Ratatics replaces Sándor Fasimon, who resigned earlier in September amid revelations of fraudulent gas trade deals that took place under his watch.

Fasimon tendered his resignation "despite no involvement in any of the wrongful practices that surfaced around INA," the Croatian subsidiary said earlier.

MOL's other two delegates to INA's board also resigned.

Late in August, Croatian authorities took five people into custody, including the head of INA's gas trade business, Damir Skugor, suspected of defrauding INA of more than HRK 1 billion through gas deals on international markets.

Croatia's government called for the dismissal of INA's entire board over the case of fraud.