Former Manchester United footballers Danny Simpson and Ravel Morrison, who both played under Sir Alex Ferguson, tweeted their surprise and sadness that the manager is to retire:
Wow I can't believe Sir Alex has actually retired. It doesn't seem real. He's an absolute legend n I'm privileged to say I worked with him
sad new Alex ferguson will retire ????
Sir Alex Ferguson's brisk way with words has influenced the way we talk about football.
A timeline of the life of outgoing Manchester United manager Sir Alex Ferguson.
A special photo gallery of Sir Alex Ferguson's career at Manchester United as he steps down from his post as manager of the club.