Karthikeyan, who was signed up by the then Jordan team, is now a test driver with Williams.

"I'm very proud to drive for my country in A1GP," he said in a team statement. "(Team boss) Frank Williams has kindly agreed for me to race, but my Formula 1 testing duties for Williams will always be my number one priority."

Team India officials turned to Karthikeyan after failing to score a point in the first five races of the 12-race calendar.

The driver had spurned previous offers from A1, saying he wanted to regain a regular drive with an established F1 team.

However, he has not been successful in his bid and said he took up the offer to get a chance to race again.

"In recent months, I have had several offers to drive in America and Japan, but I chose A1GP because the race schedule does not clash with my Formula 1 commitments.

"I hope that I can help A1 Team India improve its performance in the series, as well as heighten its profile back home."

Unlike Formula One, drivers race for national teams in A1GP. The 12-race calendar runs from October to April during the break in the F1 season.