With the platform burning, Nokia also talked to RIM before jumping into Redmond's arms

The battle of mobile ecosystems is now a three horse race: Apple’s iOS, Google’s Android, and Microsoft’s Windows Phone. Or so says Nokia CEO Stephen Elop now that the Finnish handset maker has jumped off of a burning platform into Redmond’s arms.

Conspicuous by their absence – in Elop’s analysis – was RIM’s BlackBerry or indeed the dark horse in the room, HP’s webOS. They are both, of course, vertical platforms (as is iOS) so you’d be forgiven for thinking that licensing either was never a consideration. However, TechCrunch Europe has learned that Nokia did indeed explore a partnership with RIM, which would have seen Nokia smartphones running BlackBerry OS.

According to our well-placed sources, discussions between the two companies took place as Nokia in parallel explored the Google and Microsoft options. How far those discussions went isn’t entirely clear, although our source says that RIM wasn’t interested, but either way the fact that they took place at all is intriguing in itself. Not least because Elop has since attempted to airbrush out RIM’s place in the competitive landscape.

We’ve also learned that as Nokia explored adopting Android with Google it was the “commodization risk“, as Elop has since described it, that turned out to be the deal-breaker. Specifically, Nokia wanted to replace Google Maps with its own Ovi offering, along with changes to Android’s handling of email, contacts, calendar, app-store and over-the-air software management in an effort to stop value moving entirely to Google – to which the search giant said no. Unless, that is, Nokia wanted to fork Android completely and therefore “stay behind the curve.”

That was never seen as a viable option, says our source, whereas the Microsoft tie-in will see Nokia having direct input into Windows Phone’s future development roadmap and its Ovi Maps and broader location layer being integrated into the platform. It’s also worth remembering that Microsoft Bing already gets its maps from Nokia’s Navteq.

That said, just as going with Google or indeed RIM would have signaled, by adopting Windows Phone, Elop has decided that Nokia should no longer be in the software game or certainly at the OS-level. Once that decision was made, says our source, it was just a matter of picking which platform to go with.

Of course, the knock on effect will be a massive reduction in software engineering and R&D head count as the company attempts to reduce spending on Symbian and MeeGo to near zero for 2012. Our source also says that Nokia’s Windows Phone software integration will be done in the U.S., which would appear to be in-line with earlier reports of a bigger Silicon Valley presence.