Mexican federal officials say a mining conglomerate will set up a $151 million trust to pay for damage caused when one of its mines spilled acid-laced copper sulfate and heavy metals into two rivers in northern Mexico.

Economy Secretary Ildefonso Guajardo said Thursday that Grupo Mexico agreed to create the trust. He says authorities are still trying to determine the amount the company will have to pay to repair the damage in Sonora state.

Guajardo says those affected will have to file complaints that will be decided on by a committee of experts and government officials before getting money from the trust.

The company blamed heavy rains for the overflow of containment ponds on Aug. 7. Officials say lax supervision at the mine appeared to have caused the accident.