EON SE E.ON (>> E.ON SE), RWE (>> RWE AG) and Vattenfall [VATN.UL] filed complaints with the Constitutional Court after the government imposed a stricter closure timetable in 2011 as a result of the Fukushima nuclear disaster in Japan.
While not opposed to the closure plans in principle, the firms claim the move to accelerate the pace of shutdowns in the run-up to the 2022 deadline violated their property rights and resulted in billions of euros in damages and losses.
They have also incurred losses by having to buy power from the market to meet commitments they could no longer fulfil once the nuclear plants were shut, and stand to face higher decommissioning costs than anticipated.
The court will not decide on individual damages claims - estimated to total at least 15 billion euros ($17 billion) - but its decision could provide the legal basis for such motions should it rule the government's decision is illegal.
The court spokesman said he could not be more precise about the timing of the ruling, adding it still needed to be decided whether a hearing would take place.
RWE, Germany's second-biggest utility, said it expects a ruling in the second half of the year.
The complaints are part of a number of legal steps being pursued by RWE and its peers over Germany's nuclear policy, including a nuclear fuel tax and the immediate three-month shutdown of all of its nuclear power stations following the Fukushima disaster.
($1 = 0.8787 euros)
(Reporting by Tom Kaeckenhoff and Christoph Steitz; Editing by Maria Sheahan and John Stonestreet)
