The company said there were some errors in the information that led Chilean regulators to draw up the charges but it did not elaborate on the source or specifics of what information it believes to be erroneous.

Antofagasta said it has been working alongside the relevant authorities for an extended period of time to ensure compliance at the mine.

"Although we have not been informed (of the charges) in an official manner, in many of the areas mentioned by the SMA (environmental regulator) press release there has been work ongoing for months, even years, to search alongside official bodies for ways to guarantee total compliance with environmental regulations," Francisco Veloso, the mine's chairman, said in a statement.

The punishment for the alleged infractions could carry a fine of up to $23.8 million, or even the temporary or permanent closure of the mine, though the latter options are unlikely. [nL1N1CJ2GF]

While the company did not give a specific date for presenting its defence, its legal deadline is 15 days after its official notification.

Antofagasta's London-listed shares closed down 3.6 percent on Friday.

The Los Pelambres mine, located in Chile's north-central Coquimbo region, produced 375,800 tonnes of copper in 2015.

(Reporting by Gram Slattery; Editing by Will Dunham and Diane Craft)