MILAN, Dec 13 (Reuters) - Italian oil and gas group Eni ENI.MI said on Tuesday it had reached an agreement with Algeria's Sonatrach over gas supplies for the gas year 2016-2017.

No financial details were provided.

Eni, the biggest foreign oil and gas operator in Africa, said the agreement covered almost 20 percent of the gas imported into Italy.

"I am particularly pleased with the closing of the renegotiation on the gas supply contract and the level of the strategic partnership with Sonatrach," Eni CEO Claudio Descalzi said.

(Reporting by Stephen Jewkes; editing by Francesca Landini) ((stephen.jewkes@thomsonreuters.com; +39.0266129695; Reuters Messaging: stephen.jewkes.thomsonreuters.com@reuters.net))