And the Manchester United Supporters Trust, which is running a vocal campaign to bring about a change of ownership, says membership has doubled to about 100,000 in the past month, with much of that growth coming following the "Red Knights revelation".
Ferguson has some friends among the Red Knights and has said he has "no problem" with the protestors.
"There were plenty of green and gold scarves on Sunday [in the Carling Cup final win over Aston Villa] and I was delighted to see them supporting the club," he said.
"We are quite happy. As long as they are supporting Manchester United they can wear whatever they like.
"I have no issue with the Red Knights. I know some of them. I don't deny them the right to protest.
"If they want to try and buy the club that is entirely up to them."
According to The Observer, senior City financers allied to the consortium had claimed Ferguson was supporting the controversial bid.
The so-called Red Knights include Goldman Sachs economist Jim O'Neill, acting in a personal capacity, lawyer Mark Rawlinson and financier Keith Harris.
Man Utd fans have staged 'green and gold' protests against the Glazers
It has been reported that 60 investors have pledged up to £1.5bn ($2.26bn) to buy the club, but a statement from the Red Knights last week said the figure was purely speculative.
US sports tycoon Malcolm Glazer, who bought United for £800m, has said the club is not for sale, while the club's chief executive David Gill said the owners were "running the club the right way".
According to the latest accounts that were released in January, debts at United's parent company Red Football Joint Venture have increased to £716.5m.
Red Football Joint Venture is owned by the Glazer family and secures its debts against the football club, but the accounts also confirmed that six of Malcolm Glazer's children were each given loans worth £1.67m from the parent company.
All are directors of Red Football, and such a practice is legal, but Harris, who is the head of merchant bank Seymour Pierce, has said it did "not create a good impression of the directors' governance of the company".
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