Omar is the author of the two leading competition law texts, The Annotated Competition Act and The Annotated Investment Canada Act, both published annually by Thomson Carswell. He is a non-practising member of the Law Society of England and Wales.

Omar is a member of the Executive Committee of Canadian Bar Association's National Competition Law Section and is past-chair of the Section's Mergers and Foreign Investment Review committees. He is also a member of the Foreign Investment Review Committee and the Mergers Committee of the Competition Law Section for the Canadian Bar Association. In addition, he is a member of the Antitrust Law Section and International Law Section for the American Bar Association, as well as for the International Bar Association.

Omar is also a member of the CD Howe Institute's Competition Policy Council and the Practical Law Canada Advisory Board. He is also a private-sector adviser to the International Competition Network, a multijurisdictional organisation that seeks to facilitate effective international cooperation in competition law enforcement.