Officials at Rio Tinto are deciding their interest in one of the world’s biggest copper mines following passage of new mining legislation in Papua New Guinea, with the No. 2 miner possibly pulling out. An insurgency ceased operations at the company’s Panguna project in 1989; the asset produced some 3 million copper tons and 9.3 million oz gold over 17 years.

The interim law allows for conversion of Bougainville Copper Ltd.’s current lease into an exploration lease, which can, in turn, become a mining lease if approved by the island’s provincial government. Rio Tinto, which declined comment, according to Reuters, owns a 53.83% stake in the company; the government and private shareholders own the rest.

Bougainville Copper has been in talks with Papua New Guinea, and Bougainville officials over whether to return. Chairman Peter Taylor told Reuters it would then need to gain a feasibility study, a mining lease, order equipment, rebuild some roads and an export port; Papua New Guinea was under Australian rule when operations began in 1972.