Manchester City Council has awarded Bruntwood a £10m refurbishment and ongoing management contract for Heron House, its 123,000 sq ft office in Albert Square.
Work is due to start on the building later this year, leading to a potential subletting of the property.
Heron House is a six-storey office, retail and leisure block which is let to Manchester City Council for in excess of 21 years. The council also owns the freehold, while a 125-year leasehold is owned by a private investor.
There are 14,000 sq ft of leisure and retail space on the ground floor, and the upper five floors are made up of 109,600 sq ft of offices.
Sub-tenants include Trowers & Hamlins Solicitors, Leech & Co Solicitors, Workman, Greggs, Wings Restaurant and Slug & Lettuce bar and restaurant.