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BERLIN (AP) — Chancellor Angela Merkel on Monday touted her government's new agreement that would grant nuclear power plants an average of 12 extra years of production as "revolution of the energy supply" for Germany — though it immediately drew criticism from opposition parties and environmental groups.

The agreement — which still needs parliamentary approval — is the latest sign of a renewed appetite for nuclear energy in Europe despite controversy over the subject since the 1986 Chernobyl disaster.

Merkel's government has cast the deal as a way to keep energy cheap in Germany by allowing it to use nuclear-powered and coal-fired plants as bridging technologies while developing and expanding renewable energies. The government will also garner more money through a new levy on utility companies.

The agreement effectively ends a plan put in place by a previous government in 2000 to shut down all of Germany's nuclear plants by 2021. The deal was popular among many still wary of atomic energy since the 1986 explosion and fire at the Soviet nuclear power plant that spread radiation over parts of Europe.

After the announcement, opposition parties immediately vowed to try and block the extension in the courts, claiming that the government caved to industry pressure.

Greenpeace suggested that Germany did not need the extension and that it could end up setting back the country's drive to expand its renewable energy supply.

"Only several large corporations would benefit form it with massively increased profits," spokesman Jan Beranek said. "The rest of society would badly loose."

The deal was also controversial even within Merkel's government, with disagreements among top ministers over how long the extensions should be. Merkel, several ministers and key leaders from her center-right coalition forged the compromise in a marathon negotiating session Sunday following months of public wrangling.

The decision puts Germany on track to securing the "most efficient and environmental friendly energy supply worldwide," Merkel told reporters in Berlin.

The agreement foresees that the country's 17 nuclear power plants will remain online for 12 more years on average beyond 2021, with older plants getting an extra eight years and more recent ones 14 additional years, the government said.

In return for the expected additional profits, utility companies will have to pay an annual fuel tax expected to be euro2.3 billion ($3 billion) starting next year, and will have to contribute to a special fund to boost renewable energies. The government did not specify how much the latter was meant to raise from the four nuclear power utilities — E.ON AG, RWE AG, EnBW AG and Germany's subsidiary of Sweden's Vattenfall Europe.

The Federation of German Industries welcomed the agreement as an important step for keeping energy prices low and securing the country's competitiveness, the organization's managing director Werner Schnappauf said.

But the main opposition parties, the Social Democrats and the Greens, staunchly oppose the idea of keeping the plants online longer, citing the safety risk and the need to switch to renewable energies.

Opposition leader Sigmar Gabriel said the agreement marked "a black day for Germany's energy policy," German news agency dapd quoted the Social Democrat as saying.

The party's deputy leader Andrea Nahles said: "They are selling safety for money."

The opposition has said it would ask the country's constitutional court to decide on whether the deal needs parliamentary approval from both chambers.

Merkel says the measure only has to be approved by the lower house, where her government holds a majority. But the opposition says the upper house representing the federal states — where Merkel recently lost her majority — has to approve the measure as well.

The nuclear agreement underscores a shift in energy politics in Europe.

Swedish lawmakers in June narrowly approved replacing aging nuclear plants with new ones and Italian Premier Silvio Berlusconi has made constructing reactors one of his government's goals.

Swedes voted in a 1980 referendum to gradually phase out the use of nuclear power, and Italians rejected nuclear power in a 1987 referendum following the Chernobyl disaster.

Berlusconi's quest on Sunday got new support with a study led by the chief economist of the Paris-based International Energy Agency, Fatih Birol, which recommended the country build nuclear reactors.