• PC World
• »Phones

Sony Ericsson will begin selling its first phone using Windows Mobile software this year, Microsoft is due to announce on Sunday, just ahead of the Mobile World Congress in Barcelona.

Until now, Sony Ericsson has primarily used the Symbian operating system to power its smart phones. Its Windows Mobile phone will have a touch screen with a slide-out keyboard and a camera, said Brian Arbogast, vice president of mobile services at Microsoft.

While Apple's iPhone has spurred wider interest in touch-screen phones, Sony Ericsson has been selling touch-screen phones for years. It uses the UIQ user interface on its Symbian phones. UIQ competes with Series 60, the user interface Nokia developed to run on its Symbian phones.

Sony Ericsson joins HTC, Motorola, Palm, Samsung and others selling phones that use Windows Mobile.

Microsoft said the Sony Ericsson device should be available to end-users this year, and that examples of it will be on display at the conference in Barcelona. Sony Ericsson was not available to offer more details. It has scheduled a conference call Monday to discuss the announcement.

"We're excited about them bringing their entertainment expertise and experience and brand to a device that has all the benefits of Windows Mobile," Arbogast said.

Sticking With Symbian

Sony Ericsson will likely continue to sell Symbian phones in addition to the Windows Mobile handset, a common practice among mobile-phone developers. For example, Motorola sells Windows Mobile, Symbian and Linux phones, while Palm sells Windows Mobile phones as well as handsets that use its own operating system.

Nokia, the number-one handset maker in the world, does not make Windows Mobile phones, but it uses Linux to power handheld computers, in addition to its wide use of Symbian.

The Sony Ericsson phones could help Microsoft further a recent effort to position Windows Mobile phones, which are primarily seen as tools for business users and attractive to consumers. Sony Ericsson makes phones with its Walkman music players and Cybershot cameras, featuring brands that are well-known to consumers.

Rumors circulated late last year that the handset maker had begun manufacturing a Windows Mobile phone that would ship in the second half of this year. At the time, Sony Ericsson would not confirm the plans.

Windows Mobile is in a distant second place behind Symbian in market share among mobile operating systems. In the fourth quarter 2007, Symbian was used in 65 percent of smart phones sold worldwide, according to recent research from Canalys. Microsoft had 12 percent of phones sold, followed by Research In Motion with 11 percent.

The Mobile World Congress, formerly called 3GSM, starts Monday in Barcelona.