Nelson Philippe has joined Conquest Racing for the IndyCar rounds at Sears Point later this month and the October finale at Homestead-Miami.
The 23-year-old Frenchman has previously raced for the team in Champ Cars in 2004-05 and again in 2007, and contested this year's Indianapolis 500 with HVM Racing.
"I'm very happy to be returning to Conquest Racing, it is an excellent team I have very much enjoyed working with in the past and look forward to working with again this season," said Philippe.
"I'm excited to get back behind the wheel of an Indy car again and can't wait to drive it on the road course at Sears Point."
Conquest also hopes to run Philippe for a full IndyCar campaign in 2010.
"By doing only three races this year, I am keeping my rookie status and I can't wait to fight for the Rookie of the Year title in 2010. I'd also like to thank Eric [Bachelart, Conquest team owner] for giving me this opportunity."
Bachelart added: "We've always maintained an excellent relationship with Nelson and we're very happy to have him back with us once again.
"We first had Nelson with us back when he was an 18-year-old rookie and it's been nice to see him mature into the driver he is today. He had his first taste of the Dallara back in May at Indianapolis and we look forward to seeing him back in an Indy car at Sears Point and Homestead-Miami."
Philippe holds the record for the youngest driver to start a Champ Car race, at 17, and is also the youngest winner following his victory at Surfers Paradise in 2006 aged 20.