Last week, the Council of State, France's highest administrative court, cancelled government limits on scheduled 2014 power rate increases and ordered the government to recover the shortfall.
The 2014 payments correspond to about 4 percent of EDF's 2015 core earnings before interest, tax, depreciation and amortisation (EBITDA).
Moody's said the ruling is credit positive for EDF's A2 rating because a tariff catch-up would boost its revenue and EBITDA. Energy Minister Segolene Royal has said the ruling would boost EDF's 28 million residential customers' bills by 1.5 euros per month over 18 months.