Italian contractors Impregilo has been provisionally awarded by Milan City Council to select a public private partnership to construct Line 4 on the metro system costing €2.7bn (£2.4bn).
The new line, which will be driverless and fully automated, will cover a 15.2km stretch from Linate to Lorenteggio.
The project covers detailed and executive design and construction of two single-track tunnels, one in each direction, with 21 stations and a depot/workshop.
The overall value of the investment, consisting largely of civil works, supply of technological services and mechanical equipment, is approximately £1.5bn, of which about 2/3 will be financed by funding provided by the Italian State and Milan City Council.
Impregilo and Astaldi will be responsible, on an equal basis, for the civil works, totalling approximately £775M overall.
The concession is for 30 years, including 6.5 years for engineering and construction works, and the remaining 23.5 years for the operating phase.