(REUTERS) - The Italian Grand Prix will stay on the Formula One calendar at Monza for at least three more years but a deal has yet to be signed, the sport's commercial supremo Bernie Ecclestone said on Friday.

"The contract is here for three years but I hope we're here for another 100 years," he told reporters at the historic circuit near Milan, whose current deal expires after Sunday's race.

"Regretfully, legally we can't sign it here. But more important is that we have an agreement thanks to our lawyers and we are getting all the small details sorted," added the 85-year-old Briton.

Ecclestone was speaking after a news conference attended by International Automobile Federation (FIA) president Jean Todt and Italian Federation (ACI) head Angelo Sticchi Damiani that had been expected to announce the end of a long-running saga.

Sticchi Damiani had told Reuters in the morning that he would be signing the deal later, but that plan clearly changed after he met Ecclestone.

Ecclestone shrugged off the delay.

"When two lawyers get together, and one's Italian and one's English... but basically everything's alright," he said.

"We are going to sign it in London. We can't sign here. Everyone should be happy, we're going to keep the race in Monza."

Asked why the deal would be for just three years, rather than the longer-term contracts agreed with some other circuits, Ecclestone indicated that was down to the Italian organisers.

"You have to do an arrangement that suits both parties. The world is changing so quick today, who knows what is going to happen in a few years," he added.

Monza has hosted a race every year bar one since the Formula One championship started in 1950 and is regarded as the temple of Italian motorsport, and spiritual home of glamour team Ferrari.

The circuit is the fastest on the calendar, with a fearsome reputation as the scene of fatal accidents in the past, and one of the most atmospheric. Its absence would have been unthinkable for most fans.