NEW YORK (Reuters) Facebook is preparing to file for an initial public offering as early as October or November that could value the popular social networking site at more than $100 billion, financial news channel CNBC reported on Monday.Goldman Sachs is leading the chase to manage the lucrative offering, which could come in the first quarter of 2012, CNBC said.With more than 500 million users, Facebook is the world’s most popular internet social network and one of the most hotly-anticipated initial public offerings on Wall Street.Facebook, whose chief operating officer last month told Reuters that an IPO was “inevitable”, declined to comment on the latest report about its timing for an offering.Anticipation about a Facebook’s future plans comes at a time of heightened investor appetite for shares of fast-growing social networking companies.Professional networking site LinkedIn Corp launched its own IPO last month, valuing the company at about $7 billion. Earlier this month, daily deals site Groupon Inc filed to raise up to $750 million in an IPO, fuelling speculation that internet valuations have become too rich.Founded in a Harvard dorm room in 2004 by the now 27-year-old Mark Zuckerberg (pictured), Facebook threatens internet companies like Google Inc and Yahoo Inc as it becomes a popular online destination for web surfers and an important marketing channel for advertisers.Facebook was valued at $50 billion earlier this year when Goldman Sachs invested in the company.Recent transactions of Facebook shares on the secondary market have valued the company between $78 billion and $81 billion, according to information on the website of Sharespost, an exchange for trading shares in private companies.Facebook is expected to generate roughly $4 billion in advertising revenue in 2011, up from $1.86 billion a year earlier, according to market research firm eMarketer.