The group overseeing the ambitious development today formally advertised two deals in a surprise move that could see seperate contractors handle the project's delivery.
The combined value of the contracts is expected to fall between £375 million and £550 million.
Crossrail will hire a project delivery partner, responsible for delivering the central tunnel section of the rail link under the West End and City, in a deal worth between £300 million and £400 million.
The second contract, tipped to be worth £75 million to £150 million, is for a programme delivery partner to work with Crossrail overseeing the entire development.
US consultant is an early favourite for the larger deal after working with Crossrail in the role of development manager for more than two years.
But Parsons Brinckerhoff, Balfour Beatty, Arup and C2MHill are all poised to bid for the work. The deadline for tenders is 16 May.