MOSCOW (AP) - Lawmakers voted Wednesday to give Russia's natural-gas and oil pipeline monopolies the right to set up armed security units to protect the country's energy infrastructure.

One lawmaker said the move could lead to "a multitude of corporate armies."

Instead of hiring private security firms, state-controlled gas giant OAO Gazprom and oil pipeline monopoly OAO Transneft would be able to directly arm and recruit their own security forces, under a bill passed by the lower parliament house, the State Duma.

To become law it must be approved by the upper house, the Federation Council, and signed by President Vladimir Putin.

Gazprom, the world's biggest gas producer, controls Russia's main gas pipelines and is the only company allowed to handle exports. Transneft, which is also state-run, has the monopoly on oil pipelines.

Lawmaker Gennady Gudkov, who opposed the bill, warned that it could open a "Pandora's Box."

State-controlled giants like savings bank Sberbank, electricity utility UES and the railways monopoly could all seek the same right, he said.

"As a result there will soon be a multitude of corporate armies in the country," Gudkov said.