Renato Ruggiero, who has died aged 83, was born in Naples in 1930 and studied law at Naples University, graduating in 1953.
He entered the Italian diplomatic service in 1955 and, after an initial posting in Brazil, was sent to the Soviet Union in 1959, where he followed the developments that led from the confrontation over Berlin to peaceful coexistence and the normalisation of relations between the Soviet Union and Italy. In 1962, he was posted to Washington, from where he followed the Cuban crisis.
He returned to Rome at the end of 1964 as head of the political affairs secretariat and in 1969 embarked on the second phase of his diplomatic career, related to Europe. In July 1970, he was appointed chef de cabinet of the president of the European Commission, Franco Malfatti.
He followed in particular the negotiations on the accession of the United Kingdom, Ireland and Denmark and the developments that led to the first definition of the European Monetary Union and the launching of the European Union project (Paris, European Summit in 1972).
After a brief period as political adviser to the new president of the commission, Sicco Mansholt, he was appointed director general for regional policy. Together with European commissioner George Thompson, he negotiated and created the European Regional Development Fund.
In 1977, he became the spokesman for the president of the commission, Roy Jenkins, and helped to launch the concept of the European monetary system and the subsequent negotiations.
In 1978, he returned to Rome as co-ordinator of community affairs at the ministry of foreign affairs. In this post he helped to define and negotiate Italian participation in the European monetary system.
In 1987, he was appointed Italy's minister for foreign trade and immediately became involved in trade and currency liberalisation, a task he completed before leaving the government in 1991. In 1995 he became first director general of the World Trade Organisation, a post he occupied until 1999.
In 2001 he was briefly minister for foreign affairs in the second Berlusconi government but left over clashes with the separatist Lega Nord. He later acted as adviser to Romano Prodi in his second government.
The current WTO director general, Pascal Lamy, said: "I knew [Rugierro] to be an internationalist who believed that the path to a better future lay in strong institutions that are dedicated to building bridges between people. In Italy, in Europe and on the world stage, Renato Ruggiero dedicated his life to bringing people together."