A foreign currency dealer of the Korea Exchange Bank talks on a phone in front of screens displaying the Korea Composite Stock Price Index (KOSPI, L) and the exchange rate between South Korean won and U.S. dollar at the bank's dealing room in Seoul August 3, 2011. South Korean shares saw substantial losses on Wednesday, extending declines, as concerns over the health of the world economy continued to weigh on exporters. REUTERS/Truth Leem (SOUTH KOREA - Tags: BUSINESS)