New York CNN Business  — 

The Oracle of Omaha is making an even bigger bet on a major oil company as crude prices continue to surge.

Berkshire Hathaway, the conglomerate and investing firm run by billionaire Warren Buffett, increased its ownership stake in Occidental Petroleum to nearly 15% this week.

Berkshire Hathaway (BRKB) disclosed in a regulatory filing earlier this month that it had about a 9% stake in Occidental Petroleum.

That’s on top of a previous deal that gives Berkshire the right to buy nearly 84 million more Occidental Petroleum (OXY) shares. Berkshire first invested $10 billion in Occidental in 2019 to help the company buy rival Anadarko Petroleum.

Shares of Occidental Petroleum shot up about 7% Thursday, making them the best performer in the S&P 500. Occidental Petroleum’s stock has now nearly doubled in 2022.

Berkshire’s stock rose about 2% as well Thursday. Its shares have risen nearly 15% this year and are trading at a record high.

Berkshire, along with top energy stocks, has benefited from skyrocketing oil prices in the wake of Russia’s invasion of Ukraine. Crude prices are now up more than 35% this year and are above $100 a barrel.

The Occidental investment adds to Berkshire’s already significant position in the energy industry. Berkshire has a massive energy subsidiary that owns leading electric utilities such as PacifiCorp and MidAmerican, oil and natural gas pipelines and several renewable power companies.

Greg Abel, the Berkshire vice chairman who oversees Berkshire Energy and the company’s other non-financial businesses, was tapped last year to eventually succeed Buffett as Berkshire CEO.

Berkshire also has a stake in oil giant Chevron (CVX), which lost a bidding war to Occidental for Anadarko in 2019.