Manchester United fans have secured a loan of up to £100m as part of a scheme to block a takeover bid by Malcolm Glazer. The Japanese investment bank Nomura has agreed to loan the money to the Shareholders United group as part of a plan to head off the bid by setting up an offshore trust to hold shares owned by fans.

The group must first persuade small shareholders to give their shares in the club to an investment trust that they would set up with the Independent Manchester United Supporters' Association. They plan to write this week to the 30,000 private shareholders in United to gauge support.

Using the shares as collateral, the offshore trust would use Nomura's loan to buy more of them: for every £1 of shares given by fans Nomura would lend the money to buy the same. This way, SU would hope to effectively double the fans' stake and make it big enough to block an approach from Glazer. The American needs the support of 75% of shareholders to complete his proposed £800m deal.

The chairman of Supporters United, Nick Towle, claims the group last week wrote to the Irish racing tycoons JP McManus and John Magnier - who own a 29% stake in United - to ask them not to make "hasty decisions" about selling their shares to Glazer.

Towle claims Supporters United will try to minimise the risk to shareholders of swapping shares for an indebted vehicle, and will be discussing the details with Nomura over the coming weeks. A spokeswoman for the bank said: "We are in active discussions, including the possibility of lending money to an investment trust."

Last week the Takeover Panel, the City's corporate finance regulator, ruled Glazer should have until May 17 to put forward his offer or leave the club alone.