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Ann Marie Duffy

Ann Marie Duffy

T +1 202 263 3418
F +1 202 263 3300
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Ann Marie Duffy is a partner in Mayer Brown's Intellectual Property practice. Ann Marie specializes in high-stakes litigation and trial work.  She has significant experience in complex commercial litigation, including intellectual property, breach of contract, qui tam, antitrust, and fraud.

Ann Marie's patent litigation experience has involved a range of technologies, including medical  devices, data storage, online advertising,  online computer coupon generating software, MP3 audio compression, JPEG image compression, and battery spill-containment devices.

Ann Marie has significant trial and oral argument experience.  Early in her career, she first chaired a bench trial in Virginia state court securing a victory for her client in a breach of contract matter.  Recently, Ann Marie second chaired a $600 million patent trial in the District Court of Delaware in a case where total damages exceeded $2 billion.  At this trial, Ann Marie directed and crossed several witnesses, argued numerous evidentiary issues, argued final jury instructions, and managed the war room for the entirety of the three week trial.  Ann Marie has also participated in a trademark trial in the Eastern District of Virginia and handled numerous administrative proceedings in various state and federal agencies.  Ann Marie has briefed and argued an appeal to the United States Court of Appeals for the Tenth Circuit and three appeals before the United States Court of Appeals for the District of Columbia Circuit. She has also participated in cases in a number of federal courts, including the Eastern District of Virginia, District of Delaware, Central District of California, Eastern District of Pennsylvania, District of Maryland, Southern District of New York, Northern District of Ohio, Western District of Virginia, Eastern District of Texas, and Western District of Tennessee.

Ann Marie is the co-hiring partner for the Washington D.C. office, a member of the firm’s Pro Bono Committee, and a member of the firm’s Committee on Professional Advancement (CoPA).

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