The historic building on Castle Street will be sold by Allsop auctioneers on November 9.
Potential buyers need to register with the company ahead of the sale.
An Allsop spokesman said a legal pack would go live on the website in the next day so people had time to do ‘due diligence’ checks.
The building will be ‘sold as seen’ and once the hammer comes down contracts are deemed to have been exchanged and a legal agreement is in place, he added.
“It’s a very interesting asset and we’re sure it will create a certain buzz,” the spokesman said.
The Grade-II listed building was put on the market in June after lenders pulled the plug on developer Efe Omu.
Insolvency firm Wilson Field was appointed to sell it. There were more than five offers, but delays led to the firm deciding to auction it off.
A spokeswoman said: “The sale of the former courthouse presents a fantastic opportunity for someone to restore this historic landmark building.
“In 2019, full planning permission was granted for redevelopment of the building into 12 ‘Pod’ hotel rooms, 12 serviced apartments and a ‘souk’ style market to the lower ground floor.
“The building may be suitable for other uses subject to obtaining the relevant permissions.”
Following the auction, a buyer has 20 days to complete.
The Old Town Hall on Castle Street dates back to 1808. It has been disused since 1996 and is badly dilapidated.
Mr Omu also lost another one of his projects, the former Cannon Hotel, opposite the Old Town Hall on Castle Street. It was also put up for sale.