Russia took the crown from Saudi Arabia as the biggest oil producer in the world in December.
The nation pumped 10.49 million barrels a day (b/d), down 29,000 b/d from November.
Saudi Arabia also saw a fall in output to 10.46 million b/d in December from 10.72 million the month before, according to new statistics from the Joint Organisations Data Initiative.
The US was said to be the third largest producer, at 8.8 million b/d in December. Iraq came in fourth at 4.5 million b/d, followed by China at 3.98 million b/d.
Last year, Saudi Arabia and other producers from the Organisation of Petroleum Exporting Countries (OPEC) decided to restrict supplies by 1.2 million b/d for six months starting in January this year.