Imola has filed legal action as it steps up its bid to host the Italian Grand Prix from 2017.

Recent reports claimed that Bernie Ecclestone had inked a deal with the former San Marino GP venue, but the contract could not be signed off because it lacked the endorsement and backing of the Italian automobile club Aci.

To date, the Aci argues that it is empowered to exclusively support historic Monza's quest for a new contract.

However, the Gazzetta di Parma newspaper on Wednesday published a statement by Imola race organisers that confirmed the legal action, saying that it is committed to hosting the next five Italian Grands Prix.

Imola said that in May it signed "a valid contract received by the London office of the boss of Formula 1, Bernard Charles Ecclestone".

"Moreover, the same proposal... to the Autodromo di Monza was not accepted," the statement reportedly added.

Imola's appeal to the Lazio tribunal has been filed against the Aci's refusal to cooperate in terms of backing and the release of funds.

When asked about Monza's efforts to keep the grand prix, Italian olympic chief Giovanni Malago said on Wednesday: "I understand that soon there will be an offer.

"In any case, the Aci, which is heading the negotiations, absolutely wants Monza. I do not know if there are other feasible proposals," he is quoted as saying by La Gazzetta dello Sport.

"I hope that in the days to come there is positive and conclusive news," Malago added.

This year's Italian Grand Prix is scheduled for September 4.