Facebook Inc., in its first stock offering since going public last year, said the company and stakeholders are selling $3.85 billion worth of shares.

Facebook priced 70 million shares at $55.05 apiece, according to a statement today. About 27 million will be offered by the company, with an additional 41.35 million 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 1.65 million shares.

Facebook slipped in extended trading to $55.07 after closing at $55.12. 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 Dec. 20, it plans to include Facebook’s Class A common stock in the S&P 500 Index.