Speed to make IndyCar debut

The American will be eligible for the $5 million bonus available to any non-series-regular who can win the latter event.

The deal marks Speed's return to single-seater racing for the first time since parting company with Toro Rosso mid-way through the 2007 F1 season. He has since raced stock cars, though he dropped out of the NASCAR Sprint Cup when he lost his Red Bull seat at the end of 2010.

"Having the ability to compete in the Indy 500 is a dream for any racing driver, and I am proud to be partnered with Jay Penske in our attempt to drink the milk and win the biggest race in the world," said Speed.

Team boss Jay Penske added: "I am thrilled that Scott chose Dragon Racing and this year's Indy 500 to make his IndyCar debut. As one of America's finest open-wheel racers, Scott's past experience in Formula 1 and NASCAR make him a serious contender at this year's Indy 500 and at the IndyCar Challenge in Las Vegas."

Dragon's main focus this season is on a partial programme with Paul Tracy, but the Canadian has an Indy 500 deal with Dreyer & Reinbold which he secured before the Dragon drive was in place. The team will also run Ho-Pin Tung at Indianapolis in partnership with Sam Schmidt Motorsports.