Sergio Marchionne, CEO of Fiat SpA and Chrysler Group LLC, plans to step down at the end of 2018 after completing a five-year turnaround plan for the new Fiat Chrysler Automobiles NV, reported The Detroit News.

Marchionne, 62, told Bloomberg Businessweek that he will “undoubtedly do something else” after the plan, outlined earlier this year, has run its course.

“I am not going to do any more turnarounds,” he told the weekly business magazine. “I’m done; let some of the young punks do it.”

When presenting the new five-year business plan on May 6, Marchionne said he would remain the CEO through at least 2018.

Since taking control of Fiat in 2004, Marchionne is credited with resurrecting the Italian automaker and orchestrating the complete acquisition and turnaround of Chrysler that led to the creation of Fiat Chrysler Automobiles, which is expected to come to fruition Sunday.

FCA was announced by Marchionne in January following Chrysler becoming a wholly-owned subsidiary of Fiat after a $4.35 billion deal with the United Auto Workers union trust fund that pays health care bills for retirees, which owned a minority stake in Chrysler following the auto bailout.

FCA common shares, as previously announced by Marchionne, are also expected to begin trading on the New York Stock Exchange and the Italian stock market on Monday.

Marchionne, known for his off-the-cuff comments, is the longest-serving CEO of any major European or American automaker.

An heir apparent is not obvious for Marchionne, who came to Fiat as an automotive outsider.

In May, Fiat Chairman John Elkann said a succession plan had been discussed, but was “not a topic” at the time.

Elkann, according to Bloomberg Businessweek, has previously mentioned executives who could eventually replace Marchionne: CNH Industrial CEO Richard Tobin; Jeep CEO and President Mike Manley; Alfredo Altavilla, Fiat’s COO for Europe, Africa and Middle East and head of business development; and Cledorvino Belini, head of Fiat in Brazil.