Warren Buffett is donating more than $1.3 billion of Berkshire Hathaway Inc. shares to four family foundations, disclosing in a letter that he intends to “step up the pace” of his donations while he’s still alive.

The 95-year-old investor, who is stepping down from his role of chief executive officer at the end of the year, also said he will be “going quiet,” meaning that he’ll no longer write Berkshire’s widely-followed annual report or speak at its annual shareholder meeting.