Warren Buffett donates $3.6bn to Gates' and family charities

Donation is biggest in billionaire’s plan to give away fortuneBill & Melinda Gates Foundation receives 80% of shares giftWarren Buffett is donating roughly $3.6bn of Berkshire Hathaway stock to five charities including the Bill & Melinda Gates Foundation, the biggest contribution in Buffett’s plan to give away his fortune.Berkshire said Buffett’s 14th annual donation comprises about 16.81m class B shares of Berkshire. Related: Warren Buffett says Republican tax cut 'del