Warren Buffett (pictured), chair of Berkshire Hathaway
This equated to nearly 10.5 million shares and brings Berkshire Hathaway's stake to around 27%.
Berkshire Hathaway, which is overseen by chair Warren Buffet, bought 3.7 million worth of shares in March 2023 for around $216m.
Buffett's company began buying large quantities of Occidental stock in 2022, around he time Russia invaded Ukraine.
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Occidental Petroleum closed a deal to acquire CrownRock earlier this week.
CrownRock is one of the major US private shale oil producers and Occidental agreed to a $12bn purchase, including debt.
Occidental said it would fund the CrownRock acquisition with a combination of cash and shares, and intended to take on $9.1bn of new debt.
Berkshire Hathaway has been making strides into the energy space as an independent player, with the launch of Berkshire Hathaway Energy.
A subsidiary of Berkshire Hathaway, it owns 29% of the company and sits across several energy producers.
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