That's according to report by Business Insider, which claims both parties are looking to collaborate on a handset designed to play the built-in Facebook tools sported by Microsoft's OS.
Microsoft 'likes' this
No official source has confirmed the rumour Business Insider instead suggesting several unnamed sources have described a partnership between the companies as "plausible, logical, and even likely" - though some sort of agreement wouldn't come out of the blue.
Microsoft invested in Facebook six years ago a move now likely to generate more than $1 billion for the firm while the social network recently purchased $550 million worth of patents from the Redmond giant.
Commentators have also been quick to point out that the two companies share notable rivals, namely in the form of Google.
An eye on Android?
Indeed, speculation had previously suggested Facebook would look to deliver a smartphone based on the Android platform, albeit in a highly altered form.
Windows Phone's built-in Facebook compatibility, however, means there would only need to be minimal changes to the OS to support a Facebook branded device.
