* Sanctions against Caracas companies planned for Monday

* Chavez says opposition personalizing power crisis

(Adds opinion poll)

CARACAS, March 21 (Reuters) - Venezuela announced on Sunday 24-hour power cutoffs for dozens of companies that have failed to reduce usage in the first punitive measures of a nationwide drive to save energy amid an electricity crisis.

Restaurants, liquor stores, hotels, gyms, car dealerships and a yacht club were on the list of 80 firms in the capital Caracas due to have their power cut on Monday for failing to bring consumption down 20 percent, the state utility said.

The local unit of Japanese firm Sony Corp 6758.T will also be among those sanctioned.

President Hugo Chavez’s government has introduced rationing, and demanded power cuts across the South American OPEC member, to cope with an electricity shortage that is jeopardizing Venezuela’s ability to pull out of a recession.

Drought has hit the hydroelectric sector that produces more than 70 percent of Venezuela’s electricity. Rains are due in weeks, with some showers already starting in recent days, and the government says fears of a “collapse” are unfounded.

The opposition, preparing for a September legislative election being cast as a referendum on Chavez and a curtain-raiser for the 2012 presidential vote, says he is to blame for incompetent management of the power sector.

Polls show Chavez’s traditionally high popularity, especially among the poor, is suffering from the power crisis.

The latest survey, by Alfredo Keller and Associates, which is perceived by many to favor the opposition, gave Chavez a 43 percent approval rating, saying it was his lowest since 2003.

Only 26 percent thought the government was taking the right measures in the electricity campaign, according to the poll, made public on Sunday by private TV network Globovision.

THERMOELECTRIC HOPES

“This (opposition) campaign has, of course, one single aim: declare Hugo Chavez guilty of everything, even the drought,” the leftist leader wrote in a regular Sunday column he pens.

“Indeed, I would love to have the powers I’m accused of by the opposition to defeat this situation which not only hurts Venezuela but the whole world as a result of the destructive voracity of the capitalist system.”

Chavez said Venezuela’s planned addition of nearly 6 gigawatts of thermoelectric energy this year, taking national capacity to around 30 gigawatts, would help solve the crisis.

In a carrot-and-stick approach to businesses, state power firm Electricidad de Caracas also published a list of 81 companies that had surpassed the 20 percent reduction target.

If the companies to be sanctioned on Monday do not improve their energy-saving performance in the future, they face a three-day cutoff then possible indefinite power suspension.

Most attention in the energy crisis has centered on the Guri reservoir, which normally supplies more than half of Venezuela’s electricity but has been drying up at the rate of about 6 inches (15 cm) a day in recent months.

Media have been showing pictures daily of lowering waters, and counting down to a danger-level of about 240 yards (metres) -- from 252 now -- when output would drop drastically.

But Environment Minister Alejandro Hitcher said imminent rains, energy-saving measures, and extra thermo-electric capacity would prevent the disaster some were predicting.

“Guri is not going to collapse,” he said. “To the disappointment of those generating this campaign, ignoring the environmental disaster we are suffering and subjecting the population to a sort of state of terror.”