Ferdinands contract expires in July and he has revealed he will not be signing an extension after regularly being left out as Phil Jones, Jonny Evans and Chris Smalling have been preferred to him at centre half this term.
In a statement on his website, Ferdinand said: I have thought long and hard over the last few months about my future, and after 12 fantastic years playing for what I regard as the best club in the world, I have decided the time is right for me to move on.
Ferdinand made his last appearance for United on Sunday when he played in their 1-1 draw at Southampton on the final day of the Premier League campaign.
His departure brings an end to a glorious 12-year stay at United, during which time he won six league titles, two League Cups, one Champions League and a Club World Cup.
Ferdinand made 454 appearances, scoring eight goals, following his then British record 30 million ($50 million, 36 million euros) transfer from Leeds United in 2002.
The ex-England captain has no desire to retire and is now looking for a new club. I joined Manchester United in the hope of winning trophies, and never in my wildest dreams could I have imagined how successful we would be during my time here, Ferdinand added.
There have been so many highlights, playing alongside some great players who have become good friends, winning my first Premier League title and also that fantastic night in Moscow (beating Chelsea to win the Champions League) memories that I will cherish forever.