Maggio Musicale Fiorentino said Bartoletti died in a Florence hospital Sunday after a long illness.
In a career that saw Bartoletti conduct into his 80s, he served as the first music director of Chicago's Lyric Opera, starting as guest conductor there in 1956, when he was relatively unknown.
Conducting frequently in Italy, Bartoletti was artistic director at Maggio Musicale from 1986-1991. He also conducted in Buenos Aires and at Milan's La Scala.