Fuel sales rose 3.6% on the month in July in data adjusted for the number of working days and seasonal factors, while non-food sales were up 1.3%, INS said.
Sales of food, drinks and tobacco increased 0.9% in July from the previous month.
In annual terms, adjusted retail sales inched up 0.1% in July, held back by a 4.1% decline in food sales.
On the other hand, fuel sales rose 3.2% on the year, while non-food sales were up 1.6%.
In the January to July period, Romanian adjusted retail sales declined 5.2% on the year, due to falling consumption in all sectors, the data showed.