Microsoft Corp has signed up multiple software partners for its upcoming cellphone software marketplace, including Web music service Pandora, game publisher Electronic Arts Inc and social site Facebook.

The software company said on Tuesday it plans to discuss those partnerships and conduct demonstrations of the software store -- set to launch later this year -- at the CTIA wireless showcase in Las Vegas this week.

Apple Inc started the trend for cellphone application stores last summer and its offerings from third- party developers of software, ranging from the practical to the whimsical, have helped boost iPhone sales.

Some analysts are skeptical whether Apple's rivals will be able to generate as much interest from consumers and developers with their own mobile software offerings.

Analysts expect BlackBerry maker Research In Motion Ltd, which popularized email on the go, to officially launch its application store at CTIA. Google Inc already has a store for phones based on its Android system. And Palm Inc is planning one for its Pre phone.

In February, Microsoft revealed plans to open Windows Marketplace for Mobile in the second half of this year, but had not announced software partners until CTIA.

Along with a list of initial partners, the company said it expects many of its existing 20,000 mobile phone software partners to offer software via the marketplace.


Other partners include Gameloft SA, weather website and News Corp's MySpace social networking website. The Windows application for social network Facebook will be the first to let consumers upload video captured on their phones directly to Facebook in April.

The apps marketplace will work on phones based on Windows Mobile 6.5, Microsoft's next version of its mobile operating system, also available later this year. Companies expected to sell phones running Windows Mobile 6.5 include LG Electronics Inc and HTC Corp.

MySpace said LG plans to preload its application onto its new Windows phones in the second half of the year.

In a keynote speech at the show, the president of Microsoft's entertainment and devices unit, Robbie Bach, will announce an alliance with fashion designer Isaac Mizrahi, who will design themes to let consumers customize their phone's appearance.

Microsoft also plans to make its marketplace attractive to carriers with options such as a share of software revenue, 70 percent of which goes to the software developers, according to Andy Lees, who heads Microsoft's Window Mobile division.

We're also partnering with mobile operators very closely so they can have their own stores in the mobile market place, Lees said in an interview ahead of the show.

This would mean that purchases could be included in the consumer's phone bill.

That means we're a very friendly strategy for carriers and for (consumers), Lees said.

He promised strong operator support for the store, but declined to name specific customers.