Prof. Bonell is Emeritus Professor of Comparative Law at the Law Faculty of the University of Rome I "La Sapienza" (since 1986). Professor Michael is a consultant at the International Institute for the Unification of Private Law (UNIDROIT), Rome (since 1978). He is the Chairman of the Working Group for the preparation of the UNIDROIT Principles of International Commercial Contracts (since 1981).
He was Member of the Italian delegation to the Diplomatic Conference for the adoption of the U.N. Convention on Contracts for the International Sale of Goods (Vienna 1980). He was a representative of Italy to the United Nations Commission on International Trade Law (UNCITRAL) (1980-2000).
He is the Editor in chief of the database "UNILEX - International Case Law & Bibliography on the UN Convention on Contracts for the International Sale of Goods and the UNIDROIT Principles of International Commercial Contracts".