Venezuela intensified its nationalization fight with foreign companies on Monday, vowing to impose a takeover of oil majors' operations and grab all of a U.S. utility's stake in the country's largest private power company.

The OPEC nation's energy minister revealed that President Hugo Chavez's announcement last week of a new nationalization drive meant Venezuela was ending months-long talks with some of the world's biggest companies over planned oil takeovers.

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The minister, Rafael Ramirez, also said Chavez's plan to nationalize the electricity sector included taking U.S.-based AES Corp.'s (AES) 87-percent stake in the sector's flagship company.

The takeover of Electricidad de Caracas could also come much sooner than many investors expected, with Ramirez saying at a news conference it was a "reasonable" goal to complete the move by the end of June.

AES did not immediately respond to a request for comment on the issue.

Since a landslide re-election last month, Chavez has consolidated power over the media and political parties and his minister's remarks underscore the harder line he intends to take against foreign companies in his new six-year term.

"We gave them enough time but now negotiations are impossible," Ramirez said of talks over the state taking a majority stake in multibillion dollar projects in the Orinoco belt.

Instead the government would impose the takeover by passing a new law, he said, adding, "once the respective law has been issued ... we can (begin) a discussion with the transnational companies."

Chavez is armed with a strong mandate but he is taking on businesses with bigger earnings than most nations — including Exxon Mobil (XOM), the world's largest company — for control over what he calls the earth's hugest oil reserve.

The anti-U.S. former soldier who says Cuban President Fidel Castro is his mentor has used record oil revenues to finance a self-described socialist revolution for the poor majority.

Now he wants more of that income and the battle is over four projects worth an estimated $33 billion that would give Chavez domain over a reserve believed to hold up to 235 billion barrels of tar-like oil.

Six companies — Chevron (CVX) , Conoco (COP), Exxon Mobil, BP (BP), Norway's Statoil and France's Total — have invested around $20 billion for 60 percent of the joint ventures, with state oil firm PDVSA already holding the rest.

The companies have declined to comment on the nationalization offensive.

Ramirez also said the government wanted to merge the refineries in the four separate ventures into one downstream operation that upgrades the Orinoco crude.

POWER GRAB

For years, Chavez has moved against private companies in the energy sector. With solid profits in an era of generally high oil prices the companies have offered some resistance but eventually agreed to changes.

Still, energy analysts say the majors have balked at the Orinoco takeover because of the huge investments they made there.

In the electricity sector, Ramirez drew a distinction between smaller investors and AES, pledging to allow minority shareholders to keep a stake in Electricidad even though the U.S. utility will lose all of its holding.

On the Caracas stock exchange, the share price of Electricidad, which serves the capital, fell 6 percent.

Ramirez pledged to protect workers' interests when the state runs the company, in contrast, he said, with AES's management-style.

"When AES bought it ... the first thing the group did was reduce the payroll," he said.

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