Complex sentence: IFTA, FIPESO, and FISE formed a liaison group, known as the Joint Committee of International Teachers Federations, later that year, but the American-dominated WOTP refused to join.
Split into simpler sentences: IFTA, FIPESO and FISE formed a liaison group, the Joint Committee of International Teachers' Federations, the same year. But the American-dominated WOTP refused to join.