Microsoft Corp.'s Silverlight media player will be made available on mobile phones using Nokia Corp. software, the companies announced on Tuesday.

Microsoft is developing a version of Silverlight, the media player it unveiled for PCs in April last year, for Nokia's Symbian mobile phone operating system. It will run on Nokia smartphones that use the newer S60 version of Symbian, as well as older ones using the S40 version, Microsoft said.

The company is also working on a version of Silverlight that will work on smartphones that use its own Windows Mobile platform.

Industry analysts said Microsoft likely decided to develop Silverlight for Nokia first because the handset maker's Symbian is the dominant system on smartphones in terms of market share.

Nokia shipped about 53 per cent of the 35.5 million smartphones sent out in the fourth quarter of 2007, according to estimates from market research firm Canalys Ltd. Research In Motion Ltd., maker of the BlackBerry, by comparison had only 11 per cent market share.

Silverlight is a challenger to Adobe's Flash, which is used by many popular websites including YouTube. The two players now appear to be headed for a showdown on both the regular web and the mobile internet, as Adobe signed a similar deal with Nokia last fall for a Flash Lite player.

Adobe said at the time that Flash Lite had shipped on more than 300 million phones.