Cisco is trying to buy Skype before it goes public, according to what TechCrunch said Sunday.

The blog hasn't been able to confirm the tale it was told by "one of its more reliable sources," however, Barron's Tech Trader Daily says the rumor is nonsense and that its own personal "source close to Cisco" says there have been no talks between Cisco and Skype.

TechCrunch also claims to have heard that Skype wants to go public for around $5 billion, an indication of what it would cost Cisco. It says Google wants Skype but has an antitrust problem.

eBay still owns 35% of Skype after selling the rest to private equity investors last year for around $2.75 billion.

Skype said in its recent S-1 IPO papers that it had revenues of close to $406 million, up 25%, in the first six months of 2010. Only 8.1 million of its reportedly 560 million registered users are paying anything.