Microsoft Corp. is expected to announce a deal with AT&T Wireless Services Inc. Wednesday to sell a variety of wireless software and services to business customers, people familiar with the matter say. The deal could also usher in the U.S. debut of Microsoft software called the " Pocket PC Phone Edition," which runs small, hybrid devices that combine the features of cellphones and Pocket PC handheld computers. The phones, designed by High Tech Computer Corp. of Taiwan and other vendors, are now being sold overseas by British wireless carriers mm02 PLC , a spinoff of BT Group PLC and Vodafone Group PLC . A Microsoft spokeswoman and an AT&T Wireless spokesman both declined to comment on any deal, though Microsoft announced it would hold a conference call Wednesday morning with Chief Executive Steve Ballmer to discuss a "wireless- related business announcement."

Microsoft has lately been striking phone-software deals with wireless carriers, trying to move its core Windows technology onto mobile devices that can do things like cruise the Web and send e-mail. In doing that, Microsoft has put itself in the crosshairs of Finnish phone-maker Nokia Corp., which is trying to develop its own phone software to stave off the Microsoft threat. One of Microsoft 's advantages is that it can link its phone software to ubiquitous programs like Microsoft Office, which many office workers already use to write documents, keep online calendars and send and receive e-mail. Indeed, the AT&T Wireless deal is expected to focus on integrating and manipulating data stored on businesspeople's regular PCs, laptops and phones, so that they can access Microsoft applications anywhere they are. AT&T Wireless already has relationships with about 70% of Fortune 500 companies.