The Enquirer understands the JV has bagged the deal ahead of its main rival BAM.
The bid race started 12 months ago when an OJEU notice was posted for the first phase of infrastructure works covering highways, roads, bridges, river works, utilities and diversions.
The contract is valued at £15m and is expected to last 18 months.
Sources close to the project said: “The word is that the Graham/Hochtief JV have won this with a bid a fair way below their rivals.”
Laing O’Rourke is preferred contractor on the main £700m construction package for joint owners Hammerson and Standard Life Investments.