The 35 year-old president, Daniel Noboa, faces a country where voters recently backed a referendum to restrict gold and copper mining.

The state-owned miner said it has reached a production 'turning point'.

"The downgrade of Codelco's ratings is a result of lowering its standalone credit profile," it said.

Panama's top court will hear the legality of the contract awarded to First Quantum from Nov, 24.

Spot prices for the six key metals that dominate trading on the LME are all at a discount to futures.

The Yangshan copper premium, or the fee traders pay for imported cargoes over benchmark prices on the LME, extended to its highest level in a year.

Rajo Inca, which is more than 60% built, is set to formally kick off operations next year.