Microsoft said that various partners will be ready from 6 October with handsets based on the new platform, which was unveiled at the Mobile World Congress show in Barcelona earlier this year.
In Europe, this includes Orange, Vodafone and Deutsche Telekom, with phones supplied by HTC, Acer, LG, Samsung and Sony Ericsson. In North America, the carriers include AT&T, Bell Mobility, Sprint, Telus and Verizon Wireless.
Windows Mobile 6.5 delivers new customer experiences through an improved, easy-to-use interface, better browsing capabilities and access to new services, according to Microsoft.
Among the services built into the new platform are Microsoft's online application store, Windows Marketplace for Mobile, and My Phone, which lets users synchronise data from their phone to a web site, from where it can be accessed with a Windows Live ID.
While Microsoft's platform has lost much of its shine compared to newcomers such as Apple's iPhone and Google's Android platforms, the company is fighting back by trying to stress the familiarity of Windows Mobile for those already running a Windows PC.
Outlook Mobile delivers a familiar, consistent email experience across the PC, phone and browser, according to the firm, while the Office Mobile applications let customers open and edit Word, Excel and PowerPoint documents right from their phone.
"A Windows phone gives people a single phone that works for their whole life, keeping them connected to the people and information they care most about by harnessing the power of the PC, phone and web," said Todd Peters, vice president of Microsoft's Mobile Communications Marketing Group.
Windows Mobile 6.5 also includes an overhauled user interface, and Internet Explorer Mobile has a new engine and built-in Adobe Flash Lite support.