EDF said the power unions blocking work at the plants have until Tuesday to sign an agreement on general wage increases for their sector.
It did not give any details on the agreement but said company-level discussions - which can offer additional wage increases - on ending the strike will begin whether the agreement is signed or not.
The strike, which is now affecting one-third of French nuclear plants, started last month as part of wider union movement to seek higher wages and has reduced French electricity production.
France usually produces about 70% of its electrical output with nuclear energy.
"Maintenance operations are continuing on the reactors that are currently shutdown despite the local social movements," the spokesperson added.
However, the strikes have already caused delays to the outage schedule for six reactors, and have delayed the shutdown of two reactors that were supposed to begin maintenance last week, EDF data showed.
The strike can also cause the temporary power drops for reactors that are in production. Supply from the Gravelines 1 and Paluel 4 reactor were lowered 700 megawatts (MW) in total this morning, the data showed.
"In all situations, safety shall remain assured," the spokesperson said.
The disruption could slow EDF's plans to return the nuclear fleet from its recent low capacity after delayed maintenance and stress corrosion problems dropped production to a 30-year low in 2022.
France has become a net importer of electricity this year due to the problems with its nuclear fleet, increasingly relying on neighbours who are scrambling to find gas following the disruptions caused by the war in Ukraine.
French nuclear availability is currently at 45% of installed capacity with 30 reactors offline for maintenance.
The strike is part of a larger social movement throughout France - over wage demands, pensions and purchasing power as inflation spirals across Europe - that has seen refining strikes restrict fuel supply throughout the country.
