Finland's Nokia Oyj. (HEL:NOK1V) is the world's largest smartphone maker.  Nokia also has a very big problem.

The company recently tied the knot with Microsoft Corp. (MSFT), promising to phase out its proprietary Symbian smartphone operating system for Microsoft's slick new Windows Phone 7 OS.  The company insisted that the move had nothing to do with the fact that an ex-Microsoft Canada executive recently became Nokia CEO.

Regardless of the move's origins the question quickly became when would the switch to Windows Phone 7 be made?  Nokia has opted for a "gradual" transition in which it slowly phases out the operating system.  At the same time it will release Windows Phone 7 handsets, which will live side by side with Symbian handsets.

The approach has its merits, when looked at from a certain perspective.  But Nokia badly underestimated a major issue raised -- nobody will want a phone on a dying platform.

According to reports Nokia's market share loss has accelerated from a slow bleed to a pouring stream.  

Signs of this have crept up in recent financial filings.  Nokia has lowered its Q2 2011 outlook[press release] for devices and services.  It went from predicting 6.6B € ($9.5B USD) to 6.1B € ($8.8B USD).  That's a big drop.  The drop is fueled by lower predicted volumes -- which seem to be stemming from poorer than expected Symbian smart phone sales.

At the same time the company's operating margins have dipped from a predicted 6 to 9 percent to "around breakeven."

Annual targets are also being scaled back.

If there's one ray of sunshine among the storm clouds it's that Nokia reports an "increased confidence" level that it will deliver Windows Phone 7 handset(s) by Q4 2011.

The question, though, is whether that will be too late.  For now Nokia will have to continue trying to pitch customers a dying platform -- Symbian.  Nokia predicted sales of 150 million more Symbian smartphones "in years to come."  Now, as customers defect to Apple, Inc. (AAPL), Research in Motion Ltd. (RIM), and Google Inc.'s (GOOG) Android, it seems like a matter of time before that number becomes the latest financial figure to be slashed at the Nokia headquarters.