Vicki Hollub, the chief executive officer of Occidental Petroleum, is set to retire next month after a decade at the helm of the oil and gas company. She will be succeeded by Richard Jackson, the company’s current chief operating officer and incoming president. Hollub, 66, has spent over 40 years with Occidental and became the first woman to lead a major U.S. oil company when she assumed the CEO role in 2016.

During her leadership, Hollub oversaw a significant transformation of Occidental, most notably through the $38 billion acquisition of Anadarko Petroleum in 2019. The deal, which positioned Occidental as the dominant operator in the Permian Basin—the largest oil field in the United States—initially drew criticism from some shareholders due to the debt it incurred. Activist investor Carl Icahn was among the vocal opponents. However, the acquisition ultimately strengthened the company’s asset base and operational footprint.

Hollub’s tenure was marked by a strategic focus on expanding Occidental’s presence in the Permian Basin, a bet that faced challenges when crude prices fell sharply during the COVID-19 pandemic. In response, Hollub implemented spending cuts and suspended the company’s dividend to preserve financial stability. These measures helped Occidental avoid bankruptcy and positioned it for recovery as oil prices rebounded, leading to the company becoming one of the top performers in the S&P 500 in recent years.

She also spearheaded innovation initiatives, including investments in direct-air capture technology to remove carbon dioxide from the atmosphere. The company aims to bring its first such facility online this year, reflecting Hollub’s commitment to advancing low-carbon solutions amid industry transitions.

Richard Jackson, who joined Occidental in 2003 and has held various leadership roles across the company’s global operations, expressed enthusiasm about taking on his new responsibilities. He will join the company’s board, where Hollub will remain as a member. “I am grateful to be appointed president and CEO of Occidental and excited about the opportunity to execute from the strong position and capabilities that we built under Vicki’s leadership,” Jackson said.

Hollub’s rise through Occidental began in the early 1980s, and she managed overseas operations in Russia and Venezuela before rising through the ranks. Despite nearly being laid off in 2003, an internal reassignment helped solidify her trajectory within the firm. As CEO, she departed from previous conservative growth strategies, pursuing bold acquisitions and investments that reshaped the company’s profile.

Her retirement comes at a time of considerable uncertainty for the oil industry. Executives across the sector are grappling with market volatility and shifting energy demand amid geopolitical tensions and ongoing debates over the future of fossil fuels. Hollub has acknowledged the enduring importance of oil, stating in a recent interview that despite disruptions, “when the dust settles, it’s going to be clear and more bothersome to the world that oil is still incredibly important.”