The north-east club's 2-1 home defeat by fellow strugglers Wigan on Saturday left Sunderland 16th in the English Premier League and just two points above the relegation zone.
Former Manchester United defender Bruce joined the Black Cats from Wigan before the 2009/10 season and struggled to win the affection of some Sunderland fans who resented his boyhood support of local rivals Newcastle United.
But, despite some of the taunts aimed at Bruce at the weekend by angry fans at the Stadium of Light, Dallas-based businessman Short said his was not a knee-jerk decision.
"This has been a difficult time for everyone at Sunderland and is not a situation that any of us envisaged or expected to be in," said Short in a statement released on Sunderland's official website.
"It is my job as chairman to act in the best interests of our football club at all times and I can assure everyone that this is not a decision I have taken lightly.
"Sadly, results this season have simply not been good enough and I feel the time is right to make a change.
"Steve has acted with honesty and integrity throughout, which is testament to the character and commitment he has shown during his time at Sunderland.
"I would like to personally place on record my thanks to him for his significant contribution to our football club over the past two and a half years and everyone here at Sunderland naturally wishes him the very best for the future.
"I would also like to thank our fans, who have endured a trying start to the season. Their support continues to be the driving force behind our club and is vital as we now look to the future."
Source: AFP
Source: AFP