Slovakia's prime minister warned foreign energy companies their stakes in the country's utilities could be seized if their prices were too high for Slovak consumers.
Premier Robert Fico said the state could retake companies privatized after Slovakia gained independence in 1993 with the breakup of former Soviet satellite Czechoslovakia.
"This is not a false threat, this is a real thing," Fico said, after meeting with his Czech counterpart, Mirek Topolanek, in Prague.
Fico said the Slovak constitution allowed for the expropriation of private property if the interests of the Slovak people were threatened.
Retail energy prices are on par with those in the neighboring Czech Republic, at 2.84 koruna (US$0.171) per kwh, but are rising slowly, Atlantik FT analyst Petr Novak said.
Italian company Enel has a 66-percent stake in Slovenske elektrarne, the country's electric power utility. Germany's E.ON Ruhrgas and France's Gaz de France own 49 percent of the Slovak Gas Holding.
"Any price (of energy) in Slovakia must correspond with the purchasing power of the Slovak people," Fico said. "We are still far from the average standard of living in the EU."
Slovakia joined the European Union in 2004 and plans to adopt the euro common currency on Jan. 1.