Scot Paul Di Resta is returning to compete in the German Touring Car Championship (DTM) for Mercedes this season after failing to nail down a place with a Formula One team.
The 27-year-old won the German title in 2007 and then moved into Formula One to drive for Force India.
He enjoyed some modest success early on in F1, but disappointed last season and his drive went to Mexican Sergio Perez, who had been discarded at McLaren.
"Mercedes-Benz has given me a car I can use to fight for the title," he said. "I realise that it will not be easy," Di Resta said.
The Scot drove in the German series for three seasons from 2007, earning six wins, six pole positions and seven fastest laps in his 42 races before switching to Force India, where he scored 121 points in 58 grands prix.
Di Resta will join up with another British former DTM champion - 2005 winner Gary Paffett - at Mercedes and will be one of seven former title winners to have confirmed their participation in the series.
"It feels really good to be back in the DTM and to see so many familiar faces again," Di Resta said.
"Much has changed since my last DTM race in Shanghai in 2010, with new cars, a new set of rules and a third manufacturer, but what has not changed is my enormous appetite for success.
"My competitors already have two years of experience with the new generation of vehicles but, starting with today's first test, I'll be going flat out in order to be capable of winning at the Hockenheim season opener in early May."