Germany's private sector activity contracted to its weakest level in a year and a half in June, according to a new purchasing managers' index (PMI) survey.
The composite index, which covers both manufacturing and services, fell further, indicating that the economic downturn in Europe's largest economy is accelerating rather than stabilizing.
The decline reflects broad-based softening across the private sector, with both industrial output and service demand showing signs of strain.
This deterioration comes as global growth concerns intensify, with similar deceleration patterns emerging in other major economies.
India's private sector expansion slowed to its weakest pace in three months, while China's economy has shown signs of faltering after a strong start to the year.
The German data adds weight to fears that the eurozone's engine of growth is struggling to find momentum.