German investor confidence kept up a sharp rebound in May after surging in April, a closely-watched survey shows, reflecting "confidence in an economic turnaround" after blows from Covid-19.

The ZEW institutes's monthly barometer of economic expectations for the coming months leaped 22.8 points this month for a reading of 51, continuing to shake off a steep plunge into negative territory in March. 

"Confidence is growing that an economic turnaround will begin in summer," ZEW chief Achim Wambach said in a statement. 

"Nevertheless, it will take a long time to get back to where we were," Achim Wambach added, saying the roughly 200 financial market experts surveyed see output returning to last year's levels only in 2022. 

Germany is inching out of a nationwide lockdown imposed to slow the virus' spread, with shops, restaurants and factories gradually reopening. 

Corresponding to the slow restart, the ZEW index measuring views of the present economic situation for Europe's top economy fell back slightly, remaining deep in negative territory at -93.5 points. 

Survey respondents' views of the economic situation in the 19-nation euro zone were also negative at -95 points.

But the outlook for the currency bloc also surged more than 20 points in May, landing slightly below German expectations at 46. 

While Germany has been affected less than neighbours like France, Italy or Britain in numbers of deaths from the coronavirus, shutdowns across Europe and further abroad have hit its interconnected economy hard. 

Hoping to kick-start an economic rebound, Chancellor Angela Merkel and French President Emmanuel Macron presented plans this week for a €500 billion European recovery fund to be backed by joint debt.

While other capitals remain to be convinced, the plan represents a retreat from German opposition to any form of shared debt between the EU's 27 member nations.