Warren Buffett's Berkshire Hathaway Inc BRK BRK has been steadily trimming its stake in Bank of America Corp BAC, selling off $7.2 billion worth of shares since mid-July.Warren Buffet Has Been Trimming Stake In BACFollowing the sale of 5.8 million shares for$228.7 million at an average price of $39.45 on Friday, Monday and Tuesday, Berkshire Hathaway's stake in Bank of America has decreased to approximately 11% of the company's total shares. Despite this reduction, Berkshire remains BAC's largest sharehold ...