Windows Phone will become second largest smartphone OS by 2015

Windows Phone operating system is predicted to become the second largest smartphone OS by 2015. The Forecast made by IDC this week promises third place to Apple’s iPhone while BlackBerry will come at the 4th by 2015.

Windows Phone will grow, IDC said, because of the alliance forged between the world's largest mobile phone maker, Nokia, and software powerhouse Microsoft .

First devices from the Nokia-Microsoft alliance are expected to come in 2012.

"By 2015, IDC expects Windows Phone to be the number 2 operating system worldwide behind Android ," Llamas said in a statement.

Making a forecast for the current year the firm says that Android will secure the top spot for all 12 months of the year, after pushing into top territory late in 2010.

Android will secure nearly 40% of the smartphone operating system market in 2011, IDC predicted, and then move to 45% in 2015.

Symbian, Nokia's current OS, will retreat to second place with nearly 21% in 2011, to zero by 2015, since Symbian phones will no longer be produced sometime after 2012.

Windows Phone 7 and WindowsMobile, the older Microsoft OS, will take 5.5% of the market in 2011, but Windows Phone will surge to nearly 21% in 2015, an annual growth rate of 67%, IDC said.