File picture: Max Rossi / Reuters.

Milan - Formula One is walking a tightrope as new owner Liberty Media plans to grow the sport in America, Ferrari chairman Sergio Marchionne has warned.

Marchionne, who is also chief executive of Fiat Chrysler, recognised that there was a big opportunity to win new audiences in the United States but said the sport's heritage had to be respected.

US-based Liberty, which took over the sport in January, is planning to add at least one North American race to the calendar after 2018 and want to build up the show around grand prix weekends.

"I think it’s fair to say that (F1 chairman) Chase (Carey) and I agree we need space in the United States," Marchionne told reporters at a presentation on Saturday of Alfa Romeo's new partnership with the Swiss Sauber team. Carey also attended the event.

"I think there is an opportunity here, if we do the things right, to make this a relevant sport in the US environment. "And if we do that I think it will benefit the sport tremendously," added Marchionne.

"But I put a big proviso on this.

"We need to be careful that this desire to make us attractive to the American public doesn’t end up sapping away the DNA of a sport that has some noble origins."

Marchionne highlighted the US Grand Prix in Austin that saw big fight boxing announcer Michael Buffer present drivers to the crowd individually before the race and then make his signature call of "Let's get ready to rumble".

Marchionne, who has dual Italian and Canadian citizenship, said the dignity of the sport must be respected.

"I think we need to preserve it, we need to modernise it in a way which Americans find relevant," said Marchionne. "And that’s the tricky part that I think Chase and I need to walk.

"We’re walking a tightrope on this because if we go too far to try and appeal..."

"The performance down in Austin and the way in which we arranged the show was not what I think a Formula One event ought to be. But it was part of a trial and error exercise, I don’t think it worked incredibly well.

"I think a lot of the Europeans were somewhat taken aback by what happened. We need to find a halfway house that somehow appeases and actually enhances the interest of the public on both sides of the pond."

Marchionne said a threat made last month to take Ferrari out of the sport after 2020, if Formula One made changes that were not in the Italian team's interests, was real but there was enough time to sort things out.

Ferrari, the sport's oldest and most successful team, has taken issue with a proposed simpler and cheaper engine for 2021 while cost caps and revenue distribution are other thorny subjects.