Citing recent surgery after a prostate cancer scare, Mr Yule said he had decided that his “own health and family must come first in future”.
The former oil and gas worker joined Aberdeen in 20120 as executive vice chairman, and was instrumental in helping to reshape the club, foster better relationships with the fans and push forward plans for the new community hub, training complex and stadium at Kingsford.
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Chairman Stewart Milne paid tribute to Mr Yule, telling the club’s website: “George has played an important role in the day to day operations of the club for almost six years.
“George very much appreciates the scale of the task that lies ahead for the club, not only in delivering the community and training facilities, as well as the new stadium, but also in substantially growing the Club so that it can retain its position at the top of Scottish Football and continue to make its mark in Europe.
“I have enjoyed working with George during that time, and personally appreciate all that he has contributed to the club’s progress over his time with us, we are indebted to him, and wish him all the best for the future.
“He may be leaving his current role, but we are comforted in the knowledge that he will continue to play a role both as a fan and an ambassador of the club.”
Mr Yule added: “As a life-long Dons fan It’s not been an easy decision to make and I will certainly miss mixing and working with footballers, business colleagues and our passionate supporters on a daily basis.
“Although I’m heading towards full recovery [after the cancer scare], the absence gave me an opportunity to re-evaluate my priorities and I decided that my own health and family must come first in future.
“It’s been an honour and a pleasure to serve the club and I have no doubt that AFC is in a strong position across all areas, with plans now well underway for the new training facilities, a very strong and committed football management and back room staff, and a hard-working group of good people across all departments.
“I’m grateful to many people both within and out with the club for their efforts and ongoing support in enabling Aberdeen to reinstate and consolidate its rightful position at the top end of Scottish football and I wish Derek, Tony, the board, executive team, and all of my good friends at the club the very best in future.