(ANSA) - BELGRADE, JUN 16 - According to a government decision released late Monday, diesel prices in Slovenia increased at midnight, while petrol prices at pumps outside the motorway remained unchanged, the Slovenian news agency STA reports today. Regular petrol remained at EUR 1.592 per litre, while diesel rose by 3.3 cents to EUR 1.718 per litre. The most recent fuel price adjustment comes after the new government extended price regulation of fuels sold outside the motorway network for another six months last week. Retailers set the prices of fuel sold at motorway pumps. (ANSA).