Marathon Petroleum, ranked No. 16 on the Fortune 500, announced that Maryann T. Mannen will succeed Michael J. Hennigan as CEO and join the board of directors, effective August 1. Mannen, currently the company’s president since January 1, will become the first female CEO in Marathon’s history. She has been serving as Executive Vice President and Chief Financial Officer since 2021, a role in which she also broke new ground as the company’s first female CFO.
Before joining Marathon Petroleum, based in Findlay, Ohio, Mannen held significant leadership roles at TechnipFMC, a global engineering services and energy technology firm. She served as Executive Vice President and CFO at TechnipFMC, as well as its predecessor, FMC Technologies, which she joined in 1986. Mannen's extensive experience in the energy sector spans 38 years, making her a seasoned veteran in the industry.
Marathon Petroleum operates the largest refining system in the United States, with a crude oil refining capacity of 3 million barrels per calendar day across 13 refineries. In 2021, Marathon completed the $21 billion sale of Speedway to 7-Eleven, a major strategic move for the company. The firm's broad operations and significant refining capacity underscore its critical role in the energy sector. The transition in leadership comes at a time when there is an increasing trend of CFOs moving into CEO positions. Data from 674 Fortune 500 and S&P 500 companies indicate that 8.4% of CEO roles were filled by CFOs last year, up from 5.8% in 2013. This shift reflects the growing recognition of the strategic and financial acumen CFOs bring to the top executive role.
Fortune recently reported that women now hold more than 10% of CEO positions within the Fortune 500, marking a significant milestone in gender diversity at the highest levels of corporate leadership. Mannen’s appointment as CEO of Marathon Petroleum is a notable addition to this progress. Hennigan, the outgoing CEO, expressed confidence in Mannen’s leadership capabilities, given her substantial contributions to Marathon and her proven track record in the energy sector. Her tenure at Marathon has been marked by strategic financial management and operational excellence, positioning the company for continued success.
As Marathon Petroleum transitions under Mannen’s leadership, the company is poised to navigate the evolving energy landscape with a focus on innovation and sustainability. Mannen’s appointment represents not only a significant personal achievement but also a milestone for Marathon Petroleum as it continues to advance its position in the global energy market.