US private equity firm CCMP Capital Advisors has signed an agreement under which UK-based affiliates of CCMP will acquire Pure Gym, the budget gym operator.

Financial terms of the transaction were not disclosed but a spokesperson for CCMP said the deal will support Pure Gym's aggressive expansion drive across the UK.

Pure Gym currently has 45 locations and CCMP will support a rollout strategy which will include the opening of an additional 40 new gyms over the next 12 months.

Thomas Walker, managing director at CCMP's London affiliate, said: "We're delighted to be partnering with management to accelerate the growth of Pure Gym, an outstanding business with tremendous customer appeal.

"Pure Gym's relatively low market penetration and the widespread appeal of a high-quality low-cost fitness option, we believe there is a significant opportunity to expand Pure Gym aggressively across the UK."

The transaction is expected to close in the second quarter of 2013, subject to closing conditions.

Canaccord Genuity acted as financial advisor and Travers Smith acted as legal advisor to Pure Gym, and Liberty Corporate Finance acted as advisor to Pure Gym's management. Kirkland & Ellis acted as legal advisors to CCMP.

Pure Gym was founded by Peter Roberts in 2008. CCMP specialises in upper-middle market buyouts and growth equity investments of US$100m (£65m) to $500m (£353m) in the US and Europe.