German industrial production rose less than expected in April and economists said the outlook for Europe's largest economy remains weak, despite an unexpected increase in exports. Industrial production rose by 0.4% in April compared with the previous month, the federal statistics office said on Tuesday. Analysts polled by Reuters had predicted a 0.5% rise. It was the first monthly increase since the start of the Iran war, but that was no cause for optimism, Carsten Brzeski, global head of macro at ING, said.