Steve Gibson: "This has been the most difficult decision I have had to make in all the time I have been in football.
"Gareth has given Middlesbrough Football Club magnificent service as a skipper and, in very difficult circumstances, as manager.
"I appointed Gareth in a situation that was greatly unfavourable to him.
"He is a good man and has all the qualities and integrity that we wanted in a manager.
"However, the time is right for change and that change has had to be made.
"Gareth will always be welcome at our football club. English football needs people of his stature and we feel certain that this experience will serve him well.
"Gareth deserves another opportunity once he has had the chance to rest and refresh himself."