CANNES, FRANCE--Nokia and Microsoft set aside an old feud in mobile software today at the GSM World Congress to announce a mobile music service that will span both wireless and wireline networks, and integrate both into the Series 60 and Windows XP platforms.

The new service is geared directly at carriers, which may refuel concerns about both Nokia and Microsoft nosing too far into the content game. But the two vendors tried to allay those worries by promising levels of interoperability and functionality their potential customers haven't seen yet in the market today. To cement the deal, Nokia agreed to make Windows Media Player the standard digital music application on its multimedia phones.

The service, powered by digital music provider Loudeye, will allow customers to browse through thousands of songs on a carrier-branded music portal, and then either download those songs over the air directly to the phone or to their PCs. What's more, users can transfer digital files from their computers to their phones, creating one of the first three-way links for multimedia--PC to handset to Internet.

"Users will be able to transfer music from platform to platform," said Amir Majidimehr, corporate vice president of Windows Digital Media Division. "Our collaboration with Nokia and Loudeye will help remove the islands of content and services we have today and replace them with a seamless digital music experience focused on the consumer."

Nokia multimedia general manager Anssi Vanjoki also had kind words for its handset OS rival, saying any attempt to bridge the PC screen with a handset screen would be practically impossible without Microsoft. "It's hard to find a better cooperation than one with the king of the personal computer, Vanjoki said.

Music download services have been gaining increased attention from carriers since European UMTS carrier 3 revealed the stunning success of its music download service. The carrier sold 10 million digital song downloads within a few months of launch, and carriers worldwide have been looking to replicate that debut. While other music services have been launched in Europe, Asia and the U.S., most have been limited. Either the services offer no over-the-air downloads or only support streaming, or the handsets didn't have the power or memory capabilities to act as digital music players. Nokia and Microsoft's proposed service not only overcome those obstacles, it also has a twist that's completely unique--it's supporting transfer of a customer's music collection to the handset, not requiring that every piece of music heard over the service is purchased from the carrier. The model resembles Apple's popular iTunes service.