The Convention on the OECD was signed in Paris on 14 December 1960 when the Organisation for European Economic Co-operation (OEEC), formed in 1948 to administer aid under the Marshall Plan for the reconstruction of Europe after World War II, was reconstituted as the Organisation for Economic Co-operation and Development, "in order to strengthen the tradition of co-operation and apply it to new tasks and broader objectives".

The Convention came into force on 30 September 1961. 

Supplementary protocols

The Convention is complemented by:

• Supplementary Protocol No. 1 which concerns participation by the European Community in the work of the Organisation;
   
• Supplementary Protocol No. 2 to the Convention on the OECD which sets out the Privileges and Immunities enjoyed by the Organisation, including those provided for in Supplementary Protocol No. 1 to the Convention for European Economic Co-operation on the Legal Capacity, Privileges and Immunities of the Organisation (16 April 1948);
   
• Bilateral Privileges and Immunities Agreements with the countries that have become Members since 1960. 

Ratification

Thirty six countries are now party to the Convention, the twenty "founder" Members and a further sixteen who have subsequently become Members. 

Declarations by certain Member countries

Some countries have made "Declarations" concerning principally the territorial application of the OECD Convention.

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