German business morale deteriorated more than expected in July, hitting its lowest level since April 2013, a survey showed today.

Today's survey is a further sign that a manufacturing crisis is dragging on overall private sector activity in Europe's largest economy. 

The Ifo institute said its business climate index fell to 95.7 from an upwardly revised 97.5 in June.  

The July reading, the fourth monthly decline in a row, undershot a consensus forecast for 97.1. 

"The German economy is navigating troubled waters," Ifo President Clemens Fuest said in a statement.

He also said that companies were less satisfied with their current business situation and are also looking ahead with increased scepticism.