Keller Postman LLC Announces Addition of Partner Jason Zweig to Chicago Office

Zweig Primed To Support Growth of Antitrust & Class-Action Practices

National plaintiffs’ law firm Keller Postman LLC announced today that Jason Zweig has joined the firm as Partner. Zweig is a seasoned class-action lawyer with a breadth of experience representing plaintiffs in antitrust, consumer, product-liability and securities matters. In his new role, Zweig will contribute to the growth of Keller Postman’s antitrust and class-action practices.

Zweig joins Keller Postman from Hagens Berman Sobol Shapiro LLP, where he was Managing Partner of the Chicago office. Before relocating to Chicago in 2015, Zweig opened Hagens Berman’s New York office when he joined the firm in 2011.

Zweig said he is eager to apply his legal experience and entrepreneurial drive to his new role.

“Keller Postman has an energy that one would expect in a startup enterprise. Everyone here is teeming with passion for the law and growing this firm,” Zweig said. “I’m excited to contribute to that growth and to help continue to establish Keller Postman as a major player in the antitrust class-action arena and the broader plaintiffs’ bar.”

Among other notable matters, Zweig led Hagens Berman’s representation of companies that opted out of the class in In re Payment Card Interchange Fee and Merchant Discount Litigation, including FedEx, American Airlines, Southwest Airlines, Alaska Airlines, JetBlue, British Airways, Hawaiian Airlines, DSW, and The Minnesota Twins.

Prior to joining Hagens Berman, Zweig was a Partner at Kaplan Fox & Kilsheimer LLP. At Kaplan Fox, he played significant roles in some of the largest antitrust class actions in history, including the High Fructose Corn Syrup Antitrust Litigation, Hydrogen Peroxide Antitrust Litigation, and the Plastics Additives Antitrust Litigation.

Zweig earned his law degree from Columbia Law School, where he was Executive Editor of the Columbia Journal of Environmental Law. During law school, Zweig served as a judicial intern to Judge Jed S. Rakoff on the U.S. District Court for the Southern District of New York. He earned his undergraduate degree from Indiana University.

– – –

*As of April 2022, the firm has changed its name from Keller Lenkner to Keller Postman.