The market value of the stake is around 400 million euro, Jutarnji List private daily reported quoting unnamed sources.
MOL owns 47.15% of INA and the government in Zagreb holds a stake of some 44%.
INA explores and drills for oil and gas in Croatia, Angola, Egypt, Syria and Iran. It owns two refineries in Croatia and runs the biggest domestic fuel retail chain.
INA’s shares, which are traded on the Zagreb Stock Exchange, closed up 0.68% at 1,788 kuna ($366/246 euro) on Tuesday.
(1 euro=7.2812 Croatian kuna)