In November 1945, the Allied Forces confiscated the I.G. and placed all its sites under the control of Allied officers. The company was to be dissolved and its assets made available for war reparations. Yet the British permitted Ulrich Haberland (1900–1961), who had been in charge of the Lower Rhine consortium since 1943, to remain in his position. Soon they allowed production to resume as well, as the chemical industry's products were essential to supply the population.

In the years that followed, Haberland worked to build up a new and competitive company in the successful Bayer tradition. The Allied military governments had initially planned to break up the I.G. into as many small companies as possible. Yet these companies would hardly have been able to survive on the world market or even in Germany itself. The Allies finally came to this realization as well, and thus – on the basis of Allied law – 12 new thoroughly competitive companies were created in the Federal Republic of Germany.

One of these companies was Farbenfabriken Bayer AG, which was newly established on December 19, 1951. The Leverkusen, Dormagen, Elberfeld and Uerdingen sites were allocated to the new company, and in 1952 Bayer also received the newly established Agfa "joint stock company for photofabrication" as a subsidiary.