Lithium names fell in Monday's trading after Chile's constituent assembly, in charge of writing the country's new Constitution, approved an early-stage proposal that would open the door to nationalizing some of the world's biggest copper and lithium mines, Mining.com reports.

SQM started the day at a 52-week high but closed -7.8%; also LIT -5.1%, ALB -3.9%, LAC -3.9%, LTHM -2.3%; among copper stocks, FCX -5.9%, SCCO -3%.

The motion by the environmental committee, which met over the weekend for the first time, received 13 votes in favor with three against and three abstentions.

The proposal, which targets mostly large-scale mining of copper, lithium and gold, has not yet been approved by two-thirds of the full assembly to become part of Chile's new charter, which will be voted on in a national referendum later this year.

Chile is the world's top copper producer and host to the two biggest lithium miners, and is rewriting its Constitution to replace a market-centric document.

Lithium Americas said a week ago that it was considering a potential separation of its U.S. and Argentina operations.