The internet phone firm is looking at its options but some observers think it makes more sense for Facebook to buy it

A source told Reuters  that an outright buyout of Skype could value the company at between $3 billion and $4 billion.

Three months ago Skype delayed its IPO, which it was believed would raise $1 billion after former Cisco executive Tony Bates was hired as CEO.

Skype was originally bought by eBay in 2005, for $2.6 billion. The idea was to integrate the phone firm into the auction and PayPal businesses - but that never quite worked out and in 2009 the company sold 65 percent of its stake for $1.9 billion to a consortium  led by private equity firm Silver Lake.

One commentator said it was natural that Silver Lake should now be looking to sell out. But there was puzzlement why Google would want to buy Skype, other than to simply deny it to Facebook. Google already has its own internet phone service, tied into into Gmail and Google Voice.

In the case of Facebook, the attraction is clearer. Voice communication is one thing the giant social network does not have . The members want it - and Facebook has the money to buy it.

Skype is currently gaining hundreds of thousands of new users each week and now has 505 million members - roughly the same as  Facebook.

All of the discussions are in “early stages,” according to Reuters.

No-one in the three companies would say anything.