Deal estimated at $1.6 billion.

Internet search leader Google Inc is in talks to buy popular Web video site YouTube Inc. for close to $1.6 billion, the Wall Street Journal reported on Friday, citing a person familiar with the matter. According to the newspaper, the talks are at a sensitive stage and could break off.

Representatives for Google and YouTube were not immediately available for comment. Separately, Internet blog talked of what it called a completely unsubstantiated rumor of talks between Google and YouTube.

YouTube has quickly ascended to the rank of top Internet video site since it was founded in February 2005 by letting users share homemade video clips.

The site has been a subject of buyout speculation for months since its Chief Executive Chad Hurley was the toast of Allen & Co.'s media mogul retreat in July. Hurley has said in interviews with Reuters and elsewhere that the company was not up for sale.

The site reports serving about 100 million videos daily and has attracted scrutiny from major media companies for pirated versions of copyrighted entertainment appearing on its pages.

YouTube commands a 47 percent share of the online video search market as of September 30, compared with 22 percent for News Corp.'s MySpace video site and 11 percent for Google Video, according to Internet measurement firm HitWise Inc.

YouTube site serves about 32 million unique visitors monthly and has about $11.5 million in venture capital financing from Sequoia Capital.