The club announced the death shortly after Pagan's family became aware, and the Pirates observed a moment of silence before their Tuesday game against the D-backs at PNC Park. No cause of death was given.
The Puerto Rico native -- who played for the Giants (1959-65), the Pirates (1965-72) and the Phillies (1973) -- helped lead Pittsburgh to the World Series in 1971, and was part of National League pennant-winning clubs with the '62 Giants and the '70 and '71 Pirates.
His eighth-inning double in the 1971 World Series finale gave Pittsburgh a 2-0 lead against Baltimore, and the Pirates went on to win, 2-1.
In 1962 with the Giants, he hit .259 and drove in a career-high 57 runs. He hit seven home runs that season, just two short of his career high, set with the Pirates in '72.
Pagan finished his career as a .250 hitter with 52 home runs and 372 RBIs in 15 big league seasons.