Department store and mail order group KarstadtQuelle on Monday reported doubled first-half losses of 348 million euros, blaming a fall in consumer spending and tourism for its slide deeper into the red.

Sales revenue fell 3 per cent to 7.4 billion euros, with department store sales were down by over 10 per cent.

Releasing the figures, KarstadtQuelle said costs of straightening out the business had played a role in the loss.

Chief executive Wolfgang Urban predicts full-year sales will be 3 per cent lower. But he said the company could offset the downturn in sales "restructuring successes and additional optimisation programs" - which could include additional job cuts. The group, which employs a total of 104,000 people, axed 7,700 jobs last year.