Facebook Inc (NASDAQ:FB) CEO Mark Zuckerberg has donated $1 billion to the Silicon Valley Community Foundation. The nonprofit foundation funds other charitable institutions working in healthcare, education and environment. The Silicon Valley Community Foundation chief executive Emmett Carson told the Wall Street Journal that the organization is pleased to receive another grant from Mark Zuckerberg. However, neither Facebook Inc. (NASDAQ:FB) CEO nor Carson revealed how the latest contribution will be used.

Mark Zuckerberg Facebook

Facebook, its executives sell shares

Facebook Inc. (NASDAQ:FB) said yesterday in an SEC filing that Mark Zuckerberg will donate 18 million of his shares in the social networking giant to the Silicon Valley charity. Based on Thursday’s closing price, those shares are worth $991 million. Facebook Inc. (NASDAQ:FB) added that the company, its CEO Zuckerberg and director Mark Andreessen plan to offload 70 million shares for an estimated $3.85 billion. The social networking giant will sell 27 million shares to raise $1.5 billion. Along with donating 18 million shares, Zuckerberg plans to exercise options on 60 million shares of his company. Then he will sell 41.35 million of those shares, and the majority of the proceeds will be used to satisfy taxes.

Facebook CEO the largest donor to SVCF

In December 2012, Zuckerberg donated 18 million Facebook Inc. (NASDAQ:FB) shares to the same organization. Shares were then valued at $500 million. Earlier this year, he also pledged $100 million to improve the quality of public schools in New Jersey. The Silicon Valley Community Foundation channels charitable contribution by Silicon Valley firms and executives to a number of other organizations. Before Zuckerberg’s latest donation, the foundation had $3.5 billion in assets. Last year, 5% of its grants went to environment-focused charities, 14% for health causes and 40% toward education.

Mark Zuckerberg has signed the Giving Pledge. It’s a movement started by Bill Gates and billionaire investor Warren Buffett to encourage billionaire to donate half their wealth to charity. According to Kirk O. Hanson, a consultant to the Silicon Valley Community Foundation, Zuckerberg is the biggest donor to the organization. The second-largest giver is Jeff Skoll, the first president of eBay Inc. (NASDAQ:EBAY), who has donated $500 million.

Facebook Inc. (NASDAQ:FB) shares were down 0.15% to $54.97 in pre-market trading Friday.