Nautilus has acquired Octane Fitness from private equity firm North Castle Partners in a deal worth US$115m (€107m, £78m).

Nautilus – which has a fitness brand portfolio comprising Nautilus, Bowflex, TreadClimber, Schwinn, Schwinn Fitness and Universal – has been seeking a strategic acquisition for more than 18 months.

Nautilus believes the takeover of Octane – known for its Zero Runner and XT-One cross trainer – will help it to accelerate growth by being able to extend into higher price point products, penetrate new channels of distribution and expand into new international markets.

"This transaction adds a leading fitness brand, unique products and technologies, broadens distribution and deepens our talent pool,” said Nautilus COO Bill McMahon.

“Octane is highly complementary from both product and channel perspectives, and we believe this acquisition will create numerous revenue synergies.”

Having founded Octane in 2001, Dennis Lee and Tim Porth will now join the management team at Nautilus, according to Nautilus CEO Bruce M. Cazenave.

The deal adds to the flurry of activity in the fitness supplier market over the past six months as companies seek to enhance their portfolio. Life Fitness recently expanded its presence in the active ageing fitness market through the acquisition of specialist equipment supplier SCIFIT, while Precor upped the ante on its functional fitness ambitions by buying Queenax.

Amid the activity in the supplier market, the decision by North Castle Partners to sell Octane signals a shift by the private equity firm to focus on its operator investments. Having previously been involved with fitness brands including Equinox and Curves International, North Castle believes its invetsment in Barry’s Bootcamp can help the boutique fitness brand realise its aggressive expansion plan for 2016 under CEO Joey Gonzalez.

On the decision to sell Octane, North Castle Partners managing director Alison Minter said: "As a focused fund with nearly two decades of experience in the Healthy, Active and Sustainable Living market, and eight investments in the fitness sector over the last 15 years, we were able to leverage deep expertise in the fitness industry in partnership with the Octane team to build on their track record of innovating award-winning, patent-protected zero-impact cardiovascular fitness products."