The deal includes the supply of 18 wind turbines for the 58 megawatt (MW) onshore wind farm Korlat, located near the town of Benkovac, as well as its maintenance for a period of 20 years.
The project would also be the first power plant in Croatia to generate electricity without incentives, Frane Barbaric, the president of HEP's management board, said in a statement, without disclosing the deal's value.
The wind farm will produce 170 gigawatt hours (GWh) of electricity a year, some 1.5% of Croatia's electricity demand.
HEP said earlier it aimed to boost renewable energy to 50% of its total capacity from the current 35%, investing 1 billion Croatian kuna (121 million pounds) a year on average until 2030.
Croatia, the European Union's youngest member, currently imports 40% of its electricity, around 60% of its gas and up to 80% of its oil.It has 4,500 MW of installed power generation capacity with HEP controlling 85% of the electricity market.
(Reporting by Maja Zuvela; editing by David Evans)