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Casey Determan


Casey Determan is an associate in the Litigation practice. His practice focuses on advising clients on U.S. economic sanctions, antitrust, and securities laws and regulations.

Casey has experience working on securities class actions, government and internal investigations, and complex commercial litigation matters. Prior to joining the firm, Casey advised federal government clients on policy and strategy. He has helped private sector clients understand the evolving security landscape and navigate federal markets. Casey also served as a legislative aide focused on homeland security issues.



Representative matters

Advised Middle East-based company on sanctions-related due diligence in relation to a transaction involving a Russian entity.

Advised Asia-based fund on U.S. sanctions and trade restrictions related to Russia's energy sector.

Advised Asia-based multinational company on U.S. sanctions and export control compliance.

Represented Canadian financial institution in SEC and CFTC investigation.



Attorney-at-Law, New York
A&O Shearman was formed on May 1, 2024 by the combination of Shearman & Sterling LLP and Allen & Overy LLP and their respective affiliates (the legacy firms). Any matters referred to above may include matters undertaken by one or more of the legacy firms rather than A&O Shearman.