Nokia has begun to take a potential Surface Phone from Microsoft rather seriously, according to risks detailed in a SEC filing. The company has bet everything on Windows Phone and many would naturally assume that Stephen Elop and co. made the leap to Microsoft's mobile platform with enough security in-mind. So what's going on to make the company reveal some new threats that weren't noted previously?

Back in its 2011 20F filing, Nokia stated the main threat was that it may not be able to turn a profit by moving from royalty-free Symbian to the royalty-laden Windows Phone. There's a slight change in its 2012 20F filing, which was released on Thursday. Nokia now acknowledges a new risk from the move to Windows Phone: that Microsoft cuts investment in the mobile platform, or completely pulls the plug altogether.

"Microsoft may act independently of us with respect to decisions and communications on that operating system which may have a negative effect on us. Moreover, if Microsoft reduces investment in that operating system or discontinues it, our smartphone strategy would be directly negatively affected by such acts."

As well as the above threats of Microsoft ditching Windows Phone, which seems like a highly unlikely outcome for the moment with the mobile platform fitting in nicely with the company's "three screens" vision, Nokia also touched on the speculation and rumour that Microsoft is broadening its product catalogue by looking into a Microsoft branded Windows Phone Phone. This comes after Elop seemingly welcomed such a smartphone to be released.

"Microsoft may make strategic decisions or changes that may be detrimental to us. For example, in addition to the Surface tablet, Microsoft may broaden its strategy to sell other mobile devices under its own brand, including smartphones. This could lead Microsoft to focus more on their own devices and less on mobile devices of other manufacturers that operate on the Windows Phone platform, including Nokia."

For the time being, Nokia remains the dominant partner for Windows Phone, but in some instances its Lumia brand is becoming recognised more than the platform itself. Microsoft may want to tackle a potential problem with the Windows Phone branding being drowned out. We previously looked at social media activity through Mobile World Congress, which illustrated just how popular Nokia and Lumia were, with Windows Phone and Microsoft way down in the popularity table (but the company wasn't in force at the event).

While Nokia (and HTC) are major partners for Microsoft in the mobile industry, Windows OEM partners have also played a part in further developing the ecosystem, but that failed to prevent Microsoft from launching its own hardware - the two Surface Windows tablets. Of course, the likes of Acer, Dell, HP and Asus cannot be directly compared to Nokia, but it's an interesting trail of thought to engage with.

It's not farfetched to believe that Microsoft is considering a "Plan B", or starting to look at what a Surface Phone would look like as a prototype. If (and that's a fairly big "if") Microsoft does hop into the hardware game with Windows Phone, we'd stand by the notion that the company would likely sell the handsets through its online and physical stores.

Source: SEC, via: ZDNET; thanks to everyone who tipped us!