(Adds reaction from the company)
LIMA, April 8 (Reuters) - Copper output from Freeport McMoRan Inc's Cerro Verde mine in Peru, one of the country's biggest, was partially affected during a 48-hour strike that started early on Friday, the labor union said.
Workers are protesting what they describe as the diminution of their profit-sharing bonus this year. The union announced plans for the work stoppage last week.
Nearly all of the mine's 1,600 unionized workers took part in the strike, said union leader Zenon Mujica, who added "it has partially affected production."
The mine's management said in an email that it was complying with its labor agreement and declined further comment.
Cerro Verde, which is 53.6 percent-owned by Freeport, produced 41,873 tonnes of copper in February, up 180 percent from the same month in 2015 as the mine expanded operations.
Sumitomo Metal Mining Co Ltd controls 21 percent of Cerro Verde, and Peruvian miner Buenaventura owns 19.6 percent. (Reporting by Ursula Scollo; editing by Richard Chang, G Crosse)