The total cost was 8.9 billion euros ($12.1 billion) compared with 9.9 billion euros in the same year-earlier period.
The amount of gas imported in Jan-April fell by 2.2 percent year-on-year to 1,231,148 terajoules(TJ), in contrast to strong year-on-year volume rises in preceding months up to February, in a winter that was more severe than that of 2012/13.
Many continental European gas prices, including those recorded by BAFA, still track crude oil prices with a time-lag of about six months.
BAFA prices are used in the domestic market to monitor the cost of imports and to decide whether gas is competitive compared with other fuels.
Russia accounted for 36.9 percent of deliveries in the period under review, Norwegian-origin gas accounted for 32.5 percent and the Netherlands for 25.7 percent in the four months.