Niall Quinn's quotes on Keane's departure
"Roy's decision sums up his desire to always do what is best for the club, despite the club's efforts to keep him," Sunderland chairman Niall Quinn has said.
"Roy deserves huge respect for his contribution and the manner in which he guided the club from the depths of the Championship back to the Premier League.
"His winning mentality and singled mindedness were just what this club needed. Even in his departure he has been more concerned for the welfare of the players and his staff than himself.
"The board has reluctantly accepted his decision and wish him and his family well for the future."
Keane had been in charge at The Stadium of Light for just 27 months and helped guide the club back to the top-flight by winning the Championship title last season.