I have a similar situation. Did you find a solution? Please advised.
Have you tried Bibby Financial Services - this is an international financing firm that should be able to help you. They have offices in Florida and the UK - might have some elsewhere. But, they cover the world. They primarily finance accounts receivables but do do international letters of credit.
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To clarify I need someone that will lend the money against this 10 million letter of credit even if it is not the entire amount.