Facebook Inc, in its first stock offering since going public last year, said the company and stakeholders are selling $3.85bn worth of shares, Bloomberg reported.Facebook priced 70mn shares at $55.05 apiece, according to a statement on Friday. About 27mn will be offered by the company, with an additional 41.35mn by chief executive officer Mark Zuckerberg, who will use most of the cash to pay taxes incurred from exercising options.The sale coincides with Facebook’s inclusion in the Standard & Poor’s 500 Index, an event that triggers demand from index funds and other institutions that need to purchase the stock. Facebook said it will use the proceeds for working capital and other corporate purposes. Marc Andreessen, a Facebook board member, is also selling 1.65mn shares.Facebook closed unchanged at $55.05 in New York on Friday. The stock has more than doubled this year, rebounding from its troubled debut in May 2012 that wiped away half the company’s market value in its first three months on the market.S&P had announced that as of the close of trading on December 20, it plans to include Facebook’s Class A common stock in the S&P 500 Index.Zuckerberg is separately donating 18mn shares on December 31, according to a filing on December 19. Those shares, currently valued at $992mn, are being given to the Silicon Valley Community Foundation, according to a person with knowledge of the matter, who asked not to be identified because the information is private.Vanessa Chan, a spokeswoman for Facebook, declined to comment. Sue McAllister, a spokeswoman for the Silicon Valley Community Foundation, didn’t respond to a request for comment.The charity donation plus his share sale accounts for more than 10% of Zuckerberg’s Facebook holdings. Along with a stock sale for tax purposes and a charity contribution last year, the CEO has sold or gifted about 20% of his Facebook stake.Zuckerberg is the 22nd-richest person in the world, according to the Bloomberg Billionaires Index, with a net worth of $26.9bn.