By Joia Shillingford
BBC News business reporter at the 3GSM World Congress in Cannes
Nokia has announced a tie-up with software giant Microsoft and US music download service Loudeye.
The mobile phone industry is gathering in Cannes
Users will be able to download songs and ringtones to Nokia handsets equipped with Microsoft's digital music-playing software.
There will be a choice of tracks from international and local music lists.
Microsoft, which competes with Nokia in developing mobile phone operating software, will see its Windows Media technology installed on Nokia phones.
Nokia made the announcement at the 3GSM World Congress mobile phone trade fair in Cannes.
In a major about turn that will widen the market for its phones, Nokia also signalled it was willing to allow co-branding on handsets and to co-operate more with mobile operators.
"We have intensified our dialogue with operators...we have put our attentive ear to work like never before," said Olli-Pekka Kallasvuo, executive vice president for mobile phones at Nokia.
Nokia unveiled three new phones at the show, including the 6681 which features a high-end music player with stereo output and a new software application.
Sony Ericsson, meanswhile, announced it will sell music-playing mobiles under its Walkman brand and will work closely with Sony Connect and Sony BMG, its music division, on content.
And UK mobile phone maker Sendo unveiled its digital music player/phone, the X2.
Sendo described the X2 as the "first phone that makes playing music truly as simple as making a call".
The Sendo handset - which also has a 1.3 megapixel camera - automatically pauses the music when a phone call is received.
It has a built 32Mb memory but its capacity is expandable to up to 1Gb with a miniSD card, making it an alternative to stand-alone digital music players.
The Sendo announcement was made at a morning Nokia press conference at which the Finnish mobile maker announced the third edition of its Series 60 operating system.
Sendo phones have been using Nokia's industry-backed Symbian operating system.
The new edition of Series 60 will be used on smartphones, including the X2 and a phone for the Chinese market from China's Lenovo, in conjunction with Symbian.
Antti Vasara, vice president of mobile software sales and marketing at Nokia, said the next version of Series 60 would provide more support for different types of phones.
It will also include built-in features to support music, digital rights management, cameras, mobile gaming, and location and web services.
Mr Vasara said Series 60 will allow mobile operators and handset makers to customise the user interface on phones as well as other features of the operating system.
"What we are targeting, is to be the best platform for operator customisation," he said.
Nokia estimates that the global smartphone market will exceed 50 million units in 2005. By 2008, it estimates smartphones will account for a quarter of the total mobile device market.
The Series 60 3rd Edition runs on version 9.0 of the Symbian operating system. It will be available to licensees in mid-2005.
Mobile applications written for older versions of Series 60 will have to migrate to the new platform.