Atlantia, the Italian infrastructure group controlled by the Benetton family, has agreed to sell its toll road arm for €9.3bn, bringing to an end a three-year dispute with the Italian government.

The group of investors that bought Autostrade per l’Italia (Aspi) was led by state-controlled Cassa Depositi e Prestiti (CDP) and included Blackstone of the US and Australia’s Macquarie.

Atlantia said its board had accepted a binding offer in a statement on Thursday, with its 88 per cent stake bought through a new investment vehicle owned by the groups.

CDP will own 51 per cent of the new vehicle and the two funds will each own a 24.5 per cent stake. The signing of the share purchase agreement is scheduled for Friday.

It brings down the curtain on a row that pitted Rome against Atlantia’s shareholders, including the Benetton family and UK-based hedge fund TCI, following the collapse of a Genoa bridge that killed 43 people in 2018.

Last summer Atlantia had agreed to relinquish control of its toll road business to Italy’s CDP, but major disagreements over the asset’s valuation and the terms of the concession to operate the infrastructure derailed the plan several times.

In July, TCI’s founder, Chris Hohn, lodged a complaint with the European Commission claiming the Italian government was trying to illegally force Atlantia to renounce its toll roads unit.

Atlantia had been at loggerheads with the government over its lucrative concession to operate the majority of the country’s toll roads since the bridge disaster.

Several former Atlantia and Aspi executives are under investigation for the fatal collapse. According to prosecutors in Genoa, the bridge crumbled to the ground because of scarce maintenance by its operator.

Three years ago, Italy’s senior coalition partner, the Five Star Movement, vowed to revoke Atlantia’s concession to operate the toll roads as a way to punish the group and its shareholders.

The option was never pursued as it would have cost the Italian state billions in compensation under the terms of the agreement signed in 2008.

The decision to sell the asset to CDP, Blackstone and Macquarie was approved by the majority of Atlantia’s shareholders, including TCI, last month.

Proxy advisers such as the Institutional Shareholder Services and Glass Lewis had also backed the sale. Meanwhile, Spain’s ACS’ more lucrative offer, first reported by the Financial Times in April, failed to materialise.

According to people involved in the negotiations, investors decided to back the sale after the terms of the concession to operate the toll roads had been amended by the Italian government.

The business will be less lucrative for shareholders going forward, according to Italian officials. This meant the asset’s valuation had inevitably dropped.

CDP, Blackstone and Macquarie declined to comment.

The deal is expected to be finalised by the end of the year, according to Atlantia.