Earlier this month China's state-owned utility China Three Gorges launched a bid to take control of Portugal's biggest company in a deal that would be worth 9.07 billion euros (£7.9 billion).

Enel, which controls Spanish utility Endesa, has previously said it is not interested in large-size acquisitions but would consider smaller bolt-on deals.

In an interview with Reuters in April Enel CEO Francesco Starace said the group would look at assets in Europe that came to market from break-ups.

Europe's biggest utility is currently locked in a bidding war with Spain's Iberdrola to buy Brazil's largest power distribution company Eletropaulo Metropolitana SA.

(Reporting by Stephen Jewkes; Editing by Catherine Evans)