Williams have thrown Indian driver Narain Karthikeyan [Images] a Formula One lifeline by appointing him as their second test driver for 2006.

Karthikeyan, dubbed the 'Fastest Indian on Wheels', raced for Jordan last year but lost his seat when the team was renamed Midland.

The 29-year-old Chennai driver tested twice for Williams last month and had hoped to land the main test and reserve role. Williams signed experienced Austrian Alex Wurz from McLaren instead.

"Narain's brief period in the car in December, during which he provided valuable feedback, made a very distinct impression on our engineers," said team boss Frank Williams in a statement before the launch of the new Williams FW28 car on Friday.

"Having a year's Grand Prix racing and testing to his credit is also advantageous for us so I am pleased we can now formally confirm his appointment."

Karthikeyan, the only Indian to race and score points in Formula One, said it had taken him some time to resolve his position for 2006.

"Joining the team was the best option for me," he said. "I am looking forward to testing the FW28 and making a contribution to Williams' competitiveness this season."

Former champions Williams finished fifth last year in the constructors' championship and are using Cosworth engines after parting with BMW [Images].

Australian Mark Webber [Images] and German newcomer Nico Rosberg, son of Finland's 1982 world champion Keke Rosberg, are their race drivers.

• Formula One coverage