In Your Corner


Peter O’Mara

Peter O’Mara is a partner at O’Mara Gleason O’Callaghan and focuses his practice on business counseling and litigation in the financial services industry. A former Assistant State’s Attorney for Cook County, Peter worked for more than a decade on contract matters for many clients at the Board of Trade, drafting […]

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Peter O’Mara

Sean O’Callaghan

Sean O’Callaghan is a partner at O’Mara Gleason O’Callaghan, where his practice focuses on general business counseling and litigation. Sean has guided multimillion dollar companies through mergers and acquisitions as well as advised small startups regarding formation and partnership matters. When necessary, Sean has successfully represented his clients in state […]

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Sean O’Callaghan

Trevor Orsinger

Trevor Orsinger is of counsel at O’Mara Gleason O’Callaghan and focuses his practice on financial services, government relations, and litigation. Prior to joining O’Mara Gleason O’Callaghan, Trevor worked for the CME Group, Inc.—the world’s leading and most diverse derivatives marketplace—in their Market Regulation Department. In that role, he examined the […]

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Trevor Orsinger