Fitness technology giant Gantner has been acquired by the private equity backer behind high street food chain EAT.

Investment company Ardian has agreed a management buyout of Gantner from former owner Identec Group AG for an undisclosed amount. As part of the transaction, which is subject to regulatory approval, the existing Gantner management team will invest in the company.

Gantner is a major supplier of contactless wristbands, access control, payment and staff time recording solutions to the fitness industry, working with chains such as Virgin Active, Fitness First, Fresh Fitness and MacFit. The company recorded 2015 full-year sales of €36m ($US40m, £28m) – up 20 per cent on the previous year.

“With our long-term experience, our in-house R&D skills and our excellent team, we offer our clients the most innovative product solutions combined with state-of-the-art technology,” said Gantner MD Elmar Hartmann.

“In Ardian we have found an entrepreneurial partner who not only understands our business but who will also support us in accelerating Gantner’s international expansion. We look forward to continuing our successful growth path together with Ardian.“

The deal marks the 13th investment to be made from Ardian’s €500m (US$555m, £389m) Expansion Fund III and follows its €51m (US$57m £40m) investment in high-street sandwich chain Eat in May 2015. Ardian was previously a backer of sports drink business FitnessBoutique, before recently selling its stake back to the company's founders after five years.

“The success of Gantner is down to its innovative products, an experienced team with excellent know-how, and long-term customer relationships,” said Dirk Wittneben, head of Ardian Expansion in Germany.

“We look forward to working alongside management to build on the existing product portfolio and to provide support for the company’s international growth. Additionally, we will offer Gantner support through our international network as it moves to enter new markets.“