Sumitomo Coal sells imported coal, and generates a significant share of earnings from building materials and machine components. The company is entering new fields such as real estate and retailing. Plans call for the further diversification of operations. A diversified mining organization, Nittetsu Mining generates the largest share of sales from limestone for makers of steel and cement. The company is Japan's number one supplier of limestone.
Sales also come from copper, environmental operations and fine chemicals, as well as real estate.
Nittetsu Mining has large unrealized capital gains on real estate holdings. A trading company, Mitsui Matsushima derives most revenues from domestic and imported coal. Diversification is taking the company into sales of concrete and the retailing field. Teikoku Oil produces and sells petroleum and natural gas. Most gas is sold to utilities for household use.