The First World War hit Metallgesellschaft hard. The good relations established abroad were broken off, imports of raw material dried up, the sister company HRM fell under the British Non-Ferrous Metals Industry Bill of November 1917, designed to eliminate enemy influence and control over the British ore and metal trade, and the deliveries of Australian ore failed to appear. This meant Metallgesellschaft had to obtain its metal supplies from neutral countries for as long as possible and eventually to use up domestic sources or intensify their exploitation. Three aluminum works were built, in conjunction with the firm Griesheim Elektron: in Horrem, close to Cologne; in Berlin-Rummelsburg; and in Bitterfeld near Halle.