Commonwealth Bank is set to lose one of its most senior executives, after Ian Saines, the head of the bank's institutional and markets arm, handed in his resignation.
Mr Saines on Monday became the second top executive to announce his departure since Ian Narev was appointed chief executive in late 2011, following last year's resignation of retail boss Ross McEwan, who now runs RBS.
After working with the country's biggest lender since 2004 and overseeing a push into areas that traditionally have been the domain of investment banks, the 51-year-old Mr Saines said he was moving into a "new phase" in his career.
He will remain with CBA until the end of this year, and the bank is expected to begin a global search for a replacement immediately.
It is understood he has not yet signed up for a new job, and the decision was driven by a desire to consider other career opportunities in finance or other industries.
"I consider my current position to be one of the best in Australian banking, so a decision to stay would have been easy," Mr Saines said in a statement.
"The strength of the business and the outstanding quality of its talent gives me the opportunity at this time to move on to a new phase in my career."
Mr Saine's division is the third largest in the CBA in terms of annual earnings, after its retail bank and its business and private banking arm. Mr Saines' total remuneration package was $4.5 million last financial year.
Since he joined the bank from BT in 2004, the lender has taken an unusual strategy for a local big bank of seeking to become a "universal wholesale bank" - providing services such as institutional broking, as well as standard banking offerings, such as lending, deposit and payment services.
In the latest annual results the division was one of the strong performers, with 10 per cent annual growth in profits to $1.2 billion.
CBA's push to become a universal wholesale bank has occurred as investment banking and broking is experiencing tighter margins.
The bank, however, has argued that it is common for overseas banks to also offer these services.
CBA shares rose 1 per cent to $73.86.