Facebook Inc (NASDAQ:FB) director Peter Thiel and Accel Partners, two of the earliest investors of the social network giant decided to sell the majority of their shares after the lock-up period expired last week.

Facebook IPO

Based on Thiel’s regulatory filing, he sold more than 20 million shares of Facebook Inc (NASDAQ:FB), for a total of approximately $396 million at a price range of $19.27 to $20.69 per share, to different entities including Founder’s Fund Management LLC, Rivendell One LLC, and Lembas LLC. Before the expiration of the lock-up, Thiel converted 9.3 million of his Class B shares into Class A shares, a signal that he was preparing to sell a large chunk of his shares in the company. During the Facebook IPO, Thiel sold 16.8 million shares.

Research firm Stifel Nicolaus cited a report from the Associated Press that Microsoft Corporation (NASDAQ:MSFT) sold approximately 6.6 million shares of Facebook Inc (NASDAQ:FB). The research firm said the software giant invested a total of $240 million in the social network giant in 2007. The company already recovered its investment after selling 20 percent of its shares during the IPO for almost $250 million. Microsoft Corporation (NASDAQ:MSFT) still owns 26 million shares of Facebook Inc (NASDAQ:FB) and has no plans of selling the rest of its stakes in the future.

Accel Partners distributed 57.8 million shares to its limited partners, based on its regulatory filing. It is not clear whether its partners sold or kept their holdings in the social network giant. The venture fund held 135.7 million Class A shares and 7.9 million Class B shares after the IPO.

Marc Andreesen, one of the members of Facebook’s board of directors, also submitted a regulatory filing, showing that he received more than 6.5 million shares distributed by Greylock Partners, which holds 29 million Class B shares following the social network giant’s IPO.

The total number of Facebook shares freed from lock-up last week was 271 million. Additionally, 1.2 billion shares will be available for sale in the market during the expiration of the second lock-up period in November.

Facebook investors are uncertain of the company’s capability to generate advertising revenues. During the second quarter, the social networking giant posted a $157 million loss. Since its IPO, the company’s stock value keeps going downward. The company’s shares went as low as $18.75 per share on Monday. The company’s stock is trading at around $19.92 per share on Tuesday morning, August 21.