Manchester United manager Sir Alex Ferguson says he has shelved all thoughts of retirement. On Sunday Ferguson became the longest-serving manager in United's history and on New Year's Day will celebrate his 69th birthday. It is almost nine years since he famously reversed a long-standing plan to quit. Yet the fire still burns fiercely in the Scot's soul and with his team now favourites to secure a record 19th league championship this season and having completed a smooth passage to the last 16 of the Champions League, Ferguson insists thoughts of walking away have long since been banished. "The older you get the more worried you are about retiring," he told MUTV. "You start to realise that whilst you have got your health and good fitness, you should carry on in your job. All thoughts of retirement are in the back of my mind. "It (saying he was going to go) was a mistake. At the time there were some reasons for it. It was one of those things." Ferguson's record includes 11 titles and two Champions League triumphs, pushing him right to the forefront as one of Britain's most successful managers. He still has reservations about some decisions though, even when he gets them right. Most recently it was dumping Dimitar Berbatov on the bench for last week's win over Arsenal. It was a very brave move considering the Bulgarian became only the fourth player to score five in a Premier League match during the previous outing against Blackburn. Ferguson's move was justified by the 1-0 win that took United top of the table. But telling Berbatov was not very easy. "Management is about making decisions," he said. "Sometimes they are positive and good. Sometimes you feel you have made the wrong decision and should have attacked it a different way. "Picking teams for instance. We made the decision the other night to leave Berbatov out of the team. It was not an easy one and was very difficult to explain. "The only way I could do that was by saying I felt it was going to win us the match. Although it was proved right you are never sure." Is Ferguson's decision-making still as good as ever? Have your say.