Sebastien Bourdais will contest the final three rounds of the Superleague Formula for Spanish club FC Sevilla, starting at Estoril this weekend.
The 30-year-old Frenchman, who was released by Scuderia Toro Rosso after this year's German Grand Prix, sampled the 750hp Superleague car in testing at Magny-Cours last week ahead of his debut in Portugal.
"For a driver, Superleague is the best alternative to F1. Today, it's the only other championship in Europe to offer a driver the possibility of racing single-seaters at a high, professional level," said Bourdais.
"My desire is evidently to be competitive straight away at Estoril. I only did a few laps in the car and the team is quite new to the championship, so to win as soon as my first race will not be easy for sure. I also want to have fun, which hasn't often been the case for me during this last year."
The Frenchman, who finished second at Le Mans this year for Peugeot, says Superleague's qualifying and race format will make driving in the series feel more like Champ Car, in which he won four consecutive titles, than F1.
"I will discover a qualifying system which is different to what I've been used to as it requires a very tactical approach," he said. "As far as the three races go, the totally reversed grid for the second reminds me of Formula Campus.
"This creates a lot of overtaking opportunities which improves the overall show on track, especially if the objective is to secure a place in the super final. To some degree though, Superleague Formula reminds me of racing in Champ Car."
Bourdais will be the fourth ex-F1 driver racing in Superleague at Estoril, along with Giorgio Pantano, Antonio Pizzonia and Enrique Bernoldi.
Superleague president Alex Andreu added: "Superleague Formula is very happy and very proud to welcome a driver with as many titles as Sebastien Bourdais. Our objective is to attract the best professional drivers to our series. Giorgio Pantano, Antonio Pizzonia and today Sebastien Bourdais are among these.
"We're also hopeful that others will join us shortly. The more drivers we have of their caliber, the more Superleague will carve its rightful place in the modern motorsport landscape, as well as offering a quality show to its fans."