Petrol operates some 470 filling stations in Slovenia, Croatia, Bosnia, Serbia, Montenegro and Kosovo. It said the underperforming economy in its biggest markets, Slovenia and Croatia, was seriously hampering its business.

Slovenia is struggling to avoid an international bailout because of its crumbling banking sector, while Croatia has had five years without growth. "Slovenia and Croatia have been facing adverse economic conditions for several years, reflected in a decline in business activity, poor payment discipline, insolvency and bankruptcies, decline in private consumption and increased unemployment," Petrol said.

"These harsh conditions are still worsening." Petrol gave no forecasts for full-year sales or profit, and said only it would try to reduce the impact of negative economic trends.

The nine-month profit compares with a net profit of 41.9 million euros in the same period last year. This year's sales were up at 2.9 billion euros versus 2.8 billion euros in 2012, it said in a statement released through the Ljubljana Stock Exchange.

Petrol shares were not active on Friday, after closing at 220 euros on Thursday. They hit a high for the year in January of 260 euros and are down 7 percent from that level.