A consortium co-led by Costain, the firm charged with revitalising London Bridge station, has formally secured a £1.8bn HS2 contract to build tunnels and bridges linking Euston station with Old Oak Common.
Today's announcement follows initial awards made by the government made on 17 July.
Costain is a 34 per cent in the SCS consortium, which will deliver the contracts. Its two partners are Swedish firm Skanska (also owning 34 per cent) and Vienna-headquartered Strabag (32 per cent).
Andrew Wyllie, Costain's chief executive, said: "We are delighted to have been awarded these major contracts by HS2 and which follow on from the South Enabling Works Contract awarded last year.
"The awards are further testimony to Costain's collaborative approach and strong track record in applying technology-based innovative solutions in the delivery of large-scale projects."
A new station is to be built at London's Old Oak Common as part of the HS2 expansion. The station is to be a key interchange, with its six platforms welcoming trains to heading north to Liverpool, Glasgow and Edinburgh; and a connection to Crossrail and Heathrow.