Retail sales dropped 2% on a monthly basis in September, in contrast to the 1.2% increase seen in August. Sales were forecast to grow 0.4%, the DPA reported.
On a yearly basis, the decline in retail sales deepened to 2.3% from 0.3% in the prior month.
Data showed that sales at petrol stations fell 3.4%. Retail sales of food products slid 1.4% and non-food sales decreased 2.4% from August.
At the same time, online and mail-order sales declined 2.2%.