Mike Hicks, head of lending at Charity Bank, said his organisation could support charities that were unable to get help from commercial lenders.
"Any charity that has funds stuck with Icelandic banks and is watching its cash flow slowly drying up is unlikely to be an attractive proposition to a commercial bank in current market conditions," Hicks said.
"We are part of the banking sector but, as a charity, we also want to be part of the solution," he added. "We should be delivering on our mission and offering assistance to charities that are feeling the squeeze as a result of market failure."
Malcolm Hayday, chief executive of Charity Bank, has written to umbrella body the NCVO, chief executives body Acevo, the Charity Finance Directors' Group and the Charity Commission to outline his organisation's offering.