Negative deposit rates are hurting savers' ability to make money, Erste Bank CEO Andreas Treichl told CNBC ahead of the European Central Bank Meeting in Vienna on Thursday, adding that the lack of investment options in the bank's key markets needed to be addressed.

"Negative deposit rates are bad for the clients, they're not necessarily so bad for the banks because we have two sides of the balance sheet so it's really bad for the mass market clients," Treichl said. "Actually it's bad for about 90 percent of the population in our region who have no means to invest in anything else but bank deposits," said Treichl.