Next month, legislation passed by the French government will require Electricite de France to sell power to its rivals. The European Commission is examining the law's impact on competition.
"They may take months to study its effects on the French market," said Jean-Paul Tran Thiet, a Paris-based partner at White & Case, referring to the Commission.
The company will sell 61.3 terrawatt-hours in the next six months to other power suppliers, France's energy regulator said on its website.
The sale this year of about two-thirds of the maximum 100 terawatt hours of EDF's nuclear output is "a significant start," Tran Thiet said.