FILE PHOTO: A drone view shows the entrance to Codelco's El Teniente copper mining complex, in Maitenes, Chile August 1, 2025. REUTERS/Pablo Sanhueza/File Photo

By Fabian Cambero

SANTIAGO (Reuters) -Chile's mining regulator Sernageomin is raising its requirements for copper giant Codelco to restart areas of its flagship El Teniente mine after a deadly collapse, according to a document seen by Reuters on Monday.

The document said Sernageomin will require a follow-up and monitoring plan for the stability and safety of mining operations across all underground deposits of Codelco's El Teniente mine that have yet to be re-opened.

Codelco immediately shuttered all sections of the vast mine, its most profitable, after the July 31 accident that killed six people.

Since then it has opened eight of 12 sectors at the mine, which contains several thousand kilometers of underground tunnels in the Andes mountains near Santiago.

Codelco said on Monday it is working to gradually re-open the Andes Norte and Diamante sectors, after approvals from Sernageomin and the labor inspector's office, but said its Recursos Norte and Andesita units remain closed.

Codelco did not immediately respond to a request for comment about the new requirements outlined by Sernageomin.

Sernageomin had already requested a series of reports from Codelco before signing off on re-opening units of the mine, including a control measures report to prevent new incidents.

Codelco, the world's largest copper producer, cut its copper forecast for this year due to the impact of the accident.

The collapse mainly affected the new Andesita development, but Andes Norte, which had begun extraction, and Diamante were also halted as part of the investigation.

(Reporting by Fabian Cambero; Writing by Alexander Villegas; Editing by Kylie Madry)