UPDATE 1-Mexican miners strike at Gammon Gold mine on wages

(Updates company comment)

MEXICO CITY, April 29 (Reuters) - Mexico's mining union said on Wednesday 420 workers laid down tools at the El Cubo gold mine owned by Canada's Gammon Gold (GAM.TO) because of a dispute about working hours and wages.

The union is asking for an 8 percent salary increase plus 3 percent in benefits, and objects to the company imposing a 10-hour work day instead of the standard eight hours, it said in a statement.

"Operations are suspended until this problem is resolved," Luis Chavez, Gammon's director of Mexico operations, told Reuters.

The company produces 60,000 ounces of gold equivalent a year at the El Cubo mine.

In addition to the El Cubo mine in Guanajuato, the company operates the Ocampo mine in the northern state of Chihuahua and mined at total of 72,566 tons of underground ore in Mexico in 2008.

The national union has been at the forefront of a nearly two-year-long strike at the country's largest copper mine owned by Grupo Mexico (GMEXICOB.MX) and has staged walk-offs during annual contract renegotiations to press for higher salaries. (Reporting by Mica Rosenberg)