Rewe, with a presence in 12 European countries, is the third-largest retailer in Europe.
But most of the Cologne-based group's sales are still made in Germany.
Rewe was founded in Cologne in 1927 and is now owned by some 3,000 independent merchants.
Last year, the group made total net sales of SFr57.5 billion ($43.8 billion), of which almost SFr49 billion consisted of sales in Germany.
Of Rewe's total 11,000 retail outlets, 8,600 outlets are in Germany, while 140,000 of its total 187,000 employees are also Germany-based.
Food sales, both wholesale and retail, are the core business for Rewe, representing 82 per cent of its total sales.
Following Wednesday's acquisition of a 53 per cent stake in the Swiss food and household goods retailer, Bon Appetit, Rewe expects the proportion of foreign food sales to increase to 32 per cent.
Rewe's supermarket chains include Penny and MiniMal.
Among Rewe's other businesses are a tourism division, including some 1,100 travel agencies.
swissinfo with agencies