China's largest social network, Renren, filed for a U.S. initial public offering to raise up to $573.1 million, the first of a clutch of Facebook clones hoping to boost their profile with an American listing.

Renren, owned by Oak Pacific Interactive, hopes to tap strong appetite for Chinese tech stocks. Online video company Inc, known as China's YouTube, surged 161 percent on its debut late last year, locking in the best first-day returns of an IPO in five years.

China's Internet sector -- the world's largest by users -- is red hot because it is difficult for outside competitors to overcome the political and cultural barriers to operate there, but some analysts warn of a bubble forming.

Renren's website -- sporting some 117 million registered users -- is similar to Facebook's as it allows users to share locations with friends, like something and post updates.

Sources have said that rival social network Kaixin001 also plans to list, but has not gone through the process of selecting banks.

Social networking sites have grown in popularity in China in recent years, gaining most of their revenue from online advertising. They benefit from an ecosystem closed to major foreign competition, with Facebook and Twitter banned in the world's second-largest economy.

But the market is getting increasingly competitive with more than 100 social networking sites operating.

Two social networking sites shut in 2010 due to cash flow issues, local media reported. The industry is also fraught with regulatory and legal risks as China seeks to control the flow of information online.

Renren and some of its shareholders are offering about 52.1 million American Depository Shares (ADS). The company expects the IPO to be priced at between $9 and $11 per ADS.

It intends to list on the New York Stock Exchange under the symbol RENN. Underwriters for the IPO include Morgan Stanley, Deutsche Bank Securities and Credit Suisse.

In the filing, Renren said its website had about 117 million activated users as of March 31, 2011.

Oak Pacific also owns Nuomi, a website featuring daily deals similar to the popular U.S. website Groupon.

In 2010, Renren had revenue of about $76.5 million and a net loss from continuing operations of $61.2 million including some charges.

(Reporting by A. Ananthalakshmi in Bangalore; Editing by Don Sebastian and Tim Dobbyn)