Prince Daniel of Sweden has sold his Balance chain of health clubs to Nordic gym giant SATS for an undisclosed sum.

Balance, which has a focus on group and personal training, operates three premium sites in Stockholm with a total membership of around 7,000.

The company was founded by Daniel Westling – who has since become Prince Daniel after marrying Swedish Crown Princess Victoria – in 2006. He kept his ownership of the company after his wedding in 2010, but has now decided to sell the business.

The prince enjoyed a long career in the fitness industry before royal duties meant he had to give up day-to-day work, having established his first company in 1997. It was his work as a fitness trainer to Swedish celebrities that first introduced him to Princess Victoria in 2001.

The acquisition strengthens SATS' hold on the premium segment of the Swedish fitness sector and is part of the group's strategy to develop its personal training offer.

Following the deal, SATS operates 75 sites across Sweden.

"Our growth strategy is based on growing even more at existing locations and growing through a broadened offer that attracts many different target groups," said Linda-Li Cederroth, country manager for SATS Sweden.

"Personal training is one of our strongest growth areas. Balance has a well-functioning concept for personal training, so the acquisition will be a natural addition to our existing business."