I.G. Farben
I.G. Farben, more formally I.G. Farbenindustrie AG, started as a 1925 merger of German synthetic dye companies a major WWII industrial conglomerate was an integral part of Nazi war production. Executives, 24 of which were indicted in the I.G. Farben Case (NMT) were deeply involved in the planning process as well — for example, the Auschwitz-Monowitz Concentration Camp was built specifically to provide slave labor to nearby Farben plants, especially those producing synthetic rubber. Farben companies were key parts of German explosives production. They were even part of the production of Zyklon B used as a killing agent in death camps.
The founding companies, most of which now operate independently, were:
Its corporate headquarters complex, the IG Farben Building, was minimally bombed in World War II, and was used until 1995 for Allied and U.S. command offices, and memorials to the victims of slave labor.