John Flint is giving up the role he has held for a year-and-a-half "by mutual agreement with the board".

He will immediately cease his day-to-day responsibilities at HSBC, but will help with the transition as Noel Quinn takes over as interim chief executive.

Chairman Mark Tucker thanked Mr Flint for his "commitment" and "dedication".

However, he said: "In the increasingly complex and challenging global environment in which the bank operates, the board believes a change is needed to meet the challenges that we face and to capture the very significant opportunities before us."

HSBC made the surprise announcement as it reported a 15.8% rise in pre-tax profit to $12.4bn (£10.2bn) for the six months to 30 June.

Mr Flint, who has worked at HSBC for 30 years, said: "I have agreed with the board that today's good interim results indicate that this is the right time for change, both for me and the bank."

The 51-year-old ran the bank's retail and wealth management business before taking over as chief executive last year. At that time, Mr Flint was seen as a safe choice for the top job.