Facebook shares fall as lock-up period expires

Oct 31 (Reuters) - Facebook Inc shares fell 4 percent to $21.07 in busy early trade on Wednesday morning on the company's approval to let employees sell some stock.

The world's largest social network waived a provision that prevented employees from selling shares until Nov. 14. As a result, Facebook staffers were able to sell their vested shares on Oct. 29.

However, because the markets were closed on Monday and Tuesday due to Hurricane Sandy, Wednesday is the first trading day. About 234 million shares held by employees are eligible for sale in the public market.

(Reporting By Jennifer Saba; Editing by Gerald E. McCormick)