A survey is showing an unexpected decline in German investor confidence following disappointing industrial production and export figures.

The ZEW institute said Tuesday its monthly index measuring investors' economic outlook for the next six months declined to 36.3 points in July from 38.5 in June. Economists had expected an increase to 39.8.

However, the index remains well above its historical average of 23.7.

ZEW president Clemens Fuest said market experts remain generally positive, illustrating "their confidence in the robustness of the German economy despite the rather weak figures concerning industrial production and foreign trade released recently."

Germany so far has weathered Europe's debt crisis relatively well — helped by its traditional export strength and a robust job market that is fueling domestic demand.