Deputy prime minister Luigi Di Maio on Wednesday charged that the tragedy "could have been avoided" and that it was clear that Autostrade per l'Italia was at fault for not carrying out maintenance.
The Italian government said it intended to fine the firm 150 million euros and cancel its concession. It was unclear if the entire concession or just management of the A10 motorway was at stake.
Atlantia said on its website that it has spent 11.4 billion euros to improve 923 km of Italian motorways, and was waiting for approval from authorities to build a bypass around Genoa.
Atlantia's history is intertwined with Autostrade per l'Italia, which was privatised in 1999 and acquired by investors including the Benetton group. In 2003 the motorway and other infrastructure assets were separated and the holding company, which eventually took the name Atlantia, was listed on the Milan stock exchange.
Atlantia owns 88 percent of Autostrade per l'Italia, which accounted for just under two-thirds of its 5.97 billion euros in revenue last year. Atlantia earned a net profit of nearly 1.2 billion euros for the year.
Overall it operates more than 5,000 km of motorways in Brazil, Chile, India and Poland.
It also operates the Mount Blanc tunnel and recently became the top shareholder in Getlink, which operates Channel Tunnel, buying a 15.5 percent stake that controls over a quarter of voting rights for nearly 1.1 billion euros.
Atlantia stands to soon gain more motorways.
It recently teamed up with the German-Spanish group Hochtief-ACS to buy for 18.2 billion euros the Spanish firm Abertis, which calls itself the world's top motorway operator with 8,600 kilometres of toll roads in 15 countries.
Atlantia will own 50 percent plus one share of the joint venture that will own Abertis.
The Italian group entered the airport management business in 2013 with contracts for Rome's two airports, Fiumicino and Ciampino.
In 2016, Atlantia together with French electricity firm EDF bought 60 percent stakes held by the French state in the airports in the Nice, Cannes and Saint-Tropez airports.
Atlantia's share price fell by more than 10 percent at one point during trading on Tuesday, closing the day down 5.4 percent at 23.54 euros.
The Milan stock exchange was closed for a holiday on Wednesday.
