German industrial output fell unexpectedly for the second month in a row in January and exports also sank, data showed today.
The latest figures added to signs that Europe's largest economy started the year on a weak footing.
Analysts said the data did not signal a structural slowdown but was largely seasonal.
Economic activity in Germany typically slows down in the winter months because of extended holidays.
German industrial output fell by 0.1%, its second consecutive fall after a dip of 0.5% in December and confounding expectations in a Reuters poll for a 0.5 percent rise, data from the Economy Ministry showed.
Separate figures from the Federal Statistics Office showed both exports and imports had fallen unexpectedly by 0.5% in January, undershooting a Reuters forecast for a 0.3% increase in exports and stagnating imports.
The seasonally adjusted trade balance was unchanged at €21.3 billion, the data showed.
The figures come one day after industrial orders slumped by a more than expected 3.9% in January.
Analysts said that the weak start to the new year is nothing new for the German economy.
They said it was a phenomenon witnessed more often in recent years that German economic data has been overly sensitive to seasonal effects and vacation planning.
Unusually warm weather in January resulted in activity in the energy sector falling by 3.3%. Construction sank by 2.2%, a breakdown of the output data showed.
Manufacturing output was also hampered by workers' strikes.
However, the prospects for the German economy look rosy, with capacity utilisation at its highest level since 2008 and companies reporting full order books.
US President Donald Trump's import tariffs are one of the main risks for Germany, which last year exported more to the United States than any other country.
German Economy Minister Brigitte Zypries told her US counterpart in a letter this week that the tariffs could prompt other countries to use national security as a reason for introducing trade restrictions, which would undermine global trade rules.
But Dieter Kempf, president of Germany's BDI industry association, said he did not believe the era of free trade was over after Trump's announcement of tariffs on steel and aluminium imports.
He said the European Union, which has threatened to impose its own tariffs on US imports in retaliation, should not over-react to Trump's measures.
But "the US needs to feel some pressure", he added, urging dialogue to avoid an all-out trade war.