China Unicom NewSpace, part of the country's second-largest operator, after GSM-based China Mobile, will launch the CU928 multimedia phone on its U-Web CDMA 1x-based service.
The device is a mix of a PDA and cellular handset, using dual chips and the Pocket PC Phone edition of the OS. An Intel PAX265 400MHz processor looks after the PDA part while a Qualcomm MM5500 takes care of the communications.
Microsoft will appreciate a big win in China and on the CDMA standard. It has so far signed up a number of licensees for its Windows Mobile OS but received criticism for the number of products actually available.
A Microsoft spokesman earlier this year told silicon.com: "There is no point in just having a huge number of licensees. It is important to us that they are successful."
Nevertheless, the company appears focused on partners such as HTC - the maker of O2's xda - Motorola and Samsung.
Meanwhile competitors are targeting both China and the CDMA platform, which isn't currently found in Western Europe.
Symbian in February inked an agreement with South Korea's LG Electronics, which is the world's fifth-largest handset maker and major CDMA player.
Meanwhile PalmSource, owner of the rival Palm OS increasingly found in smart phones, opened a facility in China at the end of 2002.
And Chinese developers and politicians have themselves expressed a desire to use the open Linux OS as a mobile platform, though this has yet to make much headway.
The Microsoft-China Unicom deal is the fruit of a partnership entered into just over a year ago.