Manchester United paid 13.4 million pounds ($24.2 million) to agents on top player transfers from 2001 to 2004 and did not break any rules, the English soccer club said on Tuesday in response to investor criticism.

The world's richest soccer club said an internal review sparked by criticism from its biggest shareholders, Irish race horse owners John Magnier and J.P. McManus, had looked at 21 player transfers worth 158 million pounds excluding agent fees.

It found the club's established internal practices had been fully adhered to and all documentation had been completed in accordance with Football Association (FA) rules.

Manchester United said the deals it examined included the 2.3 million pound purchase of United States international goalkeeper Tim Howard from the New York/New Jersey Metrostars. This amount included 700,000 pounds for agent Gaetano Marotta.

"Although the agent's fee was large as a percentage of the overall deal, the board believes the total cost represents good value," the club said.

Manchester United said it believed the commission on the transfer was shared with other parties but had no proof.

The club was also satisfied there were "no untoward issues" in its dealings with sports agency Elite Sports, where Jason Ferguson, son of team manager Alex Ferguson, is a director.

"Nevertheless, the board recognises the concerns over the connection between Elite and the club manager," the 15-times English champions said in a statement.

Manchester United said it would not allow Elite Sports, which represents 13 of its players, to act for it in future and would publish full details of any dealings it had in which Elite Sports acted for a player or another club.

It also pledged to revise its existing transfer procedures by placing tighter rules on the appointment of agents and stricter limits on how much they could be paid.

"I am satisfied that we have complied with the relevant regulations, but accept that there are things we could do better to protect the reputation of the club," chairman Roy Gardner said.

Magnier and McManus, who own 28.9 per cent of Manchester United shares, were examining the club's findings, a source close to the Irish pair told Reuters.

"McManus and Magnier will put forward any views when they have their next routine contact with the board. It would be inappropriate to comment before then," the source said.

Like another big investor, U.S. sports tycoon Malcolm Glazer, Magnier and McManus have been steadily increasing their stake in Manchester United, sparking market speculation of a possible takeover bid.

Sources close to the matter have said the Irish duo are long term investors and that any takeover bid was more likely to come from Glazer, owner of American football's Tampa Bay Buccaneers.