Under de Seynes, the following organizations were established: United Nations Conference on Trade and Development (UNCTAD), United Nations Conference on Science and Technology (UNCSAT), United Nations Environment Programme (UNEP), United Nations Population Fund (UNFPA), United Nations Development Programme (UNDP), United Nations Industrial Development Organization (UNIDO), and the regional economic commissions. Under his stewardship, the United Nations initiated a series of Development Decades and a unified approach with the merger of the Technical Assistance Administration (TAA) and DESA. De Seynes left DESA in 1974 and became the Director of the United Nations Institute for Training and Research (UNITAR) Project on the Future.