George E. Mastoris, Partner

George Mastoris is a litigation partner in Winston & Strawn’s New York office. Mr. Mastoris practices complex commercial litigation and has experience in antitrust, bankruptcy litigation, intellectual property litigation, and international arbitration. In the antitrust and commercial contexts, Mr. Mastoris has represented a broad array of clients in civil and criminal litigations at both the trial and appellate level, including major manufacturers, telecommunications companies, banks, commercial lenders, hedge funds, pharmaceuticals, and biotech firms. Mr. Mastoris also has extensive experience in bankruptcy, representing both debtor and creditor entities in a wide variety of proceedings, as well as in international arbitration practice.

Representative Matters:

• Sheridan Healthcorp, Inc.—In late 2010, Mr. Mastoris and a team of attorneys successfully obtained a complete and indefinite stay of a federal antitrust action brought against Sheridan by AvMed, Inc., a Florida insurer which previously had been sued for breach of contract by Sheridan in state court. The state court suit, which also involved antitrust counterclaims against Sheridan, was recently resolved on terms Sheridan considered very favorable.
• Great West Investors LP—In an action for breach of contract and reformation with more than $350 million at stake, Mr. Mastoris is currently representing Great West, the investment arm of mulitnational conglomerate Power Corp., against Thomas H. Lee Partners, one of the world’s largest private equity funds. 
• Capmark Financial Group—Mr. Mastoris played a leading role on a bankruptcy trial team which successfully fought off a derivative standing challenge brought against the debtor by unsecured creditors seeking to bring preference and fraudulent conveyance claims.
• Omnicare, Inc—Mr. Mastoris has represented Omnicare, Inc., the nation’s largest institutional pharmacy, in connection with a variety of matters. Most recently, he served as the attorney responsible for the day-to-day management of a $1.1 billion suit brought by Omnicare against UnitedHealth Group for violation of federal and state antitrust laws in connection with the provision of medications under Medicare Part D, as well as the subsequent and ongoing appellate proceedings.
• MedImmune, Inc.—Mr. Mastoris and other lawyers at DL were instrumental in helping MedImmune obtain a Supreme Court ruling overturning Federal Circuit precedent that licensees in good standing were barred from seeking declarations of non-infringement, invalidity, or unenforceability.
• In arbitration before the LCIA, Mr. Mastoris represented a major European telecommunications concern which had been sued by an American aerospace company for breach of contract, successfully settling the arbitration for a fraction of the amount sought by the arbitration demand.

Education

Speeches and Publications

• Co-Author with Robert de By, “How to Avoid a Culture Clash in Business Mediations,” The Reporter (March 2007).