South Korean exports during the first 20 days of this month rose 1.2 percent over a year ago in U.S. dollar terms, customs data showed on Friday, while imports slipped 4.6 percent over the same period.Korea Customs Service indicated South Korea posted a trade 1.84 billion US dollars surplus for the October 1-20 period. In September, exports fell 5.9 percent while imports inched down by 1.7 percent in annual terms. Full months figures for October will be released on November 1.