The announcement follows pressure from some fans about the club's failure to gain promotion from League One. In a statement, Donald said a new chairman would be appointed and he is still keen to sell the club.
The businessmen, who is chairman and majority stakeholder in Sunderland, said his 11-year-old daughter had been approached by three fans at a bus stop near to his Oxfordshire home, who were angry at reports he had taken money out of the club.
Sunderland owner Stewart Donald has insisted he is not looking to make a quick profit from selling the club