French industrial production unexpectedly fell 0.8% in June from May, figures from the INSEE official statistics agency showed, due largely to a decline in refinery activity during nationwide strikes.
A Reuters poll of 22 economists had an average forecast for a rise of 0.1% with estimates ranging from -1% to +1.3%.
The decline was driven by a 12.4% drop in the refining sector, INSEE said, following a 21% decrease the previous month, as strikes at Total's refineries disrupted production.
The French oil major was only able to resume production around the middle of June after the 27-day strike.
But June output was also down 2.6% in the equipment goods sector, and 1.7% in the transport material sector, with only the mining, energy and water sector expanding with a 1.9% rise.
Over the second quarter as a whole, industrial production was down 0.1% from the previous quarter, and up 0.4% from the same quarter a year ago.
