Complex sentence: It gave provisional civil administration of Zone A (with Trieste), to Italy, and Zone B to Yugoslavia: in 1975 the Treaty of Osimo finally divided the former Free Territory of Trieste.
Split into simpler sentences: It gave provisional civil administration of Zone A (with Trieste), to Italy, and Zone B to Yugoslavia. Finally in 1975 the Treaty of Osimo finally divided the former Free Territory of Trieste.