Chilean copper miner Antofagasta has said restrictions to access to repair a leak in the concentrate pipeline at the Los Pelambres processing plant have been eased and it should resume operations by the end of this month.

Repairs to the pipeline have commenced, however, some access restrictions remain that will prolong the time required to complete the scheduled work, said the firm.

"Engagement with the authorities and communities continues, with the aim of removing these remaining road access restrictions. Given the outstanding repair work and the testing required for a safe restart, which includes working with the relevant local regulator, it is expected that the operation of the pipeline will be resumed by the end of June".

During the shutdown the processing plant has been operating at lower rates of throughput, with concentrates being stockpiled at the plant. These will be transferred to the port between July and October using the spare capacity of the pipeline.

Full year copper production for the Group is expected to be at the bottom end of the original 660 - 690,000 tonnes guidance range. A further update on the impact of the leak will be provided in the Company's 2Q Production Report on 20 July.

Los Pelambres on May 31 detected a leak in the underground pipeline that transports concentrate from the concentrator plant to the port at Los Vilos. A replacement pipeline that is currently being designed and permitted, which is expected to be in operation by 2025.

The full year impact on production will depend on the duration of the shutdown.