OMAHA, Neb. (AP) — Billionaire Warren Buffett has given another $3.4 billion of his Berkshire Hathaway stock to five foundations as part of his plan to gradually give away his fortune.

Buffett disclosed the annual gifts Monday. The biggest donation went to the Bill & Melinda Gates Foundation. Buffett also gave stock to his own foundation and to the foundations run by each of his three children.

He converted 11,867 Class A shares of Berkshire stock to 17,800,500 Class B shares, then donated 17,696,780 shares to the five foundations.

Buffett has been giving away blocks of Berkshire stock since 2006. Buffett’s gifts were worth roughly $31 billion based on Berkshire’s share price when the gifts were given.