Nokia reported an increase in sales for the first quarter, but profit declined. The company expects a challenging second quarter as it bears the full brunt of component shortages resulting from the earthquake in Japan. Nokia and Microsoft have signed a definitive agreement to move to Microsoft’s Windows Phone as its main smartphone operating system. Nokia’s overall market share dropped from 41 percent to 26 percent, according to preliminary estimates from Nokia. Nokia also plans to launch its own application store, where developers will be able to sell apps for Windows Phone devices.”]