The battle to produce the world's lightest laptop continues, with Toshiba launching a new ultraportable weighing just 1.08kg.

The Toshiba Portégé R500-S5007V is lighter than both Apple's MacBook Air, which weighs 1.36kg, and Lenovo's Thinkpad X300, which weighs around 1.33kg. The laptop measures 0.77in at its thinnest point, according to Toshiba.

Lenovo ThinkPad X300 review

Apple MacBook Air review

The company also claimed that the new laptop was the first to include a 128GB solid-state drive (SSD) to replace the hard drive. Laptops to date have had 64GB of storage, though both Lenovo and Apple provide 128GB of storage through two 64GB modules. The new laptop will only be available with one 128GB SSD for now, a Toshiba spokesperson said.

Unlike a traditional hard drive, an SSD has no moving parts so consumes less power. The laptop, which runs on a lithium-ion battery, lasts for eight hours on a single charge, according to Toshiba.

Battery life is also preserved by the laptop's transreflective 12.1in screen, which can shut down the LED (light-emitting diode) backlighting by reflecting the sun's rays to illuminate the screen, according to Toshiba.

For $2,999 (£1,500), US users can get a laptop powered by an Intel Core 2 Duo U7700 processor at 1.33GHz, with 2MB of cache and 2GB of RAM. There are no details of the UK price as yet.

It will come with Windows Vista Business OS, which is also downgradable to Windows XP Professional.

The laptop includes a SuperMulti optical drive that can read and rewrite DVD and CD media, wired and wireless 802.11 a/g/n networking, Bluetooth 2.0 support and built-in safety features to protect laptop data during falls.

The Portégé R500-S5007V is a standard configuration, however, Toshiba offers similar configurations with a hard-drive option, a company spokesperson said.

Toshiba said the laptop includes a specially built motherboard that can provide the same functionality of boards found in 15.4in laptops, but is one-third the size.

The laptop will start shipping in the third quarter this year, according to the company. The company didn't comment on worldwide availability.

See Laptop Advisor for more laptop news, reviews and tutorials