The Clydebank businessman's Bannatyne Group has entered into the deal with M&G Investments, which will allow it to clear its loans from the failed Anglo Irish bank.
Dragons' Den star Mr Bannatyne borrowed £180m from the Bank in 2006 to buy 24 fitness clubs from the Hilton Group and has reportedly been paying back the debt at a rate of £10m a year.
However, the Ango Irish Bank was nationalised by the Irish government in 2009, and liquidator KPMG was called in to recover its debts last year.
This has opened up the way for Bannatyne to pay off the money owed at a lower rate. All the sites will be leased to Bannatyne Fitness Ltd, and the deal involves the sale of land and buildings and the creation of new long-term lease agreements with the new landlord.
The company will retain long-term control of the buildings via very long and secure leasehold interests.
Mr Bannatyne, who also went through a costly divorce from his second wife Joanne McCue in recent years, said: "Our premium business is successful, sustainable and profitable and is an ideal tenant to provide M&G's investors with reliable returns."