Occidental Petroleum

Occidental Petroleum was founded in Los Angeles in 1920 and long remained a small, largely unprofitable driller.⁠[1]

In 1956 Armand Hammer and his wife each invested $50,000 in two oil wells; by July 1957 he was company president.⁠[2]

In 1966 the company found a billion-barrel oil field in Libya.⁠[2]

It ceased operations in Libya in 1986 and resumed them in 2005.⁠[1]

In 1968 Occidental purchased Hooker Chemical, unaware of its problems.⁠[2]

In 1982 the company bought Cities Service Co. for $4 billion, then one of the biggest corporate takeovers ever.⁠[3]

In 1981 it acquired meatpacker Iowa Beef Packers (IBP), selling 49.5 percent of it to the public in 1987.⁠[2]

In 1987 its chemical operations became Dallas-based Occidental Chemical Corporation.⁠[1]

In July 1988 the Piper Alpha platform, operated in the U.K. North Sea by Occidental Petroleum (Caledonia) Ltd., exploded and burned, killing 167 people. Lord Cullen’s inquiry found the company “too easily satisfied that the permit to work system was operating correctly” and recommended moving offshore safety regulation to the Health and Safety Executive.⁠[4]

Hammer, chairman and CEO since 1957, died in Los Angeles on December 10, 1990, at 92. President Ray R. Irani was elected chairman and CEO. Occidental was then the seventh-largest U.S. oil company, with more than 53,000 employees.⁠[3]

On December 21, 1995, Occidental Chemical Corporation agreed to pay $129 million to repay federal Love Canal cleanup costs and interest. Its predecessor Hooker Chemical had dumped about 20,000 tons of chemicals into an abandoned canal in Niagara Falls, New York, from 1942; the disaster led Congress to enact the Superfund law in 1980.⁠[5]

It bought California’s Elk Hills gas deposits in 1998 and Permian Basin holder Altura Energy in 2000. Stephen I. Chazen succeeded Irani as CEO in 2011.⁠[1]

On February 14, 2014, Occidental announced it would spin off its California assets as an independent public company and move its headquarters from Los Angeles to Houston, keeping exploration and production in Texas, the Middle East and Colombia, midstream and marketing, and OxyChem. Chazen said, “Creating two separate energy companies will result in more focused businesses.”⁠[6]

In December 2015 the board made Vicki A. Hollub president and chief operating officer, named her a director, and announced she would succeed Chazen as CEO at the 2016 annual meeting.⁠[7]

On April 29, 2016, Hollub became CEO, the first female CEO of a major U.S. energy explorer; she had overseen Western Hemisphere fields pumping almost half the company’s output.⁠[8]

On April 24, 2019, countering a ChevronChevronChevron is an integrated energy company headquartered in Houston, Texas, United States, whose shares trade on the New York Stock Exchange (ticker CVX). Its history dates back to Pacific Coast Oil Co., founded in 1879, and it adopted the name Chevron Corporation after acquiring Gulf Oil in 1984.Open the full entry bid, Occidental offered $76 per Anadarko share. On April 30 Berkshire Hathaway committed $10 billion for 100,000 shares of 8 percent cumulative perpetual preferred stock and a warrant for up to 80 million common shares at $62.50, contingent on the deal closing.⁠[9]

On May 9, 2019, Chevron said it would not raise its offer, leaving Anadarko to pay it a $1 billion termination fee. Chevron CEO Mike Wirth said, “Winning in any environment doesn’t mean winning at any cost.”⁠[10]

On August 8, 2019, Occidental completed its acquisition of Anadarko Petroleum Corporation, valued at about $55 billion including assumed debt; each Anadarko share received $59.00 in cash plus 0.2934 Occidental shares. The company expected at least $3.5 billion in annual synergies.⁠[11]

By November 2019 it had completed the $3.9 billion sale of the Mozambique assets and planned to sell the remaining Africa assets to Total.⁠[12]

Occidental announced the $12 billion cash-and-stock purchase of Midland Basin operator CrownRock in December 2023 and completed it in August 2024, funded partly with $9.1 billion of new debt and about $1.7 billion of common equity. CrownRock, a CrownQuest Operating and Lime Rock Partners joint venture, held over 94,000 net acres.⁠[13]

The deal had drawn a second request from the U.S. Federal Trade Commission. At closing the company said Ecopetrol would not buy a stake in CrownRock.⁠[14]

On October 2, 2025, Occidental agreed to sell OxyChem to Berkshire Hathaway for $9.7 billion in cash, planning to use $6.5 billion to cut debt. Berkshire then owned more than 25 percent of Occidental. Occidental kept OxyChem’s legacy environmental liabilities, managed by Glenn Springs Holdings.⁠[15]

OxyChem makes basic chemicals including chlorine, caustic soda, vinyl chloride monomer and polyvinyl chloride.⁠[16]

Occidental is a Delaware corporation. As of December 31, 2025, it had 10,412 employees in continuing operations, excluding OxyChem.⁠[17]

On January 2, 2026, Occidental completed the sale of OxyChem to Berkshire Hathaway for $9.7 billion in cash, subject to customary adjustments. Hollub said the transaction “accelerates our strategy to strengthen Occidental’s balance sheet.”⁠[18]

Berkshire Hathaway paid cash consideration of approximately $9.4 billion.⁠[19]

In 2025 Occidental had net sales of $21.593 billion (2024: $22.019 billion), net income attributable to common stockholders of $1.647 billion ($1.61 per diluted share) and production of 1,434 thousand barrels of oil equivalent per day. It had cut debt by $5.8 billion since mid-December 2025, to $15.0 billion of principal debt.⁠[20]

On May 1, 2026, Occidental announced that Hollub would retire on June 1 and remain a director, and that chief operating officer Richard Jackson would succeed her as president and CEO and join the board. Jackson joined in 2003 in the Middle East operations; Hollub had worked at Occidental for more than 40 years.⁠[21]

As of June 30, 2026, Berkshire Hathaway owned 26.7 percent of Occidental’s common stock. Its Occidental preferred stock had a liquidation value of about $8.5 billion, accrues 8 percent dividends and is redeemable at Occidental’s option from 2029; its warrants cover up to 83.9 million shares at $59.59.⁠[19]