Warren Buffett's holding company Berkshire Hathaway has increased its stake in Houston, U.S.-based ... [+] energy company Occidental Petroleum to 28.8%. (Photo: Nati Harnik) Copyright 2018 The Associated Press. All rights reserved. It points to an annualized gain of 7% accompanied by a dividend yield of just under 1.3%. That is hardly anything to get overexcited about. But try telling that to Warren Buffett. The move may be interpreted as Buffett's vote of confidence in traditional energy companies attempti ...