Lenovo has announced a new range of ThinkPad ultraportables with longer battery life and improved wireless performance over previous models.

Available from June, the new ThinkPad X61, X61s and X61 Tablet PC all weigh less than 2kg, feature 12.1in displays and are powered by Intel Core 2 Duo processors. New security features include a hard drive password and the ability to disable any port on the outside of the system.

“As the traditional work place environment continues to change, customers are telling us portability, reliability, connectivity and security are most important to them,” said Marc Godin, vice president of Lenovo's worldwide laptop business unit.

With the ThinkPad X61 and X61s, an improved Ultra Connect II wireless design offers increased range over previous models as well as 30 percent greater throughput, Lenovo said. However, the new models have a claimed battery life of up to 12 hours when using an optional eight-cell battery.

The 1.4kg ThinkPad X61 has Core 2 Duo processors at 2GHz or 1.8GHz, while the lighter (1.32kg) ThinkPad X61s runs low voltage processors at 1.6GHz or 1.4GHz.

Lenovo's new Tablet version can be fitted with an optional SuperView display that is less reflective than other display panels for easier reading, even in direct sunlight, the company said.

The X61 Tablet itself is based on 1.6GHz or 1.4GHz processors and weighs 1.7kg with its standard 4 cell battery pack. All models take up to 4GB of memory and can be pre-loaded with Vista or XP.

US prices for the ThinkPad X61, X61s and X61 Tablet PC start at $1,484 (£750), $1,474 (£745) and $1,779 (£898), respectively. Exact UK pricing has yet to be disclosed.