Google Inc. co-founder Sergey Brin said on Thursday his company would be happy to talk with Facebook about potential ties, but that the social network did not appear to be courting takeover bids.

If they come to us, we'd certainly be open to talking, Brin said, answering a reporter's question at the 25th annual Allen & Co. media deal-makers conference in Sun Valley, Idaho. But I think they're building a great company of their own.

Facebook membership has exploded in recent weeks to more than 29 million active members from 24 million in late May. By comparison, rival MySpace has attracted about 60 million unique users in the United States and about 90 million globally.

Deal speculation has followed Facebook, a college-student sensation that has now turned itself into an all-ages site. Last year, Google rival Yahoo Inc. was ready to pay some $900 million for Facebook, according to sources familiar with the situation.

Palo Alto, California-based Facebook was founded in 2004 by then-undergraduate student Mark Zuckerberg as a social meeting site for fellow students at Harvard University, but it has seen its usage spike since it opened up in May to anyone.

Zuckerberg has said repeatedly he is committed to building an independent company. He reiterated this position in May when he announced the plans to open up the platform to other software developers, who can build applications on the site.

I already thought Facebook should remain independent. This (announcement) just strengthens that, he said.

Sources close to the company say moves to bolster its management team and put its finances on a firmer footing through experiments with advertising sales are aimed at preparing Facebook for a potential initial public offering over time, although no specific plan has been set.

Many Silicon Valley observers also consider Microsoft Corp. a potential bidder if Facebook were put up for sale. Microsoft supplies advertising services to Facebook and is hungry to expand its Web presence to compete with Google.

Max Levchin, chief executive of Slide.com, the most popular maker of mini-applications known as widgets, said Facebook has borrowed many elements of Microsoft's decades-old strategy of serving as a platform for independent software makers.

I would be amazed if they weren't trying to get their hands on Facebook, he said in an interview this week, referring to Microsoft. The whole platform play is so obvious.

Levchin was co-founder of online payments company PayPal, which was sold to eBay Inc. in 2002.

The attention paid to Facebook has even eclipsed MySpace. It was MySpace's own rapid growth that helped make Rupert Murdoch a Wall Street darling. Bought by News Corp. in 2005 for $580 million, it is now considered worth about $10 billion by some Wall Street analysts.

Asked if the rise of social networks has had a negative impact on Google, Brin said, Social networks are creating lots and lots of content ... and that's more for us to search.

(Additional reporting by Eric Auchard in San Francisco)

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