ROME- Italy's government has told infrastructure group Atlantia what it must do to retain its toll-road licence, the prime minister said on Tuesday, as government officials said these included a reduced stake in its motorway unit.

Rome has been threatening to revoke the business licence of Atlantia's motorway unit Autostrade per l'Italia following the deadly collapse in 2018 of a bridge in Genoa that was run by the motorway operator.

"There is a revocation procedure in place," Prime Minister Giuseppe Conte told a news conference, adding the government considered "unacceptable" a settlement proposal tabled by Atlantia in March that included 2.9 billion euro ($3.3 billion) compensation for the disaster.

Sources told Reuters the government had set a series of tough conditions Atlantia had to meet to hang on to its licence.

These include Atlantia cutting its 88% stake in Autostrade to below 50% as a way of reducing the influence of the Benetton family which currently owns 30% of the infrastructure group.

The government came up with a plan by which infrastructure fund F2i and state lender CDP would split between them a majority stake in Autostrade, one of the sources said.

The ruling parties have also asked Atlantia to accept tougher rules on motorway tariffs and pay 3.4-billion-euro compensation for the Genoa disaster.

Late last year Rome introduced legislation to drastically cut the amount of compensation it would have to pay Autostrade for revoking its motorway concession in the wake of alleged company shortcomings.

The legislation was pushed through by the anti-establishment 5-Star Movement, the main coalition party which from the start has led the campaign to strip Atlantia of its licence.

In June, Atlantia asked the European Commission to intervene in the dispute, claiming the new measures had unilaterally modified the concession contract, undermining Autostrade's value and damaging investors.

 ($1 = 0.8856 euros)

(Reporting by Angelo Amante and Giuseppe Fonte, editing by Gavin Jones, William Maclean) ((Angelo.Amante@thomsonreuters.com;))