Operator Tone Leisure is to become a wholly-owned subsidiary of GLL, as the burgeoning not-for-profit enterprise continues to expand.

Under the agreement, which commences on 1 June 2015, Tone will continue to directly operate its 13 leisure and sporting facilities across the south west of England until 1 December 2016, when a full merger is planned with GLL. Having formed in 2004, Tone has quickly grown to comprise 600 staff, with a yearly turnover of £7.8m.

The deal follows a flurry of activity involving GLL – which recently acquired

North Country Leisure and also announced a merger with Carlisle Leisure Limited – as the enterprise grows rapidly beyond its London heartland. GLL now operates more than 170 leisure centres across the UK.

GLL said the Tone tie-up is a natural fit as both operators are charitable social enterprises and leisure trusts with similar values and a “mission to ensure the whole community benefits from high quality, affordable leisure services.” The Tone board structure, which connects the local service with its communities, will remain in place until the full merger is completed.

"We are very pleased that Tone will join the GLL family, where we both share the same core values, to increase physical activity, reduce health inequalities and improve social inclusion,” said GLL managing director Mark Sesnan, who was this week elected to the ukactive Board of Directors.

"This is a great opportunity for Tone Leisure to team up with the UK's largest and most successful leisure charitable social enterprise, to further strengthen and develop services, as well as retaining local jobs - all whilst benefiting from the knowledge, experience and economies of scale of GLL."