Unions at Antofagasta's Centinela Copper Mine Call Strike Vote as Labour Talks Reach Impasse

Two unions representing workers at Antofagasta Minerals' Centinela copper mine in Chile have called a strike vote after collective bargaining negotiations with the company reached an impasse.​

The Trabajadores de Minera Esperanza and Trabajadores Distrito Centinela unions said they received the company's latest offer on September 23 as part of their joint collective bargaining process. After reviewing the proposal, the unions called on their members to vote on whether to strike, with voting scheduled to take place between September 26 and September 28.​

The unions said the latest proposal failed to resolve their concerns over differences in benefits and remuneration between workers performing similar functions. The two organizations have been conducting a joint bargaining process and have called for greater alignment in employment conditions.​

However, a strike has not yet begun and operations at Centinela have not been reported as disrupted. Under Chilean labour procedures, if workers vote to reject the company's offer, the parties must still undergo a mandatory five-day government mediation period before a legal strike can begin. The mediation period can be extended by another five days if both sides agree.​

Antofagasta Minerals declined to comment on the ongoing collective bargaining negotiations. The company had previously disclosed that two collective bargaining processes involving workers' unions at Centinela were scheduled for the second half of 2026.​

The strike vote introduces a near-term supply risk at Centinela, although there has been no reported impact on copper production at this stage. The immediate focus will be on the September 26–28 vote and, if workers approve strike action, whether the subsequent mandatory mediation process results in an agreement. Any escalation into an actual work stoppage could increase supply-side uncertainty in Chile's copper sector, while an agreement during mediation would limit the operational impact.