The move could open the way to a deal worth more than 500 million euros ($542 million) for Edison, which last year decided to test the market's appetite for its storage business saying it did not see a big growth potential for the division.

Snam, which manages Italy's domestic gas network, already operates the bulk of the country's storage system. Regional energy company Ascopiave was also in the race to buy Edison's assets.

($1 = 0.9224 euros)

(Reporting by Francesca Landini; Editing by Chris Reese)