According to a report in German financial daily Handelsblatt, Vattenfall is already finalizing a complaint, and is preparing to file it before Christmas.
German energy companies E.ON and RWE have already filed legal complaints against Germany's plan to phase out nuclear power, but as a foreign company, Vattenfall can invoke the Energy Charter Treaty (ECT), an international agreement that provides a multilateral framework for energy deals.
Vattenfall did not comment on the report, though it said it was expecting “compensation for the phase out from nuclear energy.”
The ECT protects foreign investors against violations of their property rights. Article 10 of the treaty, signed by 51 countries plus the European Union, says each signatory will “encourage and create stable, equitable, favourable and transparent conditions for investors,” and will ensure “fair and just treatment” for investors.
Speaking with the Svenska Dagbladet (SvD) newspaper, Vattenfall spokesperson Maria Lidzell refused to elaborate on the Handelsblatt report.
“No decision has been taken. We can neither confirm nor deny what's in Handelsblatt,” she told SvD.
Vattenfall is claiming that it stands to lose €700 million ($957 million) it had invested in the nuclear power stations Krümmel and Brunsbüttel after the government originally agreed to extend the life-spans of its nuclear power stations.
Both of those reactors were shut down permanently earlier this year after Angela Merkel's government performed a dramatic U-turn in its energy policy in the wake of the Fukushima nuclear disaster in Japan.
Germany's last nuclear power stations are set to be shut down permanently in 2022.
Vattenfall is also complaining that the surplus energy that the reactors had already generated is now no longer worth much, since many reactors are being shut down even quicker than planned.
Vattenfall has successfully appealed to the ICSID against Germany in 2009, over lost income because of stronger environmental regulations on a coal power station near Hamburg. The company settled with the German government for an undisclosed sum.