LinkedIn Corp, a social networking Internet site, on Thursday filed documents with the U.S. regulators for an initial public offering.

The number of shares to be offered and the price range for the offering have not yet been determined, according to the form S-1 registration statement the company filed with the Securities and Exchange Commission.

A portion of the shares will be issued and sold by the company, while a separate portion will be sold by certain stockholders of LinkedIn, the filing said. No specific details were disclosed.

Morgan Stanley, Bank of Americaand JPMorgan are among the book runners for the offering.

LinkedIn had $161.4 million in net revenue with $1.85 million in profit in the first nine months of 2010, according to the filing.

In contrast, Facebook, which has far more users worldwide, had $1.2 billion in revenue in the first nine months of 2010 and $355 million in profit, according to a Goldman Sachs prospectus pitching the company earlier this month to investors.

LinkedIn has 90 million users, compared with Facebook's more than 500 million users.

LinkedIn's investors include Greylock Partners, Bessemer Venture Partners, Goldman Sachs and Sequoia Capital, a venture capital firm that has backed Yahoo, Google, Apple Cisco Systems and Oracle.

(Reporting by Nadia Damouni in New York and Alexei Oreskovic in San Francisco)