In July Greece's rescuers agreed that it would need a new bail-out plan to include a "voluntary" debt restructuring by private Banks along with fresh dollops of official funds.

But in fiscally troubled countries like Greece and Portugal, which are having to be rescued with official bail-outs, bank-debt maturities have shortened dramatically.

Earlier a senior German official said that a bail-out for Greece could involve loans or a commitment to buy Greek sovereign debt.