Palace Capital has agreed to pay £20.7m for the company that currently owns Sol Central, subject to shareholders' approval.
Chief executive Neil Sinclair said they were looking to invest in a town like Northampton.
Built on Marefair 13 years ago, Sol Central is currently home to a cinema, a hotel, gyms, and a car park.
But, Mr Sinclair said the leisure complex lacked restaurants and that would be the key to its success in the future.
He said: "There's no restaurants in there at all and that's what's cost the centre to not get anywhere and we need to improve it, and get people going in there.
"The cinema is getting a reasonable number through the door but they would get far more people if they could, say go for a pizza."
Currently there are two vacant premises on site and Palace Capital aims to get those re-let.
He said there were many changes under way in Northampton; new buildings and businesses would provide many more opportunities to get people in to Sol Central.
"It's an exciting time for Northampton, but you have to take your hat off to the town council and to the county council for attracting people like us... who are willing to say we will come in and will take it over," he said.