New York, Jan 15 (IANS): After Facebook CEO and his wife making a pledge in December to give away 99 percent of their stock over their lifetime, the social networking giant's COO Sheryl Sandberg has decided to donate $31 million in Facebook stock to charity, the media reported on Friday.

She donated 290,000 shares of Facebook stock at "a market value of roughly $31 million" to various charities, according to a Securities and Exchange Commission document.

The shares were technically transferred to the Sheryl Sandberg Philanthropy Fund.

The majority of the $31 million donation will go to women's empowerment groups and Lean In, a nonprofit founded by Sandberg to help support women in the workplace, recode.net reported.

She also plans to give money to education groups and anti-poverty efforts.

In December, Zuckerberg and Chan promised that they would give away their money "during our lives" through wealth charitable donations, private investment and promotion of government-policy reform.

Meanwhile, Facebook said in a securities filing Zuckerberg has planned to give away "no more than $1 billion of Facebook stock each year for the next three years."