Under the agreement, EIP will enter Plenitude's share capital through a capital increase of up to 700 million euros, which, post-transaction, would be approximately 9% of the company.

The deal is expected to set a floor for the price of Plenitude in a potential future listing on the Milan stock exchange.

"Thanks to this transaction we highlight the value of Plenitude within Eni, we strengthen Plenitude's financial structure to further support its energy transition and growth path, and we establish a long-term partnership with a leading international financial investor," Eni Chief Executive Claudio Descalzi said in a statement.

Under Descalzi, Eni is applying what it calls a 'satellite' approach to create independent units specialising in specific activities and able to attract investors focused on those businesses.

Rothschild has acted as financial adviser to EIP.

($1 = 0.9136 euros)

(Reporting by Francesca Landini; editing Gianluca Semeraro and Jason Neely)