Microsoft will unveil a lineup of smartphones using its upgraded mobile operating system on 11 October in New York, according to a Wall Street Journal (WSJ) report.

The WSJ quoted people familiar with the launch plans as saying that following the launch, AT&T will begin offering new smartphones in four weeks.

AT&T will provide marketing support to Microsoft by becoming the initial exclusive US carrier to sell the Windows Phone 7 smartphones, and initially offer three handsets – one each made by Samsung Electronics, LG Electronics, and HTC – in an effort to diversify its mobile devices portfolio beyond the iPhone. LG and HTC have a much larger presence in Android.

It was evident from the market response that the emergence of Apple iPhone in 2007 forced other smartphone platforms to step up activities and left Microsoft behind as it failed to update its software to the level of iPhone, as far as many observers were concerned.

According to a Gartner report, Microsoft’s share of the smartphone operating system market dropped from 9.3% in 2008 to 5% last year.

Inspired by the experience of its Zune portable media player, Windows Phone 7 represents Microsoft’s chance to start over with a new platform to build a presence in the already burgoing smartphone market, the WSJ said.