The club said in a statement: "Blackburn Rovers are delighted to announce the appointment of Sam Allardyce as manager with immediate effect. Sam has signed a three-year contract."

Rovers were keen to make an appointment as soon as possible - especially as Allardyce had also been linked with the vacant position at Sunderland.

Blackburn chairman John Williams had said it would be a huge advantage for the new manager to be in position before Saturday's visit by Stoke.

Williams said: "You can't underestimate how much of a boost a physical presence could have on Saturday for what is an absolutely mammoth game.

"Everyone needs to know how big this game is as this is a time the club really has to come together."

Allardyce, 54, will be officially unveiled at a news conference at Ewood Park at 1600 GMT on Thursday.

His eight successful years as Bolton boss persuaded the Rovers board that he is the man to rescue Blackburn from the threat of relegation.

Blackburn are currently second from bottom of the Premier League with 13 points from 17 games.