The preliminary stages of the 2010 Copa Sudamericana de Clubes are: * First Stage, contested by 16 teams in 8 two-legged ties. The winner of each tie will advance to the Second Stage. * Second Stage, contested by 30 teams, 8 of whom advanced from the First Stage, in 15 two-legged ties. The winner of each tie will advance to the Round of 16, joining the defending champion, LDU Quito.