Hollub is reportedly planning to retire after 10 years as one of the most powerful women in the male-dominated oil and gas industry, with an announcement expected later this year. Occidental COO Richard Jackson is set to move into the role, according to reports.

Warren Buffett, whose Berkshire Hathaway is Occidental’s largest shareholder, has praised Hollub as someone who “does know how to separate oil from rock and that’s an uncommon talent, valuable to her shareholders and to her country.”

Last year, Berkshire Hathaway paid $9.7 billion for Occidental’s OxyChem business in a deal that helped the oil and gas exploration and production company to pay down debt and focus on its US oil and gas portfolio.

Hollub’s milestones include the company’s Anadarko Petroleum purchase for about $55 billion in 2019 — after outbidding oil major Chevron Corp. The company also acquired CrownRock in 2024 for $12 billion.

“We have, now, decades of development opportunity in oil and gas,” Hollub told CNBC last year. “Our portfolio is the best it’s ever been.”