(Adds comment from union leader)

LIMA, March 31 (Reuters) - Workers at Freeport McMoRan Inc's Cerro Verde mine in Peru plan to go on a 48-hour strike April 8 to protest what they describe as the near disappearance of their profit-sharing bonus this year, the union said Thursday.

Freeport has a 53.56 percent stake in the mine, one of Peru's biggest with 32,000 tonnes of reported copper output in January. Sumitomo Metal Mining Company Ltd controls 21 percent and Peruvian miner Buenaventura owns 19.58 percent.

Each worker is scheduled to receive an average bonus of 483 soles ($146) this year based on 2015 profits, down from about 30,000 soles ($9,090) the year prior, said union leader Zenon Mujica.

Copper lost a quarter of its value in 2015, the red metal's biggest slump since 2008.

Representatives of Cerro Verde could not immediately be reached for comment outside regular working hours.

($1-3.3 soles) (Reporting by Teresa Cespedes; Editing by Sandra Maler)