Trading houses Mitsui & Co. and Sumitomo Corp. have agreed on a wide-ranging business tieup that includes integrating their sales of construction materials and steam coal, a Mitsui spokesman said Tuesday.

The alliance also calls on Mitsui to join Sumitomo's online sales of tools and other goods and materials for plants by taking a roughly 20 percent stake in a joint venture Sumitomo has launched with U.S. distribution giant W.W. Grainger Inc., he said.

The April 1 launch of Sumitomo Mitsui Banking Corp., the result of a merger of Sakura Bank and Sumitomo Bank, is behind the alliance between the two trading firms, industry analysts said.