Sunderland announced on Monday they had sacked manager Michael Beale after just 12 games in charge at the English Championship club.
The 43-year-old former QPR and Glasgow Rangers boss, who replaced Tony Mowbray at the Stadium of Light on December 18, lost his job following successive defeats to Huddersfield and Birmingham.
"We are disappointed that Michael is leaving Sunderland AFC," sporting director Kristjaan Speakman told the club's official website.
"Our desire is to improve and unfortunately that hasn't been evident. As such we take full accountability and feel that acting decisively is in the best interests of the club.
"This has been a difficult few months for Michael, who leaves with our best wishes for the future."
Assistant Mike Dodds will take charge for the rest of the season.
Beale won only four of the games for which he was in the dugout and lost six, one of them a tame 3-0 home defeat by arch-rivals Newcastle in the FA Cup third round.
Sunderland are 10th in the English second tier, four points off the play-off places with 13 games remaining.