A closely-watched survey shows German investor sentiment surged in June, as confidence in the German economy helped offset concerns about a possible British exit from the European Union.

The ZEW institute said Tuesday its index of economic sentiment for Germany rose to 19.2 points from 6.4 points in May. Economists had predicted a slight decline.

ZEW president Achim Wambach says "financial market experts have confidence in the resilience of the German economy. However, general economic conditions remain challenging."

He added that "apart from the weak global economic dynamics, it is mainly the EU referendum in Great Britain which causes uncertainty."

Investor confidence in the current economic situation in Germany improved by 1.4 points, but dropped 0.8 points for the eurozone.

A total of 202 financial experts were surveyed.