Gross gas production was 0.7% higher year-on-year at 25.39 million boe in the January-September period of this year, Romgaz said in a bourse filing.
Own gas delivered to market fell 2.6% on the year to 37.1 TWh in the review period.
The company's electricity output plunged 61.1% to 292.1 GWh.
Invoiced UGS withdrawal services fell 18.2% to 924.4 million cm, while invoiced UGS injection services grew 41.1% to 2.27 billion cm.
In the third quarter alone, hydrocarbon production fell by an annual 2.3% to 8.06 million boe, as gross gas production decreased 2.5% to 8.03 million boe.
Romgaz will publish its 9-month consolidated financial statement on November 14.
As at 11:00 CET on Wednesday, Romgaz shares traded 0.13% lower at 38.35 lei ($8.95/8.06 euro).
(1 euro = 4.7603 lei)