By Jonathan Stempel

Berkshire Hathaway Inc said on Thursday it had acquired more shares of Occidental Petroleum Corp, boosting its stake in the oil company to 24.4%.

In a regulatory filing, the conglomerate controlled by billionaire Warren Buffett said it paid about $201 million for 3.46 million Occidental shares between May 16 and 18.

Berkshire has bought Occidental shares on each of the last six trading days, paying about $327 million for 5.62 million shares.

It now owns about 217.3 million Occidental shares worth about $12.7 billion.

Berkshire also owns approximately $9.5 billion of Occidental preferred stock carrying an 8% annual dividend, plus warrants to buy $5 billion of Occidental common shares at $59.62 each.

Occidental's share price closed Thursday down 67 cents at $58.25.

Berkshire acquired the preferred stock and warrants in 2019 when it helped finance Houston-based Occidental's purchase of Anadarko Petroleum Corp.

It began buying common shares early last year, around when Russia invaded Ukraine and as oil prices rose.

At Berkshire's annual shareholder meeting on May 6, Buffett pointed out Occidental's presence in the Permian Basin, which accounts for a significant amount of U.S. crude production, and called Occidental CEO Vicki Hollub an "extraordinary manager."

He also tried to end speculation that Berkshire might buy Occidental and further diversify its own energy portfolio.

"We're not going to buy control," he said. "We've got the right management running it... we wouldn't know what to do with it."

Berkshire had amassed a 22.6% stake in the BNSF railroad before paying $26.5 billion for the remainder in 2010.

Buffett, 92, has run Berkshire since 1965.

The Omaha, Nebraska-based company owns dozens of businesses, including Geico car insurance and many retail and manufacturing companies, as well as stocks such as Apple Inc.

(Reporting by Jonathan Stempel in New York. Editing by Gerry Doyle)