Editor's note: This article has been updated with analyst commentary. 

Warren Buffett’s Berkshire Hataway continues to buy up Occidental Petroleum stock, reporting the purchase this week of roughly 10.48 million shares for $588.6 million.

Buffett’s stock purchases, from Dec. 11 through Dec. 13, were made at an average share price of $56.42, according to Securities and Exchange Commission filings. The purchases coincided with Occidental’s Dec. 11 announcement to buy CrownRock LP for $12 billion.

Truist analyst Bertrand Donnes said the move can be interpreted as Buffet endorsing Occidental increasing its exposure to oil and gas with the  CrownRock acquistion or as a signal of continued general support of the stock. "It’s interesting that he was supporting a move back to traditional oil and gas. … He has a large existing position, [so] it’s logical for him to increase his position and support the shares at a time where most investors would be watching the performance to partially judge whether the deal was good or not,” Donnes said.

The purchases bring Berkshire's stake in Occidental to about 27%, Reuters reported. The company also holds preferred shares and warrants to acquire another 83.8 million Occidental shares for $4.7 billion, or $56.62 each.

The shares and warrants were obtained as part of a deal that helped Occidental finance its 2019 purchase of Anadarko Petroleum. If exercised, the warrants would bring Berkshire's total ownership of Occidental to 33%, Reuters reported.

Since August 2022, Buffett has had federal authorization to buy up to 50% of Occidental.

In October, Occidental CEO Vicki Hollub addressed Buffett’s investments in the company, saying that they are based on his bullish view of oil prices and because “he knows that our focus has been … to narrow down to the best possible assets.”

“Warren Buffett just looks at performance,” Hollub said at the Energy Intelligence Forum 2023 in London.