Biz Stone, co-founder of popular microblogging site Twitter, denied a report that the company was in talks to sell a $450 million stake to a JPMorgan fund, reiterating that it was committed to remaining independent.

A JPMorgan Chase & Co fund was in talks to acquire 10 percent of Twitter for $450 million, valuing the company, which has 350 employees, at $4.5 billion, the Financial Times reported on Sunday.

(The report is) made up, Stone told Reuters in Seoul on the sidelines of a forum organized by broadcaster MBN.

Twitter, which allows users to send short, 140-character text messages, or Tweets, to groups of followers, is one of the Web's most popular social networking services, along with Facebook and LinkedIn.

Social networking services are presenting a growing challenge to established Web players such as Google Inc, Microsoft Corp and Yahoo! Inc, competing for users online and for advertising dollars, raising speculation that Twitter may become the target of a takeover bid.

Google and Facebook have held low-level takeover talks with Twitter that give the Internet sensation a value as high as $10 billion, the Wall Street Journal reported last month.

Stone said Twitter wanted to remain independent and was not in formal bid talks.

The company held talks with Facebook a couple of years ago ... (but) nothing formal since and it's mostly rumors all the time, he said.

Stone, who reportedly pronounced his given name Christopher as Bizober when he was learning to talk and decided to abbreviate it later to Biz, created Twitter with Evan Williams and Jack Dorsey in 2006.

He left Google at around the same time with Williams to start a new podcasting project and later worked to improve the then-popular text message to create Twitter.

It has since become a popular communication tool for celebrities, politicians and businesses, and has played a role in several geopolitical events such as the 2009 post-election demonstrations in Iran.

We make money. We earn money from a suite of products -- We have promoted tweets ... promoted accounts, all of which are in our advertising mechanism.

We are just really getting started. We have some internal forecasts (for advertising revenue for 2011) but nothing is really shared right now. We don't need to set the world record or anything like that.

Industry research firm eMarketer said in January that Twitter, which does not disclose financial information, generated an estimated $45 million from advertising in 2010 and was expected to generate about $150 million this year.

(Reporting by Miyoung Kim and Ju-min Park; Editing by Chris Lewis)

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