The original arbitration initiated by Eni aimed at a downward price revision of the long-term gas supply contracts with the Dutch group for the four years starting in 2012.

Although the arbitration panel did not determine a new price for the contracts, GasTerra claimed an additional amount to be paid by Eni and obtained the provisional seizure of a part of Eni International BV, the Italian group added.

Eni said it did not agree with the GasTerra interpretation and consequently its upcoming results for the first half of the year would not be impacted.

"GasTerra's request for payment is unfounded and (Eni) will take all necessary measures to protect its rights... and will seek further compensation for any damages it incurs," the Italian energy group said in a statement.

(Reporting by Giulia Segreti, editing by Francesca Landini)