The Bannatynes chain of gyms is shaping up for a sale that could net up to £100 million for its founder, it was reported today. Duncan Bannatyne, who set up the company in 1996, is understood to have held talks with two financial advisers about finding a buyer for the 32 clubs.No plan has been agreed for the business which is believed to be worth up to £180 million, including £80 million of debt. Bannatynes owns most of its own freehold estate, which would appeal to bidders interested in property as well as fitness companies.