The first part of the transaction is to be realised by the end of the year, following the fulfilment of suspensory conditions. The second part of the transaction is expected by the end of June 2018, reads Petrol's press release on the website of the Ljubljana Stock Exchange.

The subject of the sale, Gen-I, holds a 50% stake in the buyer Gen-EL, with the remainder of the stock divided equally between Gen Energija and Petrol.

In turn, Gen-I has been since 2011 in Gen Energija's (50%) and Petrol's (50%) ownership. Petrol bought its stake through subsidiary Iges, which it had bought in 2011 for EUR 25m.

Papers reported in September last year that Petrol had been gearing up to sell its stake in Gen-I, the biggest electricity retailer in Slovenia.

Reports said that Croatian national power company HEP and the Slovenian state-owned Gen Energija had been potential buyers, with Gen reportedly having the pre-emptive right.

HEP, which has been aggressively entering the Slovenian market, and Gen Energija together operate Slovenia's nuclear power station NEK Krško, whose electricity Gen-I sells.