Arsene Wenger has suggested that Manchester United paid £10m too much for Rio Ferdinand following the England centre-back's £30m move from Leeds - a transfer which United today confirmed would be their only purchase this summer.

Wenger admitted he would have liked to have signed Ferdinand himself but he believes United have smashed the British transfer record on a player worth only £20m.

"They have bought a great player but they have paid a high price for him," said Wenger. "I'd like to sign Rio Ferdinand - but for £10m less.

"But I'm not surprised United have the most expensive players in Britain, as that reflects their financial strength.

"When you have a lot of money in your pocket you buy expensive. And that's what they have done."

In stark contrast to United's huge outlay, Arsenal have spent just £2.1m so far - on Lille defender Pascal Cygan.

But Wenger suggested that he would buy again before the beginning of the new campaign. "The chances are that we will buy a midfielder before the start of the season," he said. " I haven't made up my mind yet who that will be."

However, Manchester United chief executive Peter Kenyon today closed the chequebook for the summer, making Ferdinand United's only purchase of the close season.

"We're not looking for new players," Kenyon said. "We concentrated on what we thought was our single number one target and that was Rio."

Even though three first-team players have left Manchester United since the end of last season, and with Dwight Yorke also possibly on his way out, Kenyon feels the squad is big enough.

"There's a limit to the squad size you can have. Top players want to play football, they don't want to sit on benches and have rests.

"We've got a squad size which we're happy with. We've got Wes Brown and we've got John O'Shea who you would expect to feature more prominently.

"If you look at us we've probably got the best midfield of any team probably across Europe...we're great in every department.

"This was all about bringing in a quality player in defence. We never sat down and said we needed to bring in several players.

United are confident Ferdinand, whose fee could eventually rise to £33.3m depending on how well they do over the length of his five-year contract, will shore up a defence that leaked 45 league goals last season.

Kenyon said: "The decision was taken that we needed to strengthen the defence. Good central defenders are few and far between so it was a pretty small list and top of that list was Rio."

While no more players may be coming into Old Trafford, Yorke still appears to be heading out, even though Blackburn are refusing to meet United's asking price.

Kenyon claims a deal for the striker, who is out of contract next summer, could still be struck.

"Blackburn and ourselves have been having discussions and will continue to have discussions," he said.

"If we reach a deal we will do it. The gap between us is not as big as has been reported and we have both moved. Everything is possible."

Meanwhile Lazio president Sergio Cragnotti has denied that Juan Pablo Sorin is moving to Manchester United.

Reports in Italy claim that the centre-back was about to move to Old Trafford as a final payment for the transfer of Dutch defender Jaap Stam. But Cragnotti said: "Sorin won't move from Lazio. There's no discussion about that with Manchester United."