MILAN, May 17 (Reuters) - Italy's Eni said on Tuesday it had started proceedings to open two accounts with Gazprom Bank to pay for Russian gas on a precautionary basis.

The energy group, one of Europe's biggest importers of Russian gas, said the move followed Gazprom's unilateral request to amend the existing contracts under a new gas payment scheme.

"The Company is going to temporarily open the two accounts without prejudice to its contractual rights, which still envisage payment in euros," Eni said in a statement. (Reporting by Stephen Jewkes, editing by Giulia Segreti)