Adds details on Eni's strategy and background on previous transactions from paragraph 3

By Francesca Landini

MILAN, May 15 (Reuters) - Italy's Eni ENI.MI has entered exclusive talks with investment fund Ares Alternative Credit Management over the sale of a 20% stake in its renewable and retail arm Plenitude, the energy group said on Thursday.

Negotiations are based on an equity value of Plenitude between 9.8 and 10.2 billion euros, corresponding to a value of more than 12 billion euros ($13.4 billion), including debt, Eni said in a statement.

The deal is part of Eni's so-called 'satellite' strategy , which aims to develop specialised units dedicated to low-carbon businesses or upstream projects that can attract investments from financial partners.

"The agreement follows a thorough selection process involving several prominent international players who expressed strong interest in the company, further confirming the great appeal of its business model and its growth prospects," the Italian group said.

Mediobanca MDBI.MI is acting as financial adviser for Eni, while UniCredit and Deutsche Bank are advising Ares Alternative Credit Management on the deal.

Under the satellite strategy, Eni has already opened up the capital of Plenitude to Switzerland's Energy Infrastructure Partners (EIP) in two transactions that brought the asset manager to get a 10% stake in the unit.

EIP valued Plenitude at over 10 billion euros, including debt, in the last deal completed in March.

Earlier this year U.S. investment fund KKR KKR.N acquired a total 30% of the energy group's biofuel unit Enilive with overall proceeds for Eni of 3.6 billion euros.

($1 = 0.8939 euros)

(Reporting by Francesca Landini, editing by Giulia Segreti and Louise Heavens)

((francesca.landini@thomsonreuters.com; +39 02 66129437; Reuters Messaging: reutersitaly.thomsonreuters@reuters.net))