The threshold for a company being regarded as a 'major audit' by the Audit Inspection Unit has dropped from £100m to £50m. The change reflects the fall in market capitalisation of AIM and PLUS-quoted companies over the past year and means that the proportion of these companies that remains within the AIU's scope will be 'broadly constant', according to the AIU's oversight body, the Professional Oversight Board. Given the current economic climate, the board has agreed that the AIU should consider audit issues such as going concern, fair value accounting estimates and disclosures and impairments of assets including goodwill and other tangibles when conducting its inspection work in 2009/10. Dame Barbara Mills, board chair, said: 'The board continues to have regard to the level of public interest involved and the need for proportionate and cost-effective regulation in determining which entities should fall within the scope of the AIU's work'.