Michael H. Gruenglas represents corporations and individuals in complex disputes involving a wide range of corporate, commercial and securities matters.


Mr. Gruenglas regularly appears before the federal and state courts, as well as in arbitration tribunals. He repeatedly has been selected for inclusion in Chambers USA: America’s Leading Lawyers for Business.

Mr. Gruenglas has represented a broad spectrum of clients, both as plaintiffs and defendants, in cases involving claims for breaches of contract, fraud, breaches of fiduciary duty, tortious interference, antitrust issues and violations of civil RICO, among others. He has represented a number of publicly traded corporations, including McKesson HBOC and Cendant Corporation, in some of the most significant securities class actions in recent years as well as in many related lawsuits. Mr. Gruenglas has conducted internal corporate investigations relating to such representations. He also has represented various public corporations in hotly contested takeovers. Mr. Gruenglas also focuses on technology-related litigation and serves on the firm's technology and electronic discovery committees.

In 2009, Mr. Gruenglas successfully represented Biogen Idec Inc. in a high-profile breach of contract dispute with Elan Corp. regarding the parties’ buyout rights in the event of a change of control. After a five-hour oral argument, U.S. District Court Judge Deborah Batts denied Elan’s motion for a preliminary injunction and found that Elan was not likely to prevail on the merits, effectively ending the action. The case was heavily covered by all major media. From 2004 to 2009, Mr. Gruenglas successfully defended Jakks Pacific, Inc. against federal RICO and antitrust claims brought by WWE, Inc., achieving the complete dismissal of the RICO, Sherman Act, and Robinson Patman Act claims, which was subsequently affirmed by the Second Circuit. Mr. Gruenglas also defended Jakks Pacific in the related securities class actions. In May 2008, after a full evidentiary trial before the American Arbitration Association, Mr. Gruenglas won a complete victory on behalf of SanDisk in an arbitration against Samsung Electronics. The dispute, which has garnered significant media attention, related to the delivery of critical electronic components and patent licenses. Mr. Gruenglas represented CTF Hotel Holdings, Inc. and Hotel Property Investments Ltd. in their arbitration and federal actions against Marriott International, Inc., which included a seven-week evidentiary hearing before an American Arbitration Association panel. Acting as plaintiffs’ counsel, Mr. Gruenglas obtained a more than $33 million summary judgment award in the New York State Supreme Court, Commercial Division, against a New York bank accused of using its reorganization as a Delaware corporation as a means of evading its obligations to its preferred shareholders. He also defended Morgan Stanley & Co. in class actions involving alleged ERISA violations and successfully litigated a complex spyware/invasion of privacy action.



  • J.D., New York University School of Law
  • B.S., City University of New York, Brooklyn College


  • New York

Michael H. Gruenglas

Partner, Complex Litigation and Trials