Berlin - Germany said Thursday its trade surplus narrowed in September compared to a month earlier, with exports falling more than imports at a time of high tensions in global commerce. After calendar and seasonal effects were taken into account, the surplus stood at 17.6 billion euros for September from 18.2 billion euros in August, data from federal statistics office Destatis showed. The narrowing surplus came as exports declined 0.8 percent compared to August, while imports dipped at a slower pace of 0.4 percent. "A combination of slowing world trade and temporary factors like the new emissions norms for autos hit the German export sector over the summer months," said Carsten Brzeski, chief economist at ING Germany. The softening surplus also came after disappointing industrial production data published this week. "Available monthly data suggests that the economy had its worst quarterly performance in 3Q since the beginning of 2015," said Brzeski.