EON, RWE and Vattenfall told AFP they stopped payment, starting this month, to the fund created in January as compensation for the government's decision last year to prolong the life of 17 nuclear plants by more than a decade, until the mid-2030s.
According to Der Spiegel, energy firm EnBW has also stopped payment.
The government reversed its decision after the Japan nuclear accident last month, imposing a three-month moratorium on the extension plans, and closing the seven oldest nuclear plants.
"We have decided to stop paying," at least for the duration of the government moratorium, EON spokesman Josef Nelles told AFP.
The four companies together were supposed to contribute €300 million (about $430 million) to the fund in 2011, he said.
"We will stop paying; this will start with the April contribution," added a spokeswoman for Vattenfall Europe, a subsidiary of the Swedish group by the same name.
"The very existence (of the fund) was conditioned on the prolongation of the life of the plants. As this prolongation was suspended, we are also suspending our payments. We will not pay until this issue has been clarified."
According to RWE spokesman Martin Pack, it was "contradictory" to expect the companies to continue making payments to a fund whose existence was preconditioned on extending the life of the nuclear plants.
RWE has filed a legal challenge to the government's order to shut its plants. The government communications service said it took note of the companies' decision.
"The government is currently examining the financial consequences of the moratorium," a spokeswoman said, adding that once clarity has been obtained, it "may lead to a modification of the accord with the energy groups."