Manchester United have insisted that they achieved all their goals in the summer transfer window despite supporters feeling underwhelmed at the business done by David Moyes and Ed Woodward.

With an incoming manager and chief executive at the end of last season, it was always like to be a difficult summer for a club which has always strived to attract football's biggest stars.

But Moyes and Woodward have faced heavy criticism after only landing Marouane Fellaini during the three-month window - and spending £4m more than his original release clause to do so.

But the club have now sought to explain their actions to the fans by writing a blanket response to any criticism, in a letter which states: "The club had two main priorities for the transfer window. The first was to keep Wayne Rooney. He is a world-class player and the manager is very keen to have Wayne as a key part of the club's drive to retain the Premier League trophy. That aim was fulfilled.

"The second priority was to add a midfield player, and the capture of Fellaini has met that need."

The correspondence also pointed out that with Wilfried Zaha and Adnan Janazaj coming into the mix at Old Trafford the squad would take a different look to the one which lifted the title last season.

"The club has invested over £40m acquiring new players this summer, as well as re-signing Nani on a long term deal - more than it has traditionally spent on transfers.

"Additional resources were there to add to that but it was not possible to agree with other clubs for the right players to leave. The key point there is that the players we buy have to be the right ones for Manchester United; not just any player."

It was always going to be difficult for United to change managers and the longer Sir Alex Ferguson went on at the club - eventually lasting 26 years before retiring at the end of last season - the more impossible it looked for any manager to replace the club legend.

But the United owners are insistent that they are fully behind Moyes to bring long-term success to the side and were pleased to see that under pressure the Scot didn't panic-buy.

"The club has always backed the manager in the transfer market, as Sir Alex has said on many occasions, and it will continue to do so," the letter explained. "The club has demonstrated its belief in, and commitment to, David Moyes through the award of a six year contract.

"Allowing him to shape the future Manchester United team is a long-term project, not an eight-week panic. He must be given time to assess his new squad and come to his own decisions on which players he feels will strengthen it."