Cannons, the chain of health and fitness clubs, has been sold to one of Britain’s largest private healthcare operators for an estimated £170million.

Nuffield Hospitals, a charitable organisation that runs hospitals, diagnostic services and employee health schemes, bought Health Club Investment Group, the parent company of Cannons, from Royal Bank of Scotland (RBS) and PPM Capital.

David Mobbs, its chief executive, said that the deal was in line with the strategy of diversifying into a “broad-based health group able to serve a wide range of the public’s health needs . . . The potential benefits of bringing health and fitness services and more traditional healthcare services closer together are enormous.”

RBS bought Cannons in 2001 when, with PPM Capital, it backed a £360 million management buyout led by Harm Tegelaars, the founder, who moved to a nonexecutive role two years ago.

However, its equity value was almost erased as increasing competition exacerbated difficult trading conditions. RBS asked Hawkpoint, the corporate finance boutique, to review its options last year. The process generated interest from suitors including MidOcean Partners, the private equity firm behind LA Fitness.

Nuffield is acquiring 52 Cannons Health & Fitness clubs, together with a division that manages 15 local authority facilities that trade primarily under the Courtneys brand. The combined group will have a turnover of almost £600 million.

The sale of Cannons is the latest in a series of deals in the health clubs market. London & Regional acquired Next Generation Clubs and David Lloyd Leisure, while Bannatyne’s Health Club swallowed the LivingWell chain.