KOREA - Foreign banks feel the FX strain

South Korean authorities have called for greater disclosure from banks on external debt as they fret about the rapid growth in overseas borrowing. At the heart of the problem is shipbuilders, whose hedging against an appreciating won is putting upward pressure on the currency. While the government denies it is intervening in the FX market, bankers beg to differ. But are they just irritated at missed opportunities for arbitrage? Rupert Walker reports.