Shipping figures are in line with Google and Amazon's Nexus 7 and Kindle Fire tablets.
Microsoft is instilling enough confidence into its Surface tablet that it has commenced a "large volume production" of the device, which may see up to 5 million units being shipped during the fourth quarter.
According to component supplier sources in Asia, the Wall Street Journal said Microsoft will build between 3 million and 5 million Surface tablets before 2013 arrives.
Sources suggest that Microsoft's figures are in line with both Amazon and Google for their Kindle Fire and Nexus 7 tablets, respectively.
Back in August, IDC analyst Bob O'Donnell told CNET that he expects Microsoft to produce "a little more than 3 million Surface tablets" before the coveted Christmas holiday season arrives.
As for Microsoft's expectations of Surface's commercial performance, chief executive Steve Ballmer had said it hopes to sell "a few million" over the next 12 months.
Microsoft recently unveiled the long-awaited prices announcement for Surface, which launches alongside Windows 8 come October 26.