From Wikipedia.....
The Aldi group operates about 8,210 individual stores worldwide. A new store opens every week in Britain alone.[3]
Aldi Nord is responsible for the markets in Belgium, the Netherlands, Luxembourg, France, Spain, Portugal and Denmark. Aldi Sd caters to the markets of the United States, Austria, the United Kingdom, Ireland, Australia, Switzerland and Slovenia. Aldi Sd currently is expanding in Switzerland, where the first stores opened in 2005. Hungary, Greece and Poland are on the short list of countries for further expansion, where the first stores opened in 2007.
Whilst Aldi Nord has long renamed its Dutch and Belgian subsidiaries Combi and Lansa to the ALDI Markt/Aldi March brand, Aldi Sd tries to keep a regional appearance. Therefore, Aldi Sd explicitly brands its outlets as Aldi Sd in Germany, Aldi Suisse in Switzerland and Hofer in Austria and Slovenia....
The Albrecht brothers operate Aldi as two parellel, autonomous companies structured so there is no overlap of territories or competition between the two companies yet both companies enjoy significant economies of scale since both are buying from the same suppliers. Since Aldi Sud controls the U.S. market, Trader Joe's is owned by the same entity that owns Aldi Sud (Karl Albrecht).