Vatican Radio reports that he died on Saturday due to a long illness.
Following the death of Cardinal Dionigi Tettamanzi, Pope Francis has sent a telegram of condolence to Archbishop Mario Delpini, Archbishop-elect of Milan.
He said: "I think with affection and remember with gratitude the intense cultural and pastoral work accomplished by this praiseworthy brother, who in his fruitful life has borne witness with joy to the Gospel, and docilely served the Church."
During his long tenure as Catholic leader, Cardinal Tettamanzi's was first ordained a priest of the Archdiocese of Milan in 1957, then a Bishop of Ancona-Osimo, a secretary of the Italian Bishops' Conference, an Archbishop of Genoa, an Archbishop of Ambrosian Church, and most recently Apostolic Administrator of Vigevano.
He earned his Doctorate in Sacred Theology from the Pontifical Gregorian University. Pope St. John Paul II named him Cardinal on 21st February 1998.
Francis added that Cardinal Tettamanzi "always distinguished himself as a caring pastor, totally dedicated to the needs and well-being" of his priests and people. He also noted the Cardinal's expertise in the fields of family, marriage, and bioethics.