LIMA, May 5 (Reuters) - A man protesting Southern Copper Corp's $1.4 billion Tia Maria project in Peru was killed in clashes with police on Tuesday, the second death in two weeks as government talks with opponents remain thwarted.
Interior Minister Jose Luis Perez said authorities were investigating how the protester was killed and two others wounded in Peru's southern region of Arequipa.
Tia Maria has the potential to add 120,000 tonnes of copper to Nasdaq-listed Southern Copper's annual supply, but the project has been stalled since three people died in similar rallies in 2011. Opponents say they fear the project will pollute surrounding agricultural valleys.
Helar Valencia, one of four local mayors calling for Tia Maria's cancellation, said the death of another protester further eroded trust in national authorities.
"This is going to anger people even more," Valencia said. "If before only some were against Tia Maria, now I think it's the whole valley."
Perez, who said he had ordered police not to use lethal weapons, replaced local law enforcement chiefs after another protester died from a bullet wound April 22.
Southern Copper said last week that the protests might delay the project's 2017 start date and that progress hinged on talks between opponents and the government of President Ollanta Humala, who supports Tia Maria.
Valencia said talks broke down more than two weeks ago and had not resumed since.
Construction on Tia Maria was poised to start when the protests broke out more than 40 days ago.
Southern Copper, controlled by Grupo Mexico, received an environmental permit for Tia Maria last year after it agreed to build a desalinization plant to ease pressure on local water supplies.
Conflicts over mining projects in Peru, the world's third-biggest copper producer, have held up billions in investment and left several protesters dead in recent years.
Reporting By Mitra Taj; Editing by Ted Botha