Google Inc revealed on Monday that it had acquired a stake in Chinese community Web site Tianya.cn, indicating a foray by the global search leader into social networking in the world's second-largest Internet market.

A Google spokeswoman confirmed the stake holding by email, but declined to give further details.

Various local media reports on Monday put the estimated size of Google's stake at anywhere from less than 10 percent to up to 60 percent. Other media reports have said Google may be eyeing acquisitions in China.

Google is rushing to close the gap with rival Baidu.com Inc, which dominated the search market in China in the second quarter with a 58.1 percent share, according to research firm Analysys International.

Google followed with a 22.8 percent share and Yahoo China with 11.6 percent, Analysys said.

China is the world's second-largest Internet market after the United States, with around 162 million Web users.

Venture capital investment in Chinese social networking sites has bloomed since Google bought top online video-sharing site YouTube for $1.65 billion late last year.

In another move to diversify its platform in China, Google -- which recently established an engineering research centre in Shanghai -- has also won preliminary approval from Beijing for a license to provide Internet content in the country.

Baidu recently won approval to do its own reporting rather than simply show news search results, while Google is promoting a Chinese-language map search service and online word processing programs. Both are trying to build online library services.

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