Investment guru Warren Buffett's Berkshire Hathaway Inc sold US$65 million worth of shares in PetroChina Co Ltd on September 13, marking the fund's fourth reported sale of stock in Asia's top oil and gas producer in two months.

Berkshire sold 45.138 million shares at an average price of HK$11.26 apiece, trimming its stake in PetroChina to 7.99 percent from 8.21 percent of the firm's free-floating shares, according to the Hong Kong stock exchange.