By Diego Ore

CARACAS (Reuters) - Venezuela's socialist government on Tuesday announced a nationwide electricity rationing plan to tackle a surge in demand caused by rising temperatures in recent weeks.

The measures include cutting the workday for public officials to six hours, asking private companies to boost energy efficiency and inspecting malls and factories to ensure they meet reduced power consumption targets.

"Within a week, power demand has risen 1,500 megawatts," Electricity Minister Jesse Chacon said on state TV. With demand at 18,000 megawatts, he said, "the system begins to have stability problems."

Peak temperatures in recent weeks have risen to 34 degrees Celsius (93 degrees Fahrenheit) in Caracas, the capital, and have hit 37 degrees Celsius (99 degrees Fahrenheit) in the sweltering western city of Maracaibo.

The country's average annual consumption per household is 5,878 kilowatt-hours, double the average of the region due largely to sizable subsidies that allow consumers to run air conditioners with little regard to cost.

Power outages are common in the oil-rich country, which depends on hydroelectric dams for 64 percent of its generation.

President Nicolas Maduro's critics say the problems are the result of under-investment in the sector since late socialist leader Hugo Chavez nationalized much of the electrical system in 2007.

A drought in 2010 forced Chavez to institute a broad rationing plan that was widely unpopular, helping push his popularity to the lowest of his 14-year-rule and crippling the country's state-run mining industries.

On Monday, local media reported blackouts in at least 10 of the country's 24 states, pressuring an economy struggling with recession, high inflation and shortages of basic goods.

Maduro has blamed some blackouts on "sabotage."

(Writing by Diego Ore; Editing by Brian Ellsworth and Dan Grebler)