The new deal will keep the Republic of Ireland international at the club until 2012.
“I am very happy to commit my future to United,” he told United’s official website.
“Last season I enjoyed every opportunity and when I got my chance I wanted to prove what I could do. I hope to continue that this season.”
“Darron was one of the young players who emerged last season as a United first-team player,” said United boss Sir Alex Ferguson.
“His appearance ratio did not really reflect the high regard in which we hold him, as he has constantly worked hard to challenge for a first-team spot.”
