Chilean environmental regulators approved a proposed US$4.35 billion expansion of Antofagasta Plc's Centinela copper mine in northern Chile, Reuters reported Dec. 12.

The two-stage expansion will extend the life of the mine to 2056 and will double its copper output to more than 400,000 tonnes per year.

Antofagasta CEO Iván Arriagada said the company will complete engineering studies in the coming months.

The company expects to submit the proposal to its board in 2018 once studies are completed, with final authorization being subject to securing the required investment.