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

Famed investor Warren Buffett is donating $6 billion worth of his company's stock to five foundations, bringing the total he has given to them since 2006 to roughly $60 billion, based on their value when received.

Warren Buffett has given away another $6 billion. The latest philanthropic donation went largely to the Gates Foundation, with the remainder going to charities run by his children. Warren Buffett has given away the biggest chunk of his fortune since he began distributing it in 2006.