Civil engineering group Costain has won a £107.1m deal to improve a road in Cheshire.Costain said it had secured a contract from the Highways Agency to upgrade the A556 between junction 19 of the M6 at Knutsford and junction 7 of the M56 near Bowdon to create a dual carriageway over a four mile stretch.Work will start immediately, with the new link road expected to open in 2016/7.Chief executive Andrew Wyllie said: "This award is further demonstration of the importance to Costain of long-term, strategic partnerships."Costain shares fell 3p or 1% to 291p in early trading in London.