Refurbishment work will involve creating large open-plan office spaces and doubling the number of staff able to work in the building.
Bolton council will now work with ISG to produce a full design and costing for the project by the end of the year, with work set to start on site in early 2013.
The council and ISG will also work with conservation experts to ensure that proposed plans are in keeping with the historical significance of the listed building.
Up to 70% of the materials, and workforce required to deliver the project will be procured locally, either directly or via subcontractors.
Councillor Cliff Morris, Leader of Bolton Council said: “We are delighted to have appointed ISG to design, cost and refurbish Bolton Town Hall, as they have a long and successful track record of redeveloping heritage buildings.”
ISG’s Jim Parker, managing director – North West, added: “Bolton Town Hall is an iconic regional landmark and we will be working closely with the Council to both preserve and redevelop this historically important building to better serve the local community and enhance the working environment for staff.
“Bolton Council’s core focus on eliminating waste and driving efficiencies throughout the project has led to our early involvement in the scheme.
“This enlightened approach will undoubtedly prove beneficial as we are able to thoroughly explore options and make informed recommendations to maximise time and cost savings for the Town Hall redevelopment.”