RTE said it had been able to increase the capacity of the interconnector between the Belgian town of Avelgem and the French town of Avelin to 6 gigawatts (GW) from 3 GW without having to install a new line by making use of high performance electrical conductors.

"This solidarity is essential in the midst of the energy crisis but also in the longer term to achieve our carbon neutrality objectives," President of the Managing Board at RTE Xavier Piechaczyk said.

French utility EDF has faced an unprecedented number of outages at nuclear reactors this year, reducing output to a 30-year low when Europe is racing to replace Russian gas supplies.

(Reporting by Forrest Crellin; editing by Barbara Lewis)