TORONTO, May 25 (Reuters) - Freeport McMoRan Inc, the world's largest publicly traded copper miner, said a "large number" of the approximately 4,000 workers at its giant Grasberg mine in Indonesia who failed to report for work have been deemed to have resigned.
An estimated 9,000 workers have extended their strike for a second month at Grasberg, the world's second-largest copper mine, in an ongoing dispute over employment terms and layoffs, the union said on May 20.
In a May 15 memo obtained by Reuters, Freeport said that the strike is illegal and "voluntary resignation is the consequence" for workers who ignored demands to return to work and were absent for five consecutive days.
"Mining and milling rates have been impacted," at Grasberg, said Freeport spokesman Eric Kinneberg. "(Freeport) is taking steps to mitigate the impact by re-allocating resources and training additional workers, and from supplementing its mill throughput with available stockpiles."
The majority of Freeport's approximate 30,000-member workforce are working "productively and safely and operations continue to improve," he added. (Reporting by Susan Taylor)