Output fell to 3,918 billion cubic metres (bcm) with North American production hardest hit, Rystad Energy estimates showed, lower than a previous estimate.
Reflecting the impact of lockdowns to curb the spread of the coronavirus, demand in Europe fell by 7%, or 40 bcm
Gas emits roughly 50% less CO2 than coal when burned in power plants, but it is associated with leaks of methane, a potent greenhouse gas.
Envoys from the EU's 27 member countries endorsed the deal on Wednesday, which was struck between EU governments and the European Parliament last week.