The largest scheme is for the £102m A8 Belfast to Larne Dualling for the Northern Ireland Roads Service.

Costain is working with equal joint venture partners Lagan Construction and Ferrovial Agroman to design and construct the job.

The award follows on from the successful completion of the Early Contractor Involvement consultancy phase of the scheme which started in January 2010.

Construction work will begin immediately and is expected to complete in winter 2015.

Costain has also been appointed as preferred bidder by Severn Trent Water to replace its largest covered service reservoir at Fritchley, near Ambergate, Derbyshire, in a project worth £27m.

The scheme will see the construction of two covered reservoirs of 90 and 50ML capacity, to replace the current 128ML reservoir.

A planning application has been submitted and is currently under consideration by the local planning authority.

Once approved work is due to begin on site in January 2013 for four years, with some early enabling works taking place in coming months.

Andrew Wyllie, Chief Executive of Costain, said: “We are delighted to have been awarded these two contracts.

“They demonstrate, not only the breadth of our service offering, but also our ability to deliver strategically vital infrastructure projects from the initial design stage, through  consultation and project feasibility, to this stage enabling project delivery to commence; as we continue to meet the national needs.”

“Our focus continues in working closely with our partners to deliver excellent outputs for our customers.”