COPENHAGEN, Denmark — Norway’s minority center-left government and two large opposition parties made a deal Tuesday to open the Arctic Ocean to seabed mineral exploration despite warnings by environmental groups that it would threaten the biodiversity of the vulnerable ecosystems in the area.

Norway said in June that it wanted to open parts of the Norwegian continental shelf for commercial deep sea mining in line with the country’s strategy to seek new economic opportunities and reduce its reliance on oil and gas.

The head of Greenpeace Norw=ay, Frode Pleym, said the decision was “a disaster for the sea” and the mining would take place in “our last wilderness.”