The Bill & Melinda Gates Foundation just got a $1.5 billion infusion.

Warren Buffet, the third-richest person in the world, gave 19.34 million shares of his insurance and investment company, Berkshire Hathaway Inc., to the charitable organization, which was created by Microsoft co-founder Bill Gates and his wife to help address the world's education, health and poverty problems.

Buffett, 80, donates smaller sums at about the same time every year to four family charities, including the Susan Thompson Buffett Foundation, named for his late first wife, and foundations for his three children.

In 2006, Buffet pledged to give away 99 percent of his wealth, which is estimated at $50 billion. Thus far, he has donated $9.5 billion to the Gates Foundation, which employs 927 people, spent $2.6 billion in 2010, and has a $37.1 billion endowment.

[Yahoo!]