Utilize the input text as a context reference, choose the right relationship between Codelco and copper from the options. Options: product/material produced, manufacturer, distributed by, industry, position held, original broadcaster, owned by, founded by, distribution format, headquarters location, stock exchange, currency, parent organization, chief executive officer, director/manager, owner of, operator, member of, employer, chairperson, platform, subsidiary, legal form, publisher, developer, brand, business division, location of formation, creator.

SANTIAGO, Sept 28 The world's No.1 copper producer Codelco said on Monday that it was reducing the number of executives on its payroll by 15.6 percent, as the Chilean state-owned miner cuts costs in the face of tumbling prices for the industrial metal.

Answer: product_or_material_produced