Cheshire West & Chester Council selected the firm ahead of Vinci, Bowmer & Kirkland and a Farrans/Gilbert Ash JV.
Balfour Beatty will now start on site in September, with enabling works to deliver 300,000 sq ft of retail and leisure units starting immediately.
The Cheshire town will be transformed by the riverside mixed-use scheme ending decades of delay caused by salt mining subsidence.
Planning is in place for an Odeon cinema, major Asda store, hotel, restaurants, bars, shops, petrol station and additional free car parking.
An impact study commissioned by Cheshire West and Chester predicts the 8.26 hectare Barons Quay development will reverse a trend of people shopping elsewhere.
Architect Broadway Malyan drew up the masterplan for the 8-acre site bounded by Weaver Navigation, Witton Street and Matalan and Sainsbury’s stores.
Northwich has been at the centre of Britain’s salt industry since Roman times but the legacy of unstable mines beneath the town centre prevented any significant growth in the past 30 years.
A £32m programme completed in 2007 stabilised the abandoned mines by replacing millions of litres of brine from the mines with a mixture of pulverised fuel ash and cement and clearing the way for development.
The project team advising CWAC includes building consultant Rider Levett Bucknall, architect Broadway Malyan, agent Lambert Smith Hampton and Tushingham Moore, project manager Fraser Blair Associates and engineer Curtins Consulting.