Williams 2018 Formula 1 seat contender Paul di Resta will make his sportscar racing debut with United Autosports in next year's Rolex 24 at Daytona.
United has brought in di Resta to race one of its Ligier JS P217s alongside Will Owen in the 2018 IMSA WeatherTech SportsCar Championship curtain-raiser.
The Zak Brown-owned team's Daytona line-up will also include European Formula 3 champion and McLaren F1 junior Lando Norris in the sister car alongside Phillip Hanson.
"I'm really looking forward to racing at Daytona and with United Autosports," said di Resta. "I've never done a 24-hour race and never raced a prototype so it's all new to me, but I'm looking forward to the challenge
"Entering a 24-hour race is something I've looked at doing before and when Zak asked, I jumped at the opportunity.
"I plan to do some testing ahead of the race to get integrated into the team and to get a shot at driving the car prior to heading to Daytona in January."
Di Resta ended a three-year absence from the F1 grid in August when he was called in by Williams to replace the unwell Felipe Massa for the Hungarian Grand Prix.
He is now vying with Massa and Robert Kubica for a full-time 2018 race seat, and took part in an evaluation test in a '14 Williams F1 car at the Hungaroring this week.
Since his previous F1 deal with Force India ended, di Resta has spent recent seasons racing for Mercedes in the DTM.
"Although he's not driven our car before, he's had plenty of racing experience in different categories so I'm confident he will have a good race," said Brown.