Most employees at Freeport-McMoRan’s Chino Mine will be placed on an unpaid furlough for “up to 30 days” beginning Sunday, the managers of Chino and Tyrone mines announced in a joint letter to community leaders Friday afternoon.

The letter, signed by Chino Operation General Manager Chad Fretz and Tyrone Operation General Manager Erich Bower, said that furloughed employees would technically remain employed with the company even though they were not being paid, and would also be eligible for benefits during that time. The furloughs come in the wake of a global economic slowdown and a slump in copper prices, thanks to the COVID-19 pandemic, and aren’t likely to be the mining company’s only response to the crisis.

“While there remains some uncertainty on the total impact to our workforce, it is clear we will be required to lay off a large number of employees,” Fretz and Bower wrote in the letter, noting that employees who continue to work during the furlough won’t necessarily be exempt from later layoffs. “Those impacted could include employees on an unpaid furlough and/or those who remain working during this time.”

According to the letter, no additional changes are expected at the company’s Tyrone Mine, where workers will not be furloughed.

“At our Tyrone operation, we will not see any significant changes based on these revised operating plans,” Fretz and Bower wrote. “However, we will continue cost-cutting and efficiency measures already in progress.”

Despite the furlough, limited operations at Chino are expected to be restarted Sunday, including the mine’s Hydromet operation. The mine has been largely closed since Saturday, April 11, when the decision was made to suspend work after an outbreak of COVID-19 among workers in the mine’s truck shop.

”Given the fluidity of the situation, we cannot predict the course or extent of this pandemic and its economic impact or the exact length of the furlough, but we will continue to provide you with updates as we learn more,” the letter said. “While we normally would provide more notice, we are giving as much notice as possible given the unforeseen business circumstances related to COVID-19.”

Freeport-McMoRan employs about 1,500 people at its New Mexico operations, according to a 2018 company report.

Calls to Linda Hayes, Phoenix-based vice president of communications for Freeport-McMoRan, seeking additional comment on the announcement were not immediately returned Friday afternoon.

This is a developing news story, and it will be updated with additional information as it becomes available.