Marc De Leeuw has been a partner at Sullivan & Cromwell since 2001. His litigation practice includes representing clients in a variety of areas, including intellectual property, securities, antitrust, real estate, contract, bankruptcy, and many other commercial matters.
Marc has represented clients before arbitration tribunals, the International Trade Commission, New York and New Jersey state trial and appellate courts, numerous federal district courts and Courts of Appeals and the U.S. Supreme Court. He has represented clients in trials and arbitration hearings in intellectual property, antitrust, tort, contract and insurance cases.
Marc has been recognized many times as a New York Super Lawyer and as a “Future Star” by Benchmark Litigation. He has been named multiple times in the AmLaw “Litigator of the Week,” and by the National Law Journal for his successful representation of Microsoft in a major antitrust jury trial.
Professional Activities and Community Involvement
- Co-author of “Declaratory Judgments” chapter in Commercial Litigation in New York State Courts
- Serves as Chair of the Board of Directors of Mobilization for Justice
- Represented pro bono the St. Andrew’s Society of the State of New York
- Served on the New York City Bar Association Judiciary Committee
- PLI Panel Member, “Handling a Securities Case: From Investigation to Trial and Everything in Between” (2012, 2013)
- Author of “Recent Patent Decisions and How They Affect Patent Law,” in Developing a Patent Strategy (2010)
- Speaker at professional conferences concerning cross-border class actions and investment company and patent litigation