Commonwealth Bank of Australia Managing Director and CEO Ian Narev will retire by the end of fiscal 2017-18.

CBA Chairman Catherine Livingstone said the exact timing of Narev's retirement would depend on the result of an "ongoing comprehensive internal and external search process."

Livingstone made no mention of the reason for the retirement, but instead cited the bank's CEO succession planning and the need to provide certainty about Narev's tenure for the business.