H. L. Davies, W. J. S. Howell, R. S. H. Fardon, R. J. Carter, and E. D. Bumstead
(in Porphyry copper deposits of the southwestern Pacific islands and Australia)
Economic Geology and the Bulletin of the Society of Economic Geologists (August 1978), 73(5):796-809

Abstract:
The Ok Tedi porphyry copper-gold deposit in western Papua New Guinea was discovered and tested by a subsidiary of Kennecott Copper Corporation in 1968-1971. Exploration lapsed in 1972-1975 while Kennecott and the government of Papua New Guinea sought agreement on terms which would apply to any future mining operation. Negotiations failed in March 1975. Over the following fifteen months, the government carried out further testing and in 1976 entered into an agreement with an international consortium of companies led by The Broken Hill Proprietary Company Limited of Australia for final feasibility investigations and studies.