A union that groups together around 200 Anglo supervisors in Chile began a strike on Friday after rejecting the company's proposal for a new collective contract.

"There has been no impact to production. We are producing normally at all our projects," said a spokesman for the company in Santiago.

Those on strike represent about 18 percent of the company's supervisors in Chile, he added.

Anglo expects to produce between 725,000 and 740,000 tonnes of copper in 2014.

(Reporting by Fabian Cambero; Writing by Rosalba O'Brien; Editing by Chris Reese)