The tournament was divided into three phases. The first phase had 19 teams divided into four round-robin groups of four and one group of three (defending champions Nacional received a bye to the second phase). Each group had clubs from two countries. The winners of each group advanced the second phase. Five teams joined the defending champions in two round-robin groups of three. The winners of each group advance to play in the finals. The winner of the finals, and tournament champions, are determined by points (two for a win, one for tie).