Venezuela's minister of basic industries and mining (Mibam), Rodolfo Sanz, said the country's government is looking at withdrawing the concessions for mining areas in Bolívar state's El Callao zone.

"We have taken steps to prompt the expiration of concessions in the zone that can perfectly well be reassigned to small-scale miners in the zone," Sanz was quoted as saying by local press.

The official said the measure came under consideration following the transfer of some mining concessions held by the company Promotora de Guayana (PMG), which was previously owned by South African miner Gold Fields (NYSE: GFI) and acquired by Canada's Rusoro Mining (TSX-V: RML) in December.

The transfer allegedly left nearly 600 workers unemployed, the reports said.

Sanz also said the government has approved a payment of 15mn bolívares (US$7mn) to develop seven projects presented by workers in the El Callao zone.

He added that his office is assessing how PMG came to possess its mining concession as state heavy industry holding company CVG controlled 30% of the mining rights.

"We are discussing whether it was a legal procedure or not. That is under review by Mibam's legal council," Sanz said.

Venezuela's President Hugo Chávez has banned concession transfers in an effort to guarantee miner protection, according to Sanz.

This week Mibam also warned Rusoro, which controls the Choco 10 gold mine in El Callao, that it must fulfill commitments the previous owner made to employees and is required to pay compensation that was promised to the workers.