The works cover the Crossrail West Inner Track Improvements and the Crossrail Old Oak Common and Paddington Approaches and Intercity Express Programme.

The contracts will enable the new Crossrail service to be integrated into Network Rail’s existing infrastructure from Stockley Junction in the West through to Old Oak Common on the approaches to Paddington.

Works involve a wide range of services including design, track work, switches and crossings, overhead line and cable management, together with minor civil engineering works.

Carillion Chief Executive, Richard Howson, said: ”As one of Network Rail’s largest suppliers, we are delighted to have been selected for these important contracts.

“We look forward to continuing our strong relationship with Network Rail through working together to delivering the upgrades required to enable Crossrail to connect to the existing network between Stockley Junction and Old Oak Common.”

The contracts, which are being procured and managed by Network Rail with some funding coming from Crossrail, are due from completion by Summer 2017.

The award came as Carillion issued an upbeat trading statement to the City confirming that rescaling of its UK construction business is now “largely complete”.

Carillion picked-up £900m of construction work during the first half of the year.

Wins included a £400m contract for Battersea Power Station Development Company, a £73m deal for Argent to deliver a further phase of its Kings Cross redevelopment and contracts for Ask worth £50m.

Carillion’s selection as the preferred bidder for the Royal Liverpool Hospital PPP project also includes £335m of construction work.

The company said: “Despite market conditions remaining challenging, new order intake has remained strong and we have continued to win good quality work, in line with our selective approach, to maintain a strong order book and good revenue visibility.  In addition, our pipeline of contract opportunities has increased.

“Therefore, our expectations for the full year and our medium-term targets for growth, remain unchanged.”