BERLIN, Nov 12 (Reuters) - European Central Bank (ECB) Board member Joerg Asmussen on Tuesday cautioned against charging banks to deposit their spare cash at the central bank but did not rule out the possibility that the ECB might take this step in future.

“I would be very careful with a such a step because it has high signalling effect, but I would not rule it out categorically,” Asmussen told Neue Osnabruecker Zeitung in an interview published on Tuesday.

Several ECB policymakers, including ECB President Mario Draghi, have said that negative deposit rate - that rate is currently at zero - are part of the central bank’s toolbox and could be deployed if needed.

It could however have negative side effects, and markets have been sceptical of the chance of the ECB taking that step.

Asmussen added the ECB had not reached the “end of its limits” on interest rates, indicating there was room for further cuts after the ECB cut its main refinancing rate last week.