Greg Maffei is stepping down as president and chief executive of Liberty Media, the company that owns Formula 1.

Liberty Media said in a statement Wednesday that Maffei would leave his role when his contract expires at the end of the year and become an advisor. The company’s 83-year-old chairman John Malone will be the interim CEO.

“While it’s never easy to leave an organization as dynamic as Liberty, I am confident that this is the right time,” Maffei, 64, said in a statement.

He was a leading figure in the takeover of F1 in 2017 from long-time rights holder Bernie Ecclestone. At the time, Maffei predicted “an enormous opportunity to grow the sport.”

The years since then have seen a boom in interest in F1, in part driven by the success of the Netflix series “Drive To Survive”. That’s particularly true in the United States, which now hosts three races a year. The Las Vegas Grand Prix is next week.

Liberty Media said in August that it was under investigation by the U.S. Department of Justice over denying Andretti Global’s bid to become F1’s 11th team. Maffei said at the time that the company is open to new entrants applying, and potentially being approved, if certain requirements are met.

Liberty Media also expanded into motorcycle racing in April when it agreed a deal worth around $4.5 billion for the MotoGP series.