Aton Arbisser

Retired Partner

Aton Arbisser is a retired partner who has won cases at both the trial and appellate levels, in both federal and state court. Early in his career he wrote the briefs that convinced the California Supreme Court that the state's antitrust laws did not apply to a multibillion-dollar merger. In 2012, he successfully argued the appeal on behalf of 15 pharmaceutical manufacturers accused of conspiring to fix the prices, defending the summary judgment he and partner Saul Morgenstern had won in the trial court on behalf of the industry. Mr. Arbisser also has successfully defended or resolved numerous antitrust class actions in federal court and indirect purchaser cases in state court. In addition, Mr. Arbisser counseled clients on a wide range of antitrust issues.

Mr. Arbisser's practice expanded far beyond his antitrust roots to encompass a broad range of complex litigations, including consumer fraud class actions and mass torts. He has been nationally recognized for his successes in defending pharmaceutical companies in product liability cases and related consumer class actions. In the phenylpropanolamine (PPA) products liability litigation, he chaired the joint defense team on experts and science issues, defeated a class action seeking refunds on millions of dollars of product containing PPA that had been withdrawn from the market, won the first-in-the-nation PPA trial and then successfully argued the appeal.

A frequent lecturer and author in the areas of antitrust and class action law, Mr. Arbisser was recently appointed to the Executive Committee of the Antitrust and Unfair Competition Section of the California State Bar.


  • JD/MA, Joint Degree Law & Economics, University of California, Berkeley School of Law, 1982
  • AB, Princeton University, 1978, magna cum laude
  • California
  • New York
  • US Court of Appeals for the Ninth Circuit
  • US District Courts for the Central, Eastern, Northern, and Southern Districts of California
  • US District Court, Eastern District of New York
  • US District Court, Southern District of New York
  • Member, State Bar of California
  • Member, Executive Committee Antitrust and State Unfair Competition Section, State Bar of California
  • Member, American Bar Association
  • Vice-Chairman, Robinson-Patman Act Committee, Antitrust Section, American Bar Association
  • Editorial Board, Antitrust Law Development, Antitrust Section, American Bar Association

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