Stephen I. Chazen is chief executive officer of Occidental Petroleum Corporation, an international oil and gas exploration and production company based in Houston, with operations in the United States, Middle East, and Latin America. In this role, which he has held since May 2011, Chazen is responsible for all financial management, strategy development and implementation, and operations across the company. With approximately 35,000 employees and contractors worldwide, Occidental is one of the largest American oil and gas companies, based on equity market capitalization.

Chazen’s long tenure at Occidental began in 1994, when he was appointed executive vice president of corporate development. He was named chief financial officer in 1999, serving as CFO until 2010. He was named Occidental’s president in 2007. In 2010, he became chief operating officer and was elected to the Board of Directors.

From 1982 to 1994, Chazen held various positions in the investment banking division of Merrill Lynch, ultimately rising to managing director and head of corporate finance. He cut his teeth in energy as director of project evaluation and reservoir engineering at Columbia Gas Development Corporation from 1977 to 1982, having begun his career at Northrop Corporation in the early 1970s as laboratory manager at NASA’s Lyndon B. Johnson Space Center.

As chair of the Catalina Island Conservancy’s Board of Directors, Chazen helps guide the organization toward its mission of protecting more than 62 miles of unspoiled beaches and coves, as well as more than 60 plant and animal species, along one of the oldest private land trusts in Southern California. He also is vice chair of the Aquarium of the Pacific and serves on the board of Ecolab Inc. He is a member of the board of the American Petroleum Institute, having recently served as its chair, and a member of the National Petroleum Council.

Chazen holds a bachelor’s degree in geology from Rutgers, a master’s degree in finance from the University of Houston, and a doctorate in geology from Michigan State University.