NASDAQ-listed Catapult announced last week that it had replaced Deloitte with Stonefield Josephson, a firm ranked 67th in the US. Not many companies trip down the league table when choosing a new auditor. But that wasn’t the most remarkable thing about this decision. It was the detail that California-based Catapult was willing to go into in an SEC filing.

‘Its Audit Committee believe that, by engaging Stonefield Josephson, Inc. as the Company’s independent registered public accounting firm for the current fiscal year, the Company will realize significant savings on these expenses without negatively affecting the quality of the audit and related services.

‘Based on estimates from the two firms, the Company currently believes that the potential savings for fiscal 2008 from the change in firms will be in the range of 43% to 49%. The Company cautions that this is an estimate only and is based on the Company’s current understanding of the information it has received from the two firms and the scope of the work that will be required.’

So Catapult’s decision was (a) based on a desire to save money (it expected to shell out out just shy of a million dollars to Deloitte for its audit in 2008) and, crucially, (b) based on the belief that a modestly-sized firm can offer the same service quality as a Big Four firm at a significantly reduced cost.

The fact that it was willing to say so is to its credit and hopefully will pave the way for other companies to be more transparent about their thinking on auditor engagement.

Before I get attacked for massively over-simplifying the issue (to which I plead guilty) and being partial (my plea there is not guilty), that’s not a call for more companies to drop the Big Four. It is a call for more businesses on both sides of the Atlantic to be more open about why they choose and review auditors.

I have said several times that I can’t see a regulatory solution to the audit choice debate. This is the best market one I’ve seen yet.