Andy Murray, the world number three in tennis, has tweeted:
What a legend sir alex ferguson! Shame that he is retiring from management but what a career its been.. Who's next for united?#irreplaceable
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.