Nokia, after introducing first its first Microsoft’s windows phone, the company announces to sell continue its legacy Symbian software.

Under a plan announced in February, for the coming over two years, Microsoft’s windows will replace Symbian phones. The announcement raises concern that Nokia could drop Symbian phone that has generated strong profits too early but lost market share.

head of developer relations at Nokia, Purnima Kochikar said in an open letter developers that, “We will be selling (Symbian) devices long after Windows Phone devices from Nokia have already started to appear.”

The company has promised to launch its first Windows phone in early 2012. But they did not announce specific time to continue with Symbian.

According to a research firm Ovum forecast, Nokia’s Symbian phones will be available in the market into 2016.

Kochikar said that the upcoming models of the Symbian would focus on strong integration of services plus they will be equipped with faster processor as well.

She added later, “Over the past weeks we have been evaluating our Symbian roadmap and now feel confident we will have a strong portfolio of new products during our transition period — i.e. 2011 and 2012.”  “They will also include improvements in hardware performance such as GHz+ processing capabilities and faster graphics speeds,” she said.