The big four accounting firms face a threat to their dominance in the blue-chip audit market after Grant Thornton and RSM Robson Rhodes unveiled a merger plan to create the sector’s fifth biggest firm by revenues. It is the biggest merger in UK accounting since PwC was created in 1998. The combined firm would have had turnover of £361m last year, leapfrogging BDO Stoy Hayward to become the biggest accountant outside PwC, Deloitte, KPMG and Ernst & Young. But its revenue is still one-third of that at E&Y, the number four firm.
