Warren Buffett, chairman of Berkshire Hathaway Inc., right, and Bill Gates, chairman and co-founder of Microsoft Corp., participate in a newspaper toss event at the Berkshire Hathaway annual shareholders meeting on Saturday, May 5, 2012.

Warren Buffett said he will donate $3.6 billion worth of Berkshire Hathaway shares to five foundations, including the Bill & Melinda Gates Foundation.

The Oracle of Omaha will convert 11,250 of his Class A shares into 16.875 million Class B shares. About 16.8 million of these Class B shares will be donated to five foundations: Bill & Melinda Gates Foundation, Susan Thompson Buffett Foundation, Sherwood Foundation, Howard G. Buffett Foundation and NoVo Foundation, the company said in a statement on Monday.

Buffett pledged in a 2006 letter to make annual gifts of Berkshire B shares throughout his lifetime for the benefit of the Bill & Melinda Gates Foundation. He donated $1.5 billion worth of shares that year.

Berkshire said Buffett has never sold any shares of Berkshire, and about 45% of his 2006 holdings have been given to the five foundations, totaling about $34 billion.