Venturesome, Charities Aid Foundation's social investment fund, has committed more than £1.5m to charities since its launch in 2002.
Thirty organisations have benefited from the fund, which makes unsecured loans and investments in voluntary organisations considered too risky by mainstream financial institutions.
Director John Kingston said: "Venturesome is an R&D pilot. The 30 commitments in 18 months shows that smaller charities are keen to explore new ways of raising funds, and that there is a gap between grants and bank loans that we can fill."
Its latest lending deal is a £250,000 loan to a charity hit by the freeze on grants by the Diana, Princess of Wales Memorial Fund in July.
The deal has helped Escape Artists, a Cambridge-based arts organisation that works with ex-prisoners, young offenders and young people at risk, to stave off redundancies and cutbacks.
The charity was due to receive a £180,000 grant from the Diana fund, but this was put on hold because of the trust's failed lawsuit against US company Franklin Mint over the sale of Diana memorabilia.
"The freezing of the grant plunged us into a state of crisis," said director Matthew Taylor. "We spent most of the summer involved in emergency fundraising and short-term contracts in order to generate income."
He said that without the loan from Venturesome the charity would have had to make staff redundant and abandon projects.
"This is something we would never have obtained from a high street bank," said Taylor.