The 14in X-Slim X400 weighs only 1.5kg with battery included, the 15in X-Slim X600 2.1kg. Both laptops are less than an inch thick, have 16:9 aspect LED screens and Blu-ray Disc support. The 15in X600 has a separate GPU, but don't expect it to be a gaming machine.
All the MSI X-Slim laptops will run Windows Vista and come with 2GB RAM.
"MSI's latest X-Slim Series is a complete line of products designed to set new industry standards and the introduction of the X-Slim Series will further strengthens our position in the notebook market and helps us reach a new development milestone," said MSI CEO Joseph Hsu.
The smaller X320 and the X340 laptops share the same, slim chassis, ranging in thickness from 6.6mm to 19.8mm. For added battery life MSI's X-Slim range offers an optional 8-cell battery for the X340 and X400, and an optional 9-cell battery for the larger X600.
The X320 has a 250GB hard disk drive, an Intel Atom processor running at 1.6GHz. The X340 has a 320GB hard drive and an Intel Centrino CULV SU3500 1.4GHz processor, as well as an HDMI port.
The MSI X-Slim X320 will start at £659, the X340 £859. An optional extra is the £199 external Blu-ray optical drive.