The Japanese electronics industry is highly concentrated. In 1984 there were twenty-one companies among the top hundred in the electronics sector with net sales in excess of a billion dollars. Of these twenty-one companies nine had net sales in excess of a trillion yen (equivalent to about 4 billion dollars at the exchange rate then prevailing). These companies were: Hitachi, Matsushita, Toshiba, Nippon Electric (NEC), Mitsubishi Electric, Fujitsu, Sanyo, Sony and Sharp. These nine companies produced about one-third of the total output of the electronics sector and accounted for a greater proportion of the sector's exports.

The biggest of these companies in terms of total net sales are diversified companies producing both electronic and electrical products. For example, Hitachi in 1986 had net sales of 5.01 trillion yen (or 27.83 billion dollars). The largest single product division in the company was Information and Communication Systems and Electronic Devices which accounted for 29.0 per cent of net sales. In descending order the other product divisions were Consumer Products (21.6 per cent), Wire and Cable, Metals, Chemicals and Other Products (17.6 per cent), Industrial Machinery and Plant (16.7 per cent) and Power Systems and Equipment (15.2 per cent). In 1986 Toshiba's net sales were 3.37 trillion yen (18.72 billion dollars). The most important product division was Industrial Electronics and Electronic Components (33 per cent of net sales), followed by Consumer Products (31 per cent), Heavy Electrical Apparatus (26 per cent), and Materials, Machinery and Other Products (10 per cent).