The offer to minority shareholders will be priced at 12 euros per share, meaning the operation to fully nationalize the group will cost 9.7 billion euros ($9.9 billion).

The electricity provider is currently 84-percent owned by the state, with institutional and retail investors holding 15 percent and staff one percent.

EDF's finances have been weighed down by declining output from France's ageing nuclear power stations, which it manages, and the state-imposed policy to sell energy at below cost to consumers in an effort to help them pay their energy bills.

EDF will need to spend about $50 billion fromnow to 2030 to extend the life and fix up existing nuclear reactors.