The composite output index the euro zone in June dropped to 56.3 from 56.8 in the previous month, higher than the flash estimate of 55.7.
The figures show that euro area's economic growth accelerated to 0.7% in the second quarter of 2017. In the first quarter, the eurozone's GDP grew at a 0.6% compared to the three previous months.
New orders rose and companies face difficulties in meeting the increased demand, Chris Williamson, chief business economist at IHS Markit, said.
Final data from IHS Markit may prompt the European Central Bank to discuss the possibility of cutting some of the stimulus, although monetary policy in the euro zone is likely to remain easy in the foreseeable future.