Its auditor, Deloitte, is preparing the Fitness First accounts for the year ending 31 October using international financial reporting standards (IFRS) for its leases in 20 countries. The Dorset-based company is owned by private equity firm BC Partners, which bought it from Cinven in 2005. Fitness First founder Mike Balfour still holds a small stake in the firm but quit the board last year following a disagreement with BC. Industry sources said the change would mean Deloitte having to make separate calculations on the leases of all the company's 550 gyms. The impact of the calculations on the 2010 accounts is expected to dictate the listing plans. A successful flotation, which would help wipe out around 200 million of the firm's 550m debt, would see BC reducing its 80 per cent stake but retaining majority ownership. The group last month posted a 2009 pre-tax loss of 241m, almost double the 2008 loss. But it reported improved revenue and operating profit despite closing six clubs last year and losing around one in 15 members. The industry has struggled to retain customers since the financial downturn began, with David Lloyd reporting losses for 2009 and Virgin Active last week postponing a 1 billion flotation.