The six largest U.S. banks may return almost $41 billion to investors in the next 12 months, the most since 2007, as regulators conclude firms have amassed enough capital to withstand another economic shock, Bloomberg News reported yesterday. Lenders, including Citigroup Inc. and Bank of America Corp., will buy back $26.4 billion in shares, up from $23.8 billion, according to the average estimate of three Wall Street analysts. An additional $14.5 billion will be paid out in dividends, $3.4 billion more than 2012, separate estimates show. The payouts are contingent on approval by the Federal Reserve.