His future with Wales was in doubt from the moment they failed to qualify for the World Cup.
However, Press Association Sport understands Bain is still pondering a range of options for an appointment he simply can not afford to get wrong after David Moyes and Simon Grayson both presided over disastrous spells at the Stadium of Light.
Jonathan Ford, Chief Executive of the Football Association of Wales, said: "We are extremely disappointed to see Chris' tenure as Wales manager come to an end".
Appointed as the late Gary Speed's successor in January 2012, Coleman will go down as the most successful manager in his country's history after leading Wales to the European Championship semi-finals a year ago.
"Kit Symons has also resigned from his position as National Team Coach and the FAW would like to put on record its gratitude for his commitment to the Wales National Team".
It is understood that caretaker manager Robbie Stockdale will remain in charge for Saturday's game against Millwall.
Disappointment followed as Wales failed to reach the 2018 World Cup finals in Russian Federation.
Those talks ended with Coleman opting to leave, having often spoken about hoping to one day return to the day-to-day demands of club management. Text me last night, all done, he arrived back at the hotel at 5 o'clock this morning.
Michael O'Neill, the Northern Ireland manager, Paul Heckingbottom, who is in charge at Barnsley, and Ally McCoist were among the other candidates considered for the Sunderland post but Coleman emerged as the clear frontrunner.
"But he had a big smile on his face, he's going to an incredible club and I think they'll like his football up there".