The economic development committee of Bolivia's lower house of congress has approved a bill to nationalize mines that will now move to the senate for consideration, the committee said in a statement.
One of the bill's most important points would nullify JV contracts and the rental of mines owned by Bolivia's state miner Comibol, except in the case of cooperative miners, the committee said.
Once the law goes into effect, contracts at mining operations would have to be renegotiated within 180 days and later presented to congress for approval.
The bill will also establish regulations for cooperative miners.
"It's important to consider the point of view of fellow cooperative workers... so they realize that none of the points are detrimental to cooperative miners," committee president José Pimentel was quoted as saying.
The lawmaker added that existing contracts are illegal because they have not been ratified by congress.
In April, President Evo Morales announced plans to revert to state control any mining concessions held by companies that do not comply with existing norms.
"Some companies are cheating us, they are stealing from us... we must recover those mines and return them to the state," Morales said at the time.
Initial measures already taken to revert assets to the state include granting state miner Comibol total control of the Huanuni tin deposit and the nationalization of the Vinto smelter that was in the hands of Swiss company Glencore Internacional, BNamericas previously reported.
Bolivia's mining cooperatives federation Fencomin declared a state of emergency for its group and is preparing to mobilize in opposition to the bill, local press said.
They also question the government's proposal to raise mining taxes and to divert a portion of it to a state fund created to develop mining activity, the report said.
Earlier this month the government said it planned to submit a bill to congress that would increase profit tax payments in the mining sector to up to 37.5% from the current 25%.
The situation means that over 20,000 cooperative miners from Potosí department are prepared to mobilize alongside their peers from other producing departments to demand a response from authorities, the report said.