Jan 18 (Reuters) - Workers at the main units of Southern Copper in Peru plan to vote late next Wednesday on whether to hold another strike, union leader Ricardo Juarez said on Friday.
Union leaders are not satisfied with what Southern Copper has offered after two weeks of negotiations over new contract terms and will discuss options with workers early next week, he said.
Workers, who held a two-day strike at the end of December, are asking for a 15 percent wage increase as well as better safety conditions and health benefits, Juarez said.
A Southern Copper official in Peru declined immediate comment.
Some 2,500 people work at Southern Copper's units in Cuajone, Toquepala and Ilo.
Southern Copper, an affiliate of Grupo Mexico, produced about 24 percent of Peru's copper production in 2011.
Peru is the world's No. 2 copper exporter after Chile.