Vale Park Demolition will clear the former RSPCA building, Roscoe Mill and the former Oldham Hide, Skin and Fat property in preparation for what will be the most ambitious redevelopment of the town centre since the 1980s.
Council bosses want to regenerate the area around the new Metrolink station as part of wider plans for the town centre.
The centerpiece of the 150,000 sq ft glazed building complex with undulating roof will be a Marks & Spencer store, plus underground car parking spaces.
The eastern gateway site masterplan also allows for 800 homes in a new neighbourhood with associated retail and leisure uses.
These include a separate discount food store with apartments above, improved public realm, walking and cycling links, plus a modern use for the refurbished and extended Grade II–listed Old Bank building.
WYG Engineering is the structural consultant for the job, which has been designed by Wakefield-based Harris Partnership.