Residents in two Romanian regions will vote next month in referendums on gold mine and shale gas projects as the government ponders whether to approve the plans.

The December 9 referendums held alongside general elections are not binding but the government may invoke them in its future decisions, analysts said.

Around 70,000 residents of Alba county in central Romania will be asked to say if they agree to the resumption of mining in the region and at the Rosia Montana gold mine.

"It is important to have a referendum on this issue because we need an answer from the central authorities on the future of mining," the head of the local council, Ion Dumitrel, told AFP.

A Canadian firm, Gabriel Resources, plans to extract some 300 tonnes of gold and 1,600 tonnes of silver over 16 years in the village of Rosia Montana.

The company is still waiting for a key permit from the government.

Environmentalists, archaeologists and historians oppose the mine, which will use cyanide in the leaching process, and partially destroy four mountains and Roman-era mining galleries.

The inhabitants of the south-eastern city of Mangalia on the Black Sea coast will be asked the more pointed question of whether agree to ground water and tourism in the region being damaged by shale gas drilling.

American oil giant Chevron, which has four concessions in southeastern and eastern Romania, was hoping to drill the first shale gas exploration well in the second half of 2012.

But the centre-left government in power since May has imposed a moratorium of shale gas until December.

The drilling technique, hydraulic fracturing or "fracking", uses high pressure injections of water, sand and chemicals to crack open rock and release oil and gas trapped inside.

The technique poses serious environment and health risks and has been banned by countries such as France and Bulgaria.