The section will be headed by former construction managing director Alistair Wivell, who will report to main board director Malcolm Eckersall.
The firm's regional construction interests will now be in a separate building division, which will be headed by Ken Winter. Winter was formerly managing director of the group's northern construction division. He will report to main board director Paul Lester.
Andy Rose, former head of major projects, has joined the rail division as chief operating officer, a newly created role. He will oversee the UK and international rail operations.