In 1962 joined the United Nations Secretariat in New York as an Associate Professional Officer P-2 in the Division of Public Administration, where he was responsible for the OPEX Program.

[1] In 1972 chosen by Maurice Strong for his team to run the United Nations Conference on the Human Environment (UNCHE) in Stockholm, where he was a liaison officer with the Western European and Others Group (WEOG).

In 1980 became UNEP Acting Director for Europe in Geneva, and in 1982 was appointed first Co-ordinator (D-2) of the Mediterranean Action Plan in Athens.

[2] During his tenure, the secretariat of the 1976 Barcelona Convention for the protection of the Mediterranean Sea against pollution grew from a few staff members to encompass four regional specialized offices in Malta, Split, Tunisia, and Sophia Antipolis (France), with a staff of fifty, entirely financed by the twenty-one Mediterranean coastal States.

Appointed Professor of Ecology and Environmental Diplomacy at the School of International and Diplomatic Sciences, University of Trieste, Gorizia campus for the maximum three-year period (1994–1997).