Facebook and Google are separately considering a tie-up with Skype, according to anonymous sources.
Web video conferencing service Skype delayed its initial public offering after Facebook CEO Mark Zuckerberg took part in internal discussions about buying Skype, one source told Reuters.
Facebook has reached out to Skype about forming a joint venture, while Google has done the same, according to a second source.
The discussions are in early stages and there is no indication yet which option the companies favour, both sources said.
A Skype deal could be valued at $3-$4 billion and experts expect Skype's IPO to raise about $1 billion.
Although an IPO is still in the cards for the second half of 2011, Skype remains in discussions with other companies, two of the sources said.
If it goes through, a Skype IPO would be one of the most hotly anticipated debuts by a US technology company this year.
A Skype - Facebook partnership would see the social network's user base expand and grow in international markets where the video conference service is popular, while encouraging its half-billion existing users to remain active and connected to the online community.
Facebook can also add another service onto its menu, which is seen as a crucial addition as many mobile devices like smartphones and tablets now come equipped with front-facing cameras.
"It puts Facebook two steps ahead of Google because of the number of Skype users," said Trip Chowdhry, an analyst with Global Equities Research.
"In your social network, you will now have another very compelling service - Skype," he added.
Analysts say that teaming up with Facebook would make more sense for Skype than choosing Google, which already has a similar service - Google Voice.
Skype had about 124 million connected users every month last year, including 8.1 million paying customers who used Skype to make calls to traditional phones at discounted rates.
Analysts have said that while Skype's growth has been impressive, investors would be cautious about its prospects for revenue growth due to the size of its base of nonpaying customers.
Skype, founded in 2003, filed a registration statement to go public last August and chief executive Tony Bates put the eagerly anticipated IPO on hold until the second half of 2011.
Rivals including Apple and Google have made forays into Skype's territory, undercutting its value.
Facebook and Skype would benefit from each other's large community of users but neither has proven revenue models, said a third source.
Skype and Google declined to comment, while Facebook was not immediately available to comment.