A total of about 777 million more shares of the social networking giant, Facebook are set to available from Wednesday as lock-in period concludes.

From Wednesday, the company's employees will be able to sell their shares and generate income. These shares will be in additional to the 1.3 billion shares of Facebook that are already trading on the stock exchange. The company has a total of 2.2 billion shares outstanding.

Investors have been concerned over the selling of shares by employees since Facebook went public on May 18. Employees, officers and early investors are generally restricted with a lock-in period to avoid overselling and putting pressure on share prices.

Investors and the company is concerned due to the impact of earlier lock-in periods on the share prices. When the first lock-in period concluded, the shares of the company had fallen 6 per cent to $19.87 and when the when the second lock-in period finished, the shares fell by 3 per cent.

However, some indicate that the lockup has been known to all and large investors are looking to pick up shares at the price range of $18.50 a share. The price changes will depend on more or fewer employees than expected sell their shares in the country.