Speculation is mounting that the founders of Skype want to buy back their voice over IP business from eBay, with news sources in the US suggesting that they are attempting to raise about $1 billion in equity from private investors to fund the purchase.

According to the New York Times, the Scandinavian founders and now billionaires Niklas Zennstrom and Janus Friis have teamed up with private equity firms KKR, Warburg Pincus, Providence and Elevation Partners to work up a supposed $2 billion bid for Skype.

Today, the Wall Street Journal has dismissed the speculation, saying a deal is unlikely to be completed.

The online auction house bought Skype for $2.6 billion in September 2005 and within two years had to take a massive near $1 billion write-down on the acquired asset.

The rumours about Skype’s ownership follow on the heels of news that the founders of web recommendation site StumbleUpon have successfully bought it back from eBay, taking that company independent again after nearly two years.