The company is working on software to allow devices that use Windows Mobile to connect to a corporate IM server running Microsoft's Live Communications Server 2005, Microsoft said on Monday.
In addition, rival Research In Motion plans to develop messaging software for devices that link to servers using software from both RIM and Microsoft. Other partners are building Microsoft-compatible instant-messaging clients that will run on mobile gadgets using the Palm or the Symbian operating system.
The Redmond, Wash.-based software giant said customers have been asking it to move its business messaging software beyond the PC.
"People are saying we really need this to be integrated with our mobile devices," Ed Simnett, group product manager at Microsoft, said.
BlackBerry maker RIM may actually be first out of the gate with its software. RIM said its product will ship by year's end, while Microsoft said it is only aiming for a beta, or test version, this year. Simnett declined to say when the final version of Microsoft's application will ship.
"Typically that would follow some months" after the beta, Simnett said. "It's unlikely to be this calendar year."
The Microsoft software is planned to run on phones and Pocket PC handheld devices that are running either Windows Mobile 2003 Second Edition or on the forthcoming Windows Mobile 5 software, also known by the code-name Magneto.
The RIM deal is the latest in a series of arrangements that links Microsoft with its mobile rivals in one way or another. For example, Microsoft is, which makes an operating system that competes with Windows Mobile. Microsoft has to hardware maker PalmOne, which has historically used the Palm operating system.
RIM's BlackBerry Enterprise Server software remains a competitor to ActiveSync. But with this deal, Microsoft is saying that even if customers use a rival means of connecting to Microsoft e-mail systems, it wants them to use its instant-messaging servers. In many cases, BlackBerry's server software is already working with Microsoft-based hardware, providing mobile access to e-mail and other data stored on a Microsoft Exchange server.