McCoist, who scored 355 goals in 581 appearances for the club, returned to Rangers as SmithÃ¢â‚¬â„¢s assistant in January, but originally said he did not expect to be put forward as a candidate for the managerÃ¢â‚¬â„¢s job.
Smith had considered standing down at the end of last season after winning his second successive SPL title since his return, but instead remained in the job as Rangers looked to manage a perilous financial situation.
Chief executive Martin Bain confirmed McCoist had accepted the role in December in a statement.
The 48-year-old will sign a one-year rolling deal, with current number three Kenny McDowall as his assistant, while Ian Durrant will become first team coach.
Ã¢â‚¬Å“We are delighted to confirm Ally as our next Manager when Walter Smith steps down at the end of the season,Ã¢â‚¬Â read a statement on RangersÃ¢â‚¬â„¢ website.
Ã¢â‚¬Å“First and foremost Ally is a passionate Rangers supporter who has been a loyal servant to the club both as a player and more recently assistant manager. He has contributed greatly to our success over the past four years and that is why we feel he is the right man to replace Walter.
Ã¢â‚¬Å“When Ally joined Walter as his assistant in January 2007 he was always being groomed as the next manager. He is the unanimous choice of the Rangers board to take the club forward next season and when I offered him the position in DecemberÃ¢â‚¬â€œduring our Champions League trip to BursasporÃ¢â‚¬â€œhe agreed immediately.
Ã¢â‚¬Å“Walter Smith is rightly regarded as one of the most successful managers in our proud history and what he has achieved during the 9-in-a-row years and more recently in his second spell as Manager is nothing short of remarkable.Ã¢â‚¬Â
McCoist said: Ã¢â‚¬Å“It was an honour to pull on the Rangers jersey during my playing career. I have enjoyed working with Walter, Kenny McDowall, Ian Durrant and the backroom team as assistant manager and to be confirmed as the next Rangers manager is a dream come true.
Ã¢â‚¬Å“Over the past few years I have been privileged to learn from one of the greatest managers in world football and WalterÃ¢â‚¬â„¢s record speaks for itself. The success he brought to Rangers during nine-in-a-row and the last four years in difficult times has been unbelievable and he has rightly gained the respect of everyone in the game.
Ã¢â‚¬Å“I am delighted to be following in his footsteps and I will do everything possible to bring further success to this club. I have said it many timesÃ¢â‚¬â€œRangers is a special club with a great history and tradition and this is the proudest day of my career.
Ã¢â‚¬Å“The fans have backed me for almost 20 years as a player and assistant manager and as a lifelong Rangers supporter myself I look forward to rewarding their loyalty by bringing silverware to our club.Ã¢â‚¬Â
McCoistÃ¢â‚¬â„¢s appointment was confirmed at a press conference at Ibrox on Tuesday afternoon, as Bain and the manager-in-waiting took questions from reporters.
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