Flynn Restaurant Group, the world’s largest fast food franchise operator, with ambitions to be the largest global franchise operator across all markets, has entered the fitness market with the acquisition of a portfolio of Planet Fitness clubs.

The move is part of a ‘third stage’ of growth for the business, which has a $US2.2 billion portfolio, a $US4.5 billion turnover, 2,600 properties and a 30 per cent annualised growth record. It currently employs 75,000 people.

The company said it is targeting health and fitness and also the beauty market, indicating a possible move into the wellness sector in the future.

Flynn, which owns thousands of Wendy's, Applebee's, Taco Bell, Pizza Hut and Panera Bread locations across the US and Canada, as well as 121 hotels – 109 of which are franchised – has acquired 37 Planet Fitness in Boston and Atlanta from Alder Partners.

It’s the first time the group – which launched in 1999 – has ventured outside the restaurant and hotel sector.

To reflect its diversification, the company has also rebranded itself as Flynn Group.

In the short term, it plans to expand its newly-acquired Planet Fitness portfolio by adding three new clubs, while medium-term, there are plans to become a major force in fitness by building new locations.

Its new Flynn Planet Fitness division will be led by Stanley DeMartinis Jr, with Stella Giangregorio named as vice president of operations.

DeMartinis has driven the operations of the 37 Planet Fitness sites as CEO of Alder Partners, his family business, since 2010 and will now do the same as president of Flynn Planet Fitness.

"This was our first step outside restaurants and hotels and demonstrates the potential for us to grow more broadly across consumer-facing franchise businesses," said CEO and founder of Flynn Group, Greg Flynn, who told San Francisco Business Times the deal was worth “hundreds of millions of dollars”.

“We’re eager to accelerate growth across all channels and to bring our full capabilities to bear to drive even more value for our franchise systems and customers alike,” said Flynn.