At the top of the corporate system are three general types of corporate groupings. The first includes the corporate heirs of the Zaibatsu, (including many of the same firms). The second consists of corporations that formed around major commercial banks. The nation's six largest groupings are in these two categories. Mitsui, Mitsubishi, and Sumitomo are former zaibatsu, while other groupings were formed around the Fuji-Sankei, Sanwa, and Dai-ichi Kangyo banking giants. A third type of corporate grouping developed around large industrial producers.