German investors' confidence slumps for fifth month in August

German investors' confidence weakened for the fifth consecutive month in August due to concern about global economic prospect, a survey found on Tuesday.

An indicator measuring German investors' confidence slumped to 25 points in August from 29.7 points in previous month, said Mannheim-based Center for European Economic Research (ZEW) in a statement. This was the fifth drop in a row.

According to the think tank, the drop was due to investors' concern about global economic prospect.

"The German economic engine is still running smoothly. However, under the current geopolitical and global economic circumstances a substantial improvement of the economic situation in Germany over the medium term is improbable," said ZEW President Clemens Fuest.

The German economy was traditionally export-oriented, but relied on domestic demand in recent years as the global economy remained sluggish and its euro zone partners struggled to revive from crisis.

In the first quarter of 2015, Germany's gross domestic product (GDP) increased mildly by 0.3 percent, mainly thanks to robust private consumption supported by stable labor market, increasing wages and low interest rates, down from a growth of 0.7 percent in the last quarter of 2014.

Official data of German economic growth in the second quarter was scheduled to be released on Friday. Economists expected Europe's biggest economy to expand at a higher speed than at the start of this year.