Oldham Council has appointed BDP to explore options for reviving the Old Town Hall, which the local authority largely vacated in 1978.
Working with the council, BDP will consider modern uses for the Grade 2-listed building, conserving as much of its historic fabric as possible.
BDP will progress the plans to a stage where planning and listed building consent applications can be submitted, which is expected to be some time this year.
Cllr Jim McMahon, leader of Oldham Council, said: "The Old Town Hall is one of our best known buildings and although it has been left unused for many years we are committed to looking at every option with regard to it. We've always said there will be no quick fix and because of the building's current condition no developer would be prepared to work with us because it is not a viable proposition.
"By bringing BDP on board we will produce a workable scheme that would enable either the council or a developer to take on the building wholesale – or enter into a joint venture with us – safe in the knowledge of what they were taking on.
"Once this work is complete there will be no more obstacles in the way and this will pave the way for proposals which could see the site turned into a cinema or other leisure-based facility."
The Old Town Hall was built in three phases between 1850 and 1917. Essential work to stop further decay and weather damage has already been carried out.
Alan Davies, architect director at BDP, said: "Oldham's Old Town Hall represents an important part of the town's heritage, but because of its layout and historical features it is a difficult building to adapt. For many years it has defied efforts to bring it back into use and it has fallen into disrepair.
"We look forward to sharing our insight and knowledge, and aim to see the conservation and re-use of this historical landmark."
Oldham Council officers moved out of the town hall for the Civic Centre in 1978, although small rooms were used by a variety of groups, and the court room was used as a satellite Crown Court until 1995.