Investment sentiment in Germany fell to its lowest level in nearly one and a half years in May amid concern recovery in Europe's top economy will lose momentum, a new survey found today. 

The widely watched investor confidence index calculated by the ZEW economic institute fell by 10.1 points to 33.1 points in May, it said in a statement.

Analysts had been projecting a much softer drop to 41 points. 

"Already, there are indications that Germany will not be able to maintain this fast pace of growth," said ZEW president Clemens Fuest.

"Nevertheless, one can assume a positive underlying trend for the economic development for the year 2014. The decline of the experts' economic expectations for Germany should be seen against the backdrop of a strong economic development in the first quarter," Fuest said. 

For the survey, ZEW questions analysts and institutional investors about their current assessment of the economic situation in Germany, as well as their expectations for the coming months. 

The sub-index measuring financial market players' view of the current economic situation in Germany rose by 2.6 points to 62.1 points in May its highest level since July 2011. 

A frequent criticism of the ZEW index is that it can be volatile and is therefore not particularly reliable.