Ehrlich died Sunday at his home in Riehen, a suburb of Basel, according to the family notice in Swiss newspapers.
The Berlin-born Ehrlich studied at the Higher Institute for Jewish Studies, Rabbi Leo Baeck's rabbinical seminary, until the Nazis closed it in 1942.
The Nazis made him perform forced labor until he was able to find shelter with a Berlin couple and was smuggled the following year into Switzerland.
He obtained his doctorate at Basel and later taught at universities in Switzerland and Germany. From 1961 to 1994 he was European director of the Independent Order of B'nai B'rith, founded in New York in 1843.
At the Second Vatican Council in 1965 he was the adviser to German Cardinal Augustin Bea in preparing "Nostra Aetate," a key document on Roman Catholic-Jewish relations.
Rabbi Walter Homolka, rector of Abraham Geiger College in Potsdam, Germany, eulogized Ehrlich as being "the bridge to Jewish heritage before the Holocaust" and an important liberal thinker.
Ehrlich was the author of several books on Judaism and was credited by the Free University of Berlin with "influencing generations of scientists."
Ehrlich is survived by his wife and a daughter. The funeral service is to be held on Thursday at the Liberal Jewish Community "Or Chadasch" in Zurich.