• by Gavin O'Malley  @mp_gavin, January 28, 2011

After years of build-up, LinkedIn has finally filed to go public at a likely valuation of $2 billion. The social-networking site for professionals is hoping to raise up to $175 million to scale its business and develop new services.

Opening its books as part of the IPO process, LinkedIn revealed that net revenue nearly doubled to $161.4 million in the first nine months of 2010 -- up from $80.8 million in 2009 -- with $1.85 million in profit.

LinkedIn said it is now profitable, with net income of $10.1 million -- up from a loss of $3.38 million during the first nine months of 2009.

According to the company, 41% of its revenue presently comes from job-related products that help companies search for potential employees; 32% comes from ad sales; and the remaining 27% comes from paid subscriptions.

Already, LinkedIn says it has $89.6 million in cash and cash equivalents on hand.

Yet its niche market is evolving quickly as it faced increasing competition from smaller international rivals, like Xing in Germany and Viadeo in France. It's also widely believed that LinkedIn is wise to go public before Facebook -- which, even without an IPO, represents an existential threat to any social network on the Web.

Along with potential acquisitions, LinkedIn said the additional funds are needed "for general corporate purposes, including working capital, sales and marketing activities, general and administrative matters and capital expenditures."

In its filing with the SEC, LinkedIn added: "We believe that our members and the enterprises and professional organizations that use our platform are only beginning to leverage the power and potential of our network and its underlying database of professional information."

To date, acquisitions include personalization startup mSpoke and ChoiceVendor, which rates and reviews business service providers, for which it paid $736,000 and $4.989 million, respectively. LinkedIn's registered membership increased almost two-thirds to 90 million last year -- up from 55 million users in 2009. So far, the company has raised over $80 million, including $53 million in a key financing round led by Bain Capital in mid-2008.