Answer
Yes, one of Mariano Rumor's governments was a coalition government, specifically the Second Rumor government, formed after the 1972 general election in Italy. This coalition government included the Christian Democracy party, the Italian Socialist Party, and the Italian Republican Party. The Second Rumor government lasted from July 1973 to March 1974, when it was replaced by the Third Rumor government, a single-party government formed solely by the Christian Democracy party.