An agreement by a company controlled by Warren Buffett to take a 10 per cent stake in BYD sent shares of the Chinese electric carmaker and rechargeable battery producer soaring on Monday.

MidAmerican Energy, 87.4 per cent owned by Mr Buffett’s Berkshire Hathaway, will buy 225m shares in the Shenzhen-based company for HK$1.8bn ($230m) at a 4.76 per cent discount to the stock’s closing price of HK$8.4 last Friday.