Sunderland have sacked manager Howard Wilkinson and his assistant Steve Cotterill.
Wilkinson had won just two league matches in 20 games at the helm as Sunderland slumped to two points adrift at the bottom of the Premiership.
The club's board announced on its website "that it was in the best interests of the club and its supporters to make a change immediately".
Sunderland chairman Bob Murray said: "The club and its supporters have faced disappointment over a drawn out period.
"This has been very difficult for everyone concerned but we are absolutely determined to arrest the decline and revive the club.
We will be appointing a successor before our crucial game against Bolton at the weekend
"We will be appointing a successor before our crucial game against Bolton at the weekend.
"The fans have been incredibly tolerant and supportive in the circumstances and I would like to thank them for that.
"We understand how people are feeling and regret this. We all want to see the team get back to winning ways and putting in the type of performances that will give the fans something to cheer about."
Vice-chairman John Fickling added: "It is important that the new manager can improve our league position in the short term and help re-establish the club.
"We know he will need to hit the ground running and as such we need to give him as much support as possible."
Wilkinson, the former Leeds and Sheffield Wednesday boss, left his job as England technical director to take up the Stadium of Light post in October 2002.
He took over from Peter Reid, who was sacked after more than seven years as manager at the club.
Cotterill took up his position as Wilkinson's assistant after leaving Stoke, who he joined in May after guiding Cheltenham Town from the Conference to Division Two.