Oxford United manager Chris Wilder has signed a new three-year contract at the Kassam Stadium.The U's boss had two years remaining on his existing contract but triggered a renegotiation clause following the team's promotion at Wembley in May. [LNB]Wilder told BBC Oxford: "I'm delighted to commit my future here. [LNB]"I'm grateful for the opportunity the chairman gave me. Hopefully we are repaying him for that faith and can keep it going." [LNB]After guiding Oxford back into the Football League the former Halifax manager insists he is still hungry for success. [LNB]Wilder said: "Nothing is completed in football. We can't stand still and we want more of what we had last season.[LNB] Our relationship is strong and a positive one and has enabled us to do things other managers and chairman haven't been able to Oxford chairman Kelvin Thomas "We have to keep driving forward. I'm really happy to be here and still have a big job to do." [LNB]Chairman Kelvin Thomas appointed Wilder in 2008 and says the deal is an important part of the long-term plans he has for the club. [LNB]"The manager is one of the most important pieces of that jigsaw," he said. "Our relationship is strong and a positive one and has enabled us to do things other managers and chairman haven't been able to." [LNB]Wilder, 42, took over in December 2008 with the U's in the bottom half of the Blue Square Premier and led them to just four points from the play-offs - after a five-point deduction. [LNB]The following season he guided them to a 3-1 play-off final win over York and they sit in the League Two play-off places after six games. [LNB]Assistant manager Mickey Lewis, first-team coach Andy Melville and goalkeeping coach Alan Hodgkinson have also signed new deals with the U's.