Eni SpA (E), Italy 's biggest energy company by market value, Monday said it completed the sale of a controlling stake in natural gas grid and storage company Snam SpA (SRG.MI) to Cassa Depositi e Prestiti SpA for 3.52 billion euros ($4.54 billion).

Eni said it sold a Snam stake of 30% minus one share to state-controlled lender CDP, as initially agreed on May 30.

The
Rome --based company received EUR1.76 billion Monday from CDP, while the rest will be in two successive tranches, with the first by Dec. 31 and the second by next May 31.

Eni is controlled by the Italian government, as is Snam.

Eni said its net debt will drop by EUR14.7 billion following the sale of the Snam stake.