Under the codename "Project 6" or "P6", Germany's BND and Verfassungschutz intelligence services and the CIA monitored and collected data on Islamists and suspected terrorists in Germany, the magazine said, without revealing its sources.
The US and German services jointly rented premises in the western town of Neuss in 2005, before subsequently moving to Cologne, the weekly said in a pre-release of an article to be published in its tomorrow's edition.
Der Spiegel said the BND had confirmed the existence of the database, but said the cooperation ended in 2010.
In the run-up to the general elections in two weeks, there has been widespread disquiet in Germany over reports of sweeping US online surveillance and German cooperation, sparked by fugitive intelligence analyst Edward Snowden.
According to the reports, the US National Security Agency (NSA) has hoovered up German emails, online chats and phone calls and shared some of it with the country's intelligence services.
