Under the deal, the contractor will deliver electrification to 50km of railway, as part of a wider £80m investment in the line between Cumbernauld and Scotland’s largest city.

As well as the main works, Carillion will also be lengthening the Cumbernauld station platforms and constructing a turnback facility at Springburn.

The project marks the first phase of electrification on the Edinburgh-Glasgow Improvement Programme to be delivered in time for the Commonwealth Games in 2014.

David Simpson, Network Rail route managing director for Scotland, said: “This project further underlines Scotland’s continued commitment to electrifying our rail network.

“This project will create jobs and modernise rail services to Cumbernauld as well as mark the beginning of a transformation of services across the central belt as we begin to deliver the wider EGIP project, enhancing rail travel between the country’s two biggest cities.

“These works will also be an opportunity to continue to develop our new alliancing approach to infrastructure projects – working more closely with contractors, train operators and other stakeholders to deliver in the most efficient and cost-effective way possible for passengers.”

The project will cut around 10 minutes from journey times between Scotland’s two major cities.

It will also transform Glasgow’s Queen Street station into a world-class integrated transport hub and deliver the Edinburgh Gateway Station, connecting services to the tram network and Edinburgh Airport.