The US Chamber of Commerce has warned that the auditing profession is "on the edge of disaster" if regulators, business and auditors do not tackle the litigation liabilities faced by the "big four" firms.

It reflects concern over the possibility that one of them - PwC, Deloitte, KPMG or Ernst & Young - could collapse if multi-million dollar lawsuits brought for alleged negligence bring a firm's partnership to its knees.