India, June 28 -- Billionaire Warren Buffett donated another$6 billion of Berkshire Hathaway stock to the Gates Foundation and four family charities. The donation made on Friday was his biggest annual donation since he began giving away his fortune nearly two decades ago.

Warren Buffett donated a total of 9.43 million shares to the Gates Foundation and 9,43,384 shares to the Susan Thompson Buffett Foundation, according to a Reuters report. In addition, he donated 6,60,366 shares to charities run by his three children: the Howard G. Buffett Foundation (Howard), the Sherwood Foundation (Susie), and the NoVo Foundation (Peter).

According to Reuters, Warren Buffett still owns 13.8 per cent of Berkshire's stock. Prior to the donations made o...