Peru’s mining industry is warning that a bill moving through Congress to halve the time to hold unused concessions would end up discouraging investment and favoring informal operators.

“It’s a blow to formal mining that could wipe out $60-billion in investments,” Gonzalo Quijandría, vice-president of mining and energy society SNMPE, told Canal N.

The proposal, which passed committee this week and is headed for a floor debate, would cut to 15 years from 30 the period companies have to explore before a concession expires.

Industry groups say it can take decades to discover and develop a deposit, while small-scale miners argue that large companies hoard scarce mineral rights instead of developing them. In Peru, that tension is heightened as global firms increasingly compete with informal operators for control of mineral-rich areas.

Peru — the world’s third-largest copper producer and a major supplier of gold, silver and zinc — grants concessions that allow companies to explore vast areas for extended periods. But the rise of illegal mining and years of project delays have led some lawmakers to push for shorter concessions that could be developed more quickly by smaller operators.

If enacted, the bill could spur an “invasion of concessions,” SNMPE executive director Ángela Grossheim told RPP.

The issue is emerging in the run-up to Peru’s general election on April 12. Conservative front-runner Rafael López Aliaga has pledged to revoke exploration permits for idle projects and redistribute them.