Warren Buffett-led Berkshire Hathaway has acquired 5.2 million shares of Occidental Petroleum Corp, bringing its stake in the oil company closer to 28 pr cent, according to a regulatory filing on Thursday.

Berkshire purchased the shares between December 19 and December 21 for about $312.1 million, with its stake in Occidental totaling to 27.7 pr cent, a filing with the US Securities and Exchange Commission showed.

Last week, Berkshire Hathaway acquired nearly 10.5 million shares of Occidental for about $588.7 million after the company agreed to buy US shale oil producer CrownRock in a $12 billion deal.