It also launched four new models it calls "quick messaging devices." They include Pantech's Reveal and Impact, as well as Samsung's Mythic and Flight.

AT&T didn't announce full details for all six new phones, but said the HTC Pure is now available at AT&T stores for $150 after rebates, and the HTC Tilt 2 will cost $300 after rebates. Both require a smartphone data plan commitment and a $40 or higher voice plan in order to receive the rebates.

The HTC Pure is a touch-screen device, while the Tilt 2 combines a tilting touchscreen with a slide-out full QWERTY keyboard. Both offer a user interface that gives access to voice, text or e-mail by viewing a single contact.

AT&T said that with the launch it was one of the first carriers to offer Windows Mobile 6.5 devices. Microsoft's mobile OS has come under some criticism from some analysts and even Microsoft Corp. CEO Steve Ballmer, who recently said he reorganized the entire Windows Mobile team.

However, analysis firm iSuppli Corp. recently issued a strong forecast for Windows Mobile, taking note of its use by HTC and projecting its use on smartphones will nearly triple by 2013.

AT&T's vice president of mobile phones, Michael Woodward, said in a statement that the Tilt 2 and Pure "will lead our Windows phone lineup into 2010," and noted that "AT&T has a long history of leadership in smartphones and Windows Mobile." He said AT&T is the largest distributor of Windows Mobile phones worldwide.