CBOT soybean futures closed lower on Friday evening, declining in thin post-holiday trading as favorable weather conditions in South America intensified competition for U.S. soybean exports from Brazil. U.S. soybean export sales have recently declined, with the USDA export sales report showing that net soybean export sales for the current marketing year in the week ending December 18 reached 987,100 tons, a 59% decrease from the previous week.