Atlantia, in which the Benetton family has a 30% stake, agreed in July to pull out of Autostrade per l'Italia following a 2018 bridge collapse, in which 43 people died.

But sources said the two parties had failed so far to hammer out the details of a deal that meets the conditions set by Rome and wins the support of minority investors in both Atlantia and Autostrade.

Atlantia, which owns 88% in Autostrade and is expected to hold a board meeting on Thursday to discuss the deal, declined to comment.

According to people close to the matter, Italy wants Atlantia to sign a formal commitment to sell Autostrade to CDP as a pre-condition for the government stopping a procedure it had initiated to revoke Autostrade's concession following the bridge disaster.

Rome believes Atlantia has already accepted passing control of Autostrade to the state lender as part of the July agreement, the government source added.

The motorway group, however, considers that request unlawful and sent a letter to the European Commission this month asking it to intervene, the people added.

A source close to Atlantia said on Wednesday that forcing the group to sell the unit to the CDP would violate market rules.

Another issue which has stood in the way of a final deal with CDP is the question of who would handle potential future legal claims against the motorway network.

Atlantia is unwilling to offer any legal safeguards to CDP for possible damages or disruptions that might occur on the network after CDP takes over, something that the state lender says is unacceptable, sources said.

The government is also unwilling to agree to Atlantia's request for CDP to take over part its debt, fearing it could be criticised for granting generous terms to the Benettons.

By Giuseppe Fonte