Microsoft Corp. (MSFT) plans a launch this spring of its next-generation operating system for wireless devices, Windows Mobile 6, which is important for the company's efforts to grab market share beyond the desktop.

Microsoft is expected to disclose details of Windows Mobile 6 on Monday at a telecommunications conference in Barcelona, Spain.

The company pledged that the new software would render e-mails and other documents much as they appear on desktop computers. The software also will have deeper connectivity to Microsoft's "Live" suite of online services, including instant messaging.

Those features are part of a broader effort by Microsoft to use connectivity to its prevalent desktop software as a strategy for catching up with the worldwide leader in mobile operating systems, Symbian Ltd.

Microsoft shares were down 12 cents at $29.25 in midday trading on the Nasdaq Stock Market.