France's nuclear giant Areva will cut 1,300 jobs in Germany and close down two of its sites after Berlin's decision to abandon nuclear energy, news weekly Der Spiegel reported on Sunday.

The firm will slash its workforce by around 20 percent at its main site in Erlangen in central Germany, as well as making cuts at other sites across the country, Spiegel said, without citing its sources.

The extent of the job cuts would be nearly twice as high as the 800 redundancies cited in the French press. The company is expected to announce the move on December 13 in Paris.

In the wake of the Japan nuclear disaster in Fukushima, the German government decided to shut down all of its nuclear reactors by the end of 2022.

Last week, EON, Germany's biggest power supplier, said it would file a complaint with Germany's highest court, demanding compensation.

The decision is already affecting the bottom line for energy companies.

RWE, Germany's second-biggest power supplier, said earlier this month that it plunged into the red in the third quarter, not least as a result of the country's decision to phase out nuclear power.