Sparda-Bank Berlin eG will start charging a negative 0.4% annual interest rate on overnight deposits exceeding €100,000 from Sept. 1 and will calculate the rate on a quarterly basis, Handelsblatt reported June 2, following up a previous report by the Frankfurter Allgemeine Zeitung.

Sparda becomes the largest cooperative bank in Germany to impose such a charge; it ranks 15th by balance sheet total among the roughly 1,000 cooperative credit institutions in Germany.

The move will affect nearly 5,000, or around 1%, of Sparda's customers, according to Handelsblatt. The bank is in the process of contacting customers likely to be affected.