Manchester United manager Alex Ferguson has said he is amazed at the "kamikaze" spending of some of his rivals.

"Over the last two or three years we have seen very wealthy owners become part of football clubs and therefore go on this kamikaze effort to spend their money," Ferguson said.

Ferguson, whose own spending during the transfer window has been a relatively modest £20 million compared to the £120-million-plus splashed out by neighbours Manchester City, did not name any club.

"It is amazing the amounts of money that are being bandied about in the present-day game," he told a news conference at Old Trafford where United presented new young signings Chris Smalling, Bebe and Javier Hernandez.

"Some people may think it could be dangerous. But if they have that kind of money, they are certainly using it.

"I don't see it abating. The kind of spending we are seeing at the moment will be here for two or three years, until such time as they understand you can't necessarily achieve all the time by spending."