IBM will unveil the new ThinkPad X40 next Tuesday as the lightest notebook ever built by the company and the first to incorporate file-recovery technology.

The X40 is currently available in Japan and other countries in Asia, but IBM released information about plans to bring that model to other parts of the world through a promotional mailing of a chocolate ThinkPad, called Tuesday. The company is now releasing specifications for the product, which will be available worldwide as of 24 February, says Grant Shenk, worldwide product manager.

IBM shaved about 410g off the weight of the X31 in order to produce the X40, he said. The new notebook weighs just 2.7Ibs (1.2kg) and measures 26.8x21.1x2.7cm, but comes with a full-size keyboard.

A base configuration costs US $1,499 (£820) with a 1.0GHz ultra-low voltage Pentium M processor from Intel, 256MB of memory, a 20GB hard drive, a 12.1in display, and Intel's Pro/Wireless 2100 802.11b chip. Preconfigured versions of the notebook will be available on Monday, and customers can also build their own systems, Shenk says.

The base configuration comes with a four-cell battery that provides up to 3.5 hours of use under normal circumstances, but an eight-cell battery that lasts for up to 7.5 hours is also available, Shenk adds.

The X40 is IBM's first notebook to come with Rescue and Recovery with Rapid Restore. This feature allows users to access a protected area of the system in the event they are unable to get Microsoft's Windows XP to load properly, he says.

Pressing the Access IBM button during the initial boot process takes a user to a troubleshooting screen where they can determine what is wrong with their system, recover critical files and download them to external media, or access the web through a built-in browser, Shenk explains.

IBM also plans to announce new X31 models with faster Pentium M processors and support for the Rescue and Recovery feature. The X31 was previously the lightest notebook in IBM's product line at 3.6Ibs.