The deal with Petty and sponsor Window World, which fielded John Andretti's car in last year's race, starts with his May 1 debut at Kansas Speedway in the Izod IndyCar Series race.
Andretti will then attempt to secure his 11th Indianapolis 500 start, behind the wheel of the No. 43 Team Window World car. If he succeeds and drives for a team owned by his cousin in the May 30 race, it will add to the Andretti family's Indianapolis Motor Speedway legacy.
John Andretti has made 10 Indy 500 starts, with a best finish of fifth in 1991.