Staff at discount grocer Aldi Sud have “strongly recommended” that the retailer should increase its range of branded products, according to German press reports.

The discount grocer – split into two companies in Germany, Aldi Sud and Aldi Nord – is reported to have suffered a 5 per cent fall in sales in its home market during the first five months of this year, according to data from market research agency GfK NOP.

Aldi has the lowest penetration of brands in Germany’s grocery retailing, standing at less than 10 per cent.