In a transcript of a June court hearing that was closed to the public, lawyers arguing over a legal settlement revealed Facebook's own appraisal had priced its privately held stock at $8.88 per share, giving it a market value of about $3.7 billion.

The Palo Alto-based company relied on the appraisal to value employee stock options fairly and avert possible tax problems.

Facebook, which runs the Internet's largest social network, made the assessment after striking an October 2007 deal with Redmond, Wash.-based Microsoft. As part of a broader advertising partnership with Microsoft, Facebook agreed to sell a 1.6 percent stake to the software maker for $240 million.

The Microsoft investment implied Facebook's stock was worth $35.90 per share — a figure that was relied upon in the settlement of a lawsuit that accused the company's founder, Mark Zuckerberg, of stealing the idea for his online hangout from three former classmates who started another social network called ConnectU.

Facebook spokesman Barry Schnitt declined to comment on any of the figures obtained from the court documents. Microsoft had no immediate comment.

In last June's court hearing, Facebook's lawyers argued the company's appraisal of its common stock couldn't be held up as an apples-to-apples comparison with the Microsoft investment because the software maker bought Series D preferred stock. Microsoft also had an incentive to pay a premium for Facebook's stock because it wanted to deepen its ties to the company's popular Web site, whose worldwide audience of 150 million people could eventually attract billions of dollars in advertising.

Analysts believe Facebook generated somewhere between $250 million and $300 million in revenue last year.

Lawyers opposing Facebook said the company cited the $35.90 per share figure in the settlement negotiations.