Motorola will sell a new phone that will run on Microsoft's Window's Mobile 6.5 software, the phone maker announced Thursday.

At an event to unveil the ES400 Enterprise Digital Assistant (EDA) device, Motorola said the phone will go on sale in September. Microsoft has been lagging behind in the software market for consumer phones as response has been overwhelming for devices running the Android and Apple iPhone operating systems. Microsoft said it is planning an upgraded version of the Windows Mobile 6.5 software for businesses later this year, which will be branded as Windows Embedded Handheld.

“The new ES400 EDA combines the best features of mobility, communications and task functionality without compromising performance or design – offering mobile workforces the ability to take action and capture information with a single click -- in front of the customer where it counts most,” said Gene Delaney, president, Motorola Enterprise Mobility Solutions, in a statement.

“Motorola has a long history of building phones for the enterprise market using Windows Mobile,” said Avi Greegart, research director, consumer devices, at Current Analysis. The ES400 is a business-oriented device targeted at workers in the field and those doing inventory management, he said, and added that Windows Embedded Handheld is the “bridge” between Windows Mobile 6.5 and Windows Phone 7.

“There are apps that have already been written and deployed for the [Windows Mobile 6.5] operating system and Microsoft appeared to have abandoned that entire mobile enterprise customer base,’’ he said. The software giant is now backtracking and saying it did not mean to do that, he said, by announcing Windows Embedded Handheld.

Greengart said it makes sense for Microsoft to provide a roadmap on how they’re going to transition from Windows Mobile 6.5 to Windows Phone 7, which is more of a consumer-oriented OS. Not all of the features built into Windows Mobile 6.5 are found in Windows Phone 7, he said.

Features of the ES400 include a three-inch color touchscreen display, three keypads, a built-in biometric fingerprint reader, a high-resolution 3.2 MP autofocus digital camera, compatibility with Motorola’s Mobile Security Suite and Mobile Services Platform and the ability to withstand impact and exposure to dust, moisture and rain.