Scott Sharp is to return to the IndyCar Series to contest the Indianapolis 500 with Panther Racing.
The 41-year-old American left IndyCar for the American Le Mans Series at the end of 2007, and has since driven for the Highcroft Acura team alongside David Brabham. The duo took the new LMP1 Acura's first victory in St Petersburg last weekend.
Speculation had initially linked Sharp to a one-off Indy programme with Highcroft, but he has now finalised a deal to drive for former series champion Panther.
"We've been having conversations about having Scott drive for us for the last four years," Panther owner John Barnes said.
"As a team, we're excited to get this programme finalised early so we can be prepared to make a strong run at the Indianapolis 500 this year.
"We certainly feel like Scott is a very capable and experienced driver, and he and Dan Wheldon will really be a force during the month."
Sharp's car will be sponsored by his regular backer Tequila Patron.
"I can't express how excited I am to be back at the Indianapolis 500, especially with the chance to team with Tequila Patron and Panther Racing," he said.
"John Barnes and the entire Panther team are relentless in pushing their cars to the top and that has shown in their results. We will be a great combination."
Although Panther has yet to take an Indy 500 victory, the team is invariably among the frontrunners in IndyCar's showpiece race, taking second with Vitor Meira last year.
Sharp won nine races during his IndyCar career and shared the inaugural Indy Racing League title with Buzz Calkins in 1996. He also took pole at Indy in 2001, although he crashed out of the race on the opening lap.