National Australia Bank, the country's largest lender which has been hit by a A$360m (€217m) loss from rogue currency options trading, has been forced to cancel a share buy-back programme and abandon its internal market risk capital models.

The news comes on the back of a damning report on the currency options fiasco from the banking supervisor, the Australian Prudential Regulation Authority, which has imposed a series of severe restrictions on NAB. It has laid down a list of measures the bank must implement to ensure sound risk management and shore up its capital adequacy ratio.