Traders, who had been expecting a statement from France and Germany on Greece, were rattled when none materialised. Angela Merkel insisted that calls for Greece to quit the euro were wrong, arguing that the move would trigger a "domino effect very quickly". The German Chancellor said she and French president Nicolas Sarkozy had a scheduled call with the Greek prime minister on Wednesday. Fears of default have already gripped European banks. Experts warned that French banks, whose shares have plunged in recent weeks, might be forced to tap the markets for €20bn within the next few days.