Bristol developer Ashfield Land plans to build a retail and cinema complex on the site of a former technical college, which has already been demolished by specialist Wring.
ISG has now signed a contract after fighting off rival bidders Kier, McLaren, Vinci and Wates.
The job includes a 52,000 sq ft Morrison’s store, eight restaurants, a 30,000 sq ft six-screen Cineworld cinema and a 450-space car park.
Upton McGougan is the mechanical and electrical consultant on the project, which is due to complete at the end of 2014.