German business confidence beat expectations by rising slightly in August, reflecting the continued robustness of Europe's biggest economy amid the current financial market turbulence, the Ifo economic institute said Tuesday.

The Ifo institute's closely-watched business climate index rose to 108.3 points this month from 108.0 points in July, beating analysts' expectations for a slight fall, Ifo said in a statement.

"The German economy continues to be a rock in turbulent waters," said Ifo president Hans-Werner Sinn.

"Satisfaction with the current situation has again increased significantly. However, the companies were somewhat less optimistic regarding future business."

Ifo calculates its headline index on the basis of companies' assessments of the current business environment and the outlook for the next six months.

The sub-index measuring current business rose to 114.8 points, its highest level since April 2014, while the outlook sub-index slipped fractionally to 102.2 points, the institute said.