SANTIAGO, July 14 (Reuters) - Chile's Candelaria copper mine, run by the Canadian firm Lundin Mining Corp, on Tuesday rejected claims by the mine supervisors´ union that it is planning to lay off workers, saying the claim relates to the offer of an early retirement package for older workers.

The supervisors' union said on Monday the miner would cut 7% of its workforce in a belt-tightening exercise at a time when the mining industry is feeling the pinch from constraints placed on their operations aimed at limiting the spread of the virus.

Candelaria said the measure was part of an "optimization program" to ensure the sustainability of its operation in Chile's northern Atacama region.

"The program will be offered to all workers 55 years of age and older. The company estimates that around 100 workers will participate ... which represents between 5-7% of its staff," the company said in a statement sent to Reuters.

Copper production out of Chile has not yet been significantly impacted since the coronavirus outbreak started in March. In recent weeks however, there has been a surge of cases in the economically-critical industry, which has prompted operators to alter shift patterns and suspend smelters and construction projects.

Candelaria produced 111,400 tonnes of copper - just under 2% of Chile's total - last year.

Last week, global miner BHP Group Ltd offered workers at its Escondida copper mine in Chile, the world’s largest, the option for early retirement, drawing criticism for the union which rejected it as a scheme to oust the old and sick. (Reporting by Fabian Cambero, writing by Aislinn Laing Editing by Marguerita Choy)