The Echo understands his departure is completely amicable and he will not be leaving the club until the end of the year, which will allow time for a replacement to be found.

But there's no doubt his exit will be felt at the club where he has been a hugely discreet and dependable figure. Walker has accepted a new post outside of football.

Appointed by Bob Murray, he almost left the club, early in Niall Quinn's chairmanship as he looked to move his career in a different direction.

But he was eventually persuaded to stay by Quinn and has been heavily involved in the buying and selling of players in the Drumaville era.

In a statement Walker said: "After over ten years, I have decided to move on from Sunderland Football Club and seek a new challenge as Chief Executive of Omega PLC, having been a non-executive director of the holding company for nearly two years.

"I have thoroughly enjoyed my ten years in football and am confident that I am leaving the Club in an excellent position but think the time is right for me personally to broaden my horizons and accept a challenge in a new industry.

"I am very proud of the team of people that we have brought together at Sunderland over a period of time and it has also been a pleasure to work with Niall, Roy and the Board in the last two years since the takeover.

"I will be very sad to leave because of the people but I am sure that the professional team at Sunderland both on and off the pitch, will take the Club on from strength to strength."

Sunderland Chairman Niall Quinn added: "We successfully talked Peter out of leaving about 18 months ago as I really needed him to help us during the important and transitionary period after the takeover of the club by Drumaville.

"I have had to reluctantly accept his decision on this occasion but for the record although he is not one to look for credit, I think supporters should know of the important work he has done behind the scenes for this football club.

"Before we shook hands I did manage to sell him 2 season tickets though and we'll look forward to welcoming back for matches in the future!"