Warren Buffett's Berkshire Hathaway bought around 2.57 million shares of common stock in Occidental Petroleum over June 5-7, according to a US securities filing.
Buffett's company bought additional shares in Occidental's common stock for more than $150 million and now owns about 250.6 million shares in the energy producer.
Occidental shares closed at $59.48 on Friday.
As of March, Berkshire owned a roughly 28 per cent stake in Occidental.
Occidental Petroleum previously announced it had entered into a joint venture with Berkshire Hathaway's energy unit to extract lithium in their geothermal facility in California. -Reuters