Microsoft announced on Thursday that its Surface Pro, a version of its new tablet aimed at business users, would be available in January starting at $899 for US customers.

The Surface Pro will be powered by an Intel processor and have a full version of the new Windows 8 operating system, which is designed with both PCs and tablets in mind.

"It's a full PC AND a tablet," said a blog post from Microsoft's Panos Panay.

"And all this in a PC that will weigh less than two pounds and be less than 14 millimeters thick. We are excited about both Surface with Windows RT and Surface with Windows 8 Pro."

Microsoft started selling the Surface last month in a version aimed at consumers with a mobile-style processor and a tweaked version of its new operating system called Windows RT. It pricing was roughly in line the the iPad, the top-selling tablet.

The Surface Pro will be more expensive, and is apparently aimed at corporate users and those seeking a laptop replacement. The least expensive version with 64 gigabytes of memory will sell for $899, not including the touch cover with keyboard. A 128 GB version will start at $999.

"Surface with Windows 8 Pro uses the same familiar elegant design principles as Surface with Windows RT," Panay said.

Chief executive Steve Ballmer has described the iPad challenger -- complete with a built-in stand and ultra thin covers which double as keyboards in a range of colors -- as a tablet that "works and plays."