JUST IN: Warren Buffett has laid out a plan to “step up” the pace of giving away his $149 billion estate to his children’s foundations, while still allowing for a short period that allows Berkshire Hathaway, $BRK.A, shareholders to gain confidence in incoming CEO Greg Abel. “I would like to keep a significant amount of ‘A’ shares until Berkshire shareholders develop the comfort with Greg that Charlie and I long enjoyed,” wrote Buffett. “That level of confidence shouldn’t take long. My children are already 100% behind Greg as are the Berkshire directors,” said Buffett. Buffett owns about $149 billion worth of Berkshire based on shares held at the end of the second quarter.