Occidental Petroleum Corporation, an international oil and gas exploration and production company, has appointed Marcia Backus as vice president and general counsel, effective Oct. 1.

Backus currently is a partner at law firm Vinson & Elkins, where she heads the firm's Energy Transactions/Projects Practice Group, representing industry and private equity companies in domestic and international mergers and acquisitions, joint ventures, private equity investments, project development and other energy transactions. She has served in numerous leadership positions with Vinson & Elkins, including on the firm-wide management committee, co-chair of the corporate department and as chair of the partnership admissions committee.