First Quantum Minerals must make a plan to halt work at its copper mine in Panama then go ahead with the scheme within two days of approval, the Central American country said after it and the Canadian company had failed to agree on boosting taxes from the project.
The company has ten days to present the plan for the Cobre Panama mine, which the government has said accounts for 3.5% of gross domestic product, according to a resolution of the Commerce and Industry Ministry published in Panama's official gazette.
First Quantum can appeal against the ministry's order within five days, however.
A spokesperson for First Quantum did not immediately respond to a request for comment about the ministry's order.
Panamanian authorities reached the decision after both parties missed a deadline last week to finalise a deal that would have increased annual payments to the government to at least $375-million.
First Quantum says the mine is the largest private investment in Panama.