In August, industrial sales fell 10.4% month-on-month.
Manufacturing sales increased 11.6% on the month in September, while mining sales were up 5.4%, the data showed.
By segment, sales of capital goods rose 32.7% in September from a month earlier, while sales of durable and intermediate goods increased 12% and 8.2%, respectively. Energy sales were up 7.6% on the month, but consumer goods sales declined 2.5%.
On an annual basis, industrial sales rose 6.1% in September, supported by a 6.4% increase in manufacturing sales. Mining sales fell 3% year-on-year.
In the first nine months of 2013, Romanian industrial sales rose 4.4% on the year, fueled by a 4.7% increase in the manufacturing sector.