Enel Spa plans to invest $3.1 billion in Russia over the next five years, the Financial Times reported Friday, citing the company's Chief Executive Fulvio Conti.

The funds will be used to upgrade facilities at its Russian OGK-5 power generation company, in which it holds a controlling stake of 60%, and launch production by 2010 at the three gas fields it jointly acquired with Eni Spa, Financial Times said.

Enel expects a return on investment "in excess of 13%" once Russia liberalizes electricity prices for industrial consumers, as it has pledged, by 2011.

In Bulgaria, Enel owns 73% of the capital of Enel Maritza East 3, with one of the largest thermoelectric power stations in the country (840 MW) located close to Stara Zagora, in the centre of Bulgaria, and with its head office in Sofia.

Again with a share of 73% of the capital, Enel also controls Enel Operations Bulgaria, the company which manages and maintains the plant.