP and Allen & Overy LLP and their respective affiliates (the legacy firms). Any matters referred to above may include matters undertaken by one or more of the legacy firms rather than A&O Shearman.