Four senior partners at Big Four accountancy firm Ernst & Young (EY), including a leader in the firm’s compliance function, have left the company because of spiralling repercussions from a costly compliance failure. EY failed to follow U.S. and U.K. rules on lead auditor rotation, designed to ensure the independence of those responsible for issuing external audit opinions.

Ruth Prickett graduated from Cambridge University with a BA hons in History and has specialized in business and finance journalism for the past 20 years. She was editor of Financial Management, the magazine...