The Skype deal would rank at or near the top of the biggest acquisitions in the 36-year history of Microsoft, the WSJ said.
Microsoft and Skype declined to comment to the Journal. Both companies could not be reached for comment by Reuters.
Skype was formed in 2003. Ebay Inc
In 2009, eBay sold a majority stake in Skype to an investor group that included Silver Lake, the Canada Pension Plan Investment Board and Andreessen Horowitz for $1.9 billion in cash and a $125 million note. EBay retained about a third of the company.
Last year, Skype had about 124 million connected users every month by the end of June. But 8.1 million were paying customers, using Skype to make calls to traditional phones at discounted rates.
(Reporting by Sakthi Prasad; Editing by Anshuman Daga)