LinkedIn, the social networking site for professionals, plans to go public in 2011 and has selected its financial underwriters, three sources familiar with the process told Reuters.

Morgan Stanley, Bank of America and JPMorgan are among the book runners, these sources said. Bankers made their pitches to the privately-held company in November, one of the sources said.

An IPO is just one of many tactics that we could consider, a spokesman for LinkedIn said on Wednesday. He declined further comment.

Internet companies such as LinkedIn and Zynga, a popular maker of online social games, are considering offerings well ahead of a potential IPO of Facebook, two sources said.

Some of these companies want to go public because they want to beat Facebook and others out, said one of the sources. If Facebook went public before Linkedin, do you think anyone would pay that much attention to Linkedin? You might want to surpass the beast.

Zynga couldn't be reached immediately for comment.

Facebook is not expected to file for a public offering until late 2012, Facebook board member Peter Thiel told Reuters in September.

But that could change. Regulators are scrutinizing a $500 million investment and a commitment to raise at least $1 billion more in Facebook this week by Goldman Sachs and Digital Sky Technologies, one of the sources said.

The SEC is reviewing whether the number of shareholders in Facebook has exceeded a 499 limit in order to remain private. If the SEC decided Facebook has moved past the threshold, it could accelerate Facebook's timeline for an offering, the source said.

Facebook and Goldman have declined to comment.

The people familiar with the process said LinkedIn is hoping to attract investors on its reputation as one of the Web's fastest growing social network sites.

The site claims more than 85 million members.

The filing of LinkedIn's S-1 registration statement with the U.S. Securities and Exchange Commission, which contains the basic financial information of an issuer, could take months, said one of the sources.

There are lots of things that are worked on that they could put on hold; they miss numbers; they want to grow a little more, another of the sources said.

Linkedin, which does not disclose financial results, makes money from advertising and premium services. The valuation of a Linkedin IPO was not given by the sources.

Sales of its stock on online secondary market exchange SharesPost gives LinkedIn an implied valuation of around $2.2 billion.

In an interview with Reuters in September, Chief Executive Jeff Weiner said the company has had discussions with bankers, but wouldn't characterize it as being specific about discussing IPOs. He said that such conversations have occurred since he joined the company as interim president in early 2009.

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

(Reporting by Nadia Damouni; Editing by Kenneth Li and Carol Bishopric)