Martin Plowman will move to sportscar racing for 2012 having signed for Conquest's new American Le Mans Series LMP2 programme.
The 24-year-old Briton will share Conquest Endurance's Morgan-Judd with sportscar regular David Heinemeier Hansson.
Plowman made three IndyCar appearances with Sam Schmidt Motorsports last year, and caught Conquest team boss Eric Bachelart's eye in the process.
"When we announced the expansion of our operation with the formation of Conquest Endurance in December, I knew we had a lot of work to do to be ready for Sebring," said Eric Bachelart, Conquest Endurance team owner. "Finding drivers was on high on that 'to do' list.
"Martin really impressed me in his three starts in the IZOD IndyCar Series last season, so I am very happy to have him join Conquest.
"David's solid racing resume, combined with his off-track success, tells me he is a focused individual who will complement Martin in the cockpit."