Gary M. Osen

Gary M. Osen, the Firm’s managing partner, has litigated complex cases, often of international dimensions, throughout his career, including a wide variety of high profile cases addressing unusual and challenging legal issues. He served as lead trial counsel in the landmark Linde v. Arab Bank, Plc case, which resulted in the first, and still only, jury verdict against a financial institution under the Anti-Terrorism Act. Reuters described the trial as “proving that American lawyers will stop at nothing to establish…liability – surely a tribute to their doggedness and a solace to their clients.” For Mr. Osen’s work on that matter, he was named one of Public Justice’s Trial Lawyers of the Year in 2016.


Mr. Osen currently serves as lead counsel in several major counter-terrorism financing cases pending in federal courts, including: Freeman v. HSBCBartlett v. SGBL; Averbach v. Cairo-Amman Bank; and several other matters.


He served as co-lead counsel in the leading case of Wortham v. KarstadtQuelle AG, described by The Wall Street Journal as “one of the largest single family Holocaust claims ever.” Mr. Osen has also successfully represented hundreds of Nazi victims in their pursuit of legal claims against the German government and private entities.


Mr. Osen has what The Washington Times described as “a penchant for tackling larger-than-life cases” and developing new and creative legal theories that challenge some of the world’s largest companies and most powerful governments. The New York Times has recognized him as “an internationally consulted legal authority on terror financing.” Businessweek has also noted that “Osen is doing what good lawyers do: capitalize on how jurisprudence evolves to fit the times.” He has been quoted and featured in most of the leading newspapers and magazines in the United States and around the world, including  Time Magazine, The New York Times, The Wall Street Journal, The Times of London, The Economist, Der Spiegel, and Haaretz. He has also appeared on the Fox News Channel, CNN, MSNBC, the BBCBloomberg, and Germany’s ARD and ZDF.  


Mr. Osen graduated from George Washington University Law School in 1992 and earned his undergraduate degree from Rutgers University with high honors in 1989. Mr. Osen also received an M.A. in Political Science from George Washington University in 1993. He is a member of the New York and New Jersey Bars and is admitted to practice before the United States District Court for the District of New Jersey, the United States District Court for the Eastern and Southern Districts of New York, the United States District Court for the District of Columbia, the United States Court of Appeals for the Second Circuit, the United States Court of Appeals for the Third Circuit and the United States Supreme Court.


  • Rutgers University (B.A., with high honors, 1989)
  • George Washington University, The National Law Center (J.D., 1992)
  • George Washington University (M.A., Political Science, 1993)
  • Undergraduate Fellow, Eagleton Institute for Politics, New Brunswick, New Jersey



  • U.S. District Court, District of New Jersey, 1993
  • U.S. Court of Appeals for the Third Circuit, 2003
  • U.S. District Court, Eastern District of New York, 2004
  • U.S. District Court, Southern District of New York, 2005
  • U.S. Court of Appeals for the Second Circuit, 2010
  • Supreme Court of the United States, 2013

  • U.S. District Court, District of Columbia, 2016

  • U.S. Court of Appeals for the Seventh Circuit, 2017


  • New Jersey, 1993
  • Pennsylvania, 1993 (inactive)
  • New York, 2003