OMAHA, Neb. (AP) — Warren Buffett's company has received clearance to boost its 20% stake in Occidental Petroleum to as much as 50%, but it's not immediately clear how many more shares Berkshire Hathaway plans to buy or whether it will consider buying the entire company.

Shares of the of the oil producer soared nearly 12% Friday after the Federal Energy Regulatory Commission revealed that it had approved Berkshire's request to buy up to 50% of the Houston company.

Shares slid 3% to around $69 amid a broader sell-off Monday and as speculation cooled over the potential for Berkshire to buy the entire company.

Berkshire doesn't typically comment on its stock investments beyond what it is required to disclose, and Buffett didn't respond to questions about Occidental on Monday. But Buffett told shareholders at the company's annual meeting in April that he started buying Occidental shares in late February because what the CEO was telling investors then "made nothing but sense" to him.

Berkshire's Occidental purchases and a $20 billion investment in Chevron shares early this year allowed Buffett to capitalize on the surge in oil prices after Russia invaded Ukraine.

Edward Jones analyst Jim Shanahan said he thinks it's likely that Berkshire will keep buying Occidental shares when the price drops below $60 again. The shares are up 13% in just the past 30 days, and up 130% this year. But he doesn't think it's likely that Berkshire will try to acquire the whole company unless Occidental shares fall significantly.

CFRA Research analyst Cathy Seifert said she also expects Berkshire to keep buying, but she noted that Berkshire has committed to use $11.6 billion of its roughly $105 billion in cash later this year to purchase the Alleghany insurance conglomerate.

In addition to Berkshire's massive stake in Occidental's common shares, it also holds $10 billion worth of preferred stock and warrants to buy another 83.9 million Occidental shares at $59.62 apiece. It picked up both of those in 2019 when it helped finance Occidental's purchase of Anadarko.

Besides investments, the Omaha, Nebraska-based Berkshire owns more than 90 companies outright including Geico insurance, several major utilities, BNSF railroad and an assortment of manufacturing and retail companies including See's Candy, Dairy Queen and Precision Castparts.