Microsoft has released details of its new Xbox ahead of next week's E3 computer games fair in Los Angeles.

The company showed off the new console in a half-hour special on MTV last night. The device should be in the shops by Christmas, beating rivals Sony and Nintendo which are not expected to launch next-generation consoles until next year.

"With the first generation of Xbox, our ambition was to change the way people think about video games," said Robbie Bach, chief Xbox officer at Microsoft.

"Starting today with Xbox 360, our ambition is to transform the way people play games and have fun."

The device uses three Power PC processors, a custom ATI graphics processor, and more than 512MB of memory. The graphics systems have been designed for high-definition, wide-screen televisions.

Xbox 360 will also be a central part of Microsoft's Digital Home strategy. A DVD/CD player is built in, and USB 2.0 ports allow music and images to be loaded onto the detachable 20GB hard drive.

Pricing details were not released, but the device is expected to cost roughly double that of the first-generation Xbox.

Microsoft expects to have 30 games available within 90 days of launch, but has not said whether current Xbox games will be compatible.