Tolent will begin construction on completion of the final site enabling works, which started in January.
The contract includes the construction of 70% of the entire Milburngate development, which makes up phase one of the project on the six-acre riverside site.
The contract award follows the project securing a £120m forward-funding commitment from LaSalle Investment Management, which is enabling the delivery of the first phase.
Phase One includes a cinema, restaurants and a 92-bed Premier Inn hotel.
Tolent will also build 5,000 square metres of speculative offices, creating capacity for more than 400 new jobs, as well as 153 built-to-rent apartments.
Tolent is also on site at two other major developments in the northeast: Hadrian’s Tower, set to be Newcastle’s tallest building; and the Vaux development in Sunderland.
Milburngate is being delivered in joint venture by Durham-based Arlington Real Estate and the Richardson family.
Project director Ian Beaumont said: “Tolent shares our enthusiasm for Durham City and our commitment to delivering a regionally-significant development. We undertook a very detailed and comprehensive selection process to ensure we have a contractor that is able to transform this unique riverside location into the vision we have for Milburngate. We are very pleased to have chosen Tolent and look forward to working closely with them as they begin construction in the next few weeks.”
Tolent chief executive Andy McLeod said: “This project is one of the most significant wins in the history of our business, and is testament to the skills, expertise and growth of our team not only in the region, but across the UK.
“It’s always a privilege to be involved in such transformational projects, and the vision for Milburngate is one we’re committed to delivering for our client, and for the community within Durham City.”