ECB action eyed
The pan-European FTSEurofirst 300 index closed provisionally lower by 0.9 percent at 1,356.67 points.
The lackluster growth data came as anxiety has spread across global markets, with concerns centered around deflation in Europe, hefty stocks valuations and ongoing tensions in Ukraine.
In an ECB survey, professional forecasters cut their outlook for inflation in the euro zone on Thursday morning, boosting fears the region was heading for stagnation.
The euro fell to a 11-week low after the survey and stocks retreated, as investors put money into fixed income, seen as a safer investment option.
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However, expectations are growing that the ECB could take act against deflation at its next Governing Council meeting in June.
ECB Vice President Vitor Constancio said on Thursday that the central bank was ready to act if needed, but said there were no distinct signs of deflation in the euro bloc.
Among the policy tools available to the bank are a further cut to interest rates, a negative deposit rate or even a Federal Reserve-style quantitative easing program.