Ferguson blasts Liverpool owners Manchester United boss Sir Alex Ferguson has criticised Liverpool's American owners for the way they have undermined manager Rafa Benitez.
Tom Hicks and George Gillett upset the club's supporters after admitting they had sounded out Jurgen Klinsmann as a possible replacement for the Spaniard.
"What happened was a bad piece of business on Liverpool's part, no doubt about that," Ferguson commented.
"That can be very upsetting. You should let a manager get on with his job."
Sir Alex is the longest-serving manager in English football, having been appointed at Old Trafford in 1986.
In that time he has become the most successful manager in British football history.
Under his stewardship, the club has won nine Premier League titles, five FA Cups, two League Cups, the European Cup, the Cup Winners' Cup, the Super Cup and Inter-Continental Cup with players.
Since Benitez took over at Anfield, Liverpool have won the FA Cup and Champions League.
But that has not prevented him having a high-profile falling out with the club's owners, and Ferguson said their lack of backing for their man did not make Benitez's job any easier.
"At big clubs, it's absolutely paramount that the board show their class," said Ferguson.
"Arsene Wenger has had great support at Arsenal and I've had great support, too, ever since I came here. So there's a certain type of unity there."
BBC Sports