The Gates Foundation, which focuses on improving education and health and reducing poverty, received about 15.76 million shares, or 76 per cent of the total donated.
Also receiving donations were the Susan Thompson Buffett Foundation, named for Buffett's late first wife, and the Howard G. Buffett, Sherwood and NoVo Foundations, respectively overseen by his children Howard, Susan and Peter.
Buffett, 84, still owns 18.8 per cent of Berkshire's stock. Forbes magazine on Monday estimated that would give him a net worth exceeding $64 billion, ranking fourth worldwide.
Bill Gates, the Microsoft co-founder, ranked first, at $78.7 billion, Forbes said after US markets closed. Gates is also a Berkshire director, and a close friend and bridge partner of Buffett's.
Most of Buffett's holdings are in Class "A" stock, which gives him 32.9 per cent of Berkshire's voting power.
Buffett typically makes his donations in July, reducing the number of shares by 5 per cent from the prior year. Dollar amounts often rise because of increases in Berkshire's stock price.
The charities typically sell donated shares to finance their activities, reflecting Buffett's desire that the money be spent. Buffett also makes smaller donations to other charities.
Buffett has run Berkshire since 1965. The Omaha, Nebraska-based company has more than 80 businesses in such areas as insurance, railroads, energy and chemicals, and as of March 31 had more than $143 billion of stock and bond investments.
(Reuters)