The Advanced Display Manufacturers of America trade group has filed a complaint alleging dumping of flat-panel displays in the US by Toshiba Corp, Hitachi Ltd, Matsushita Electric Industrial Co, Seiko Epson Co, Sharp Corp, Mitsubishi Electric Corp, NEC Corp, Sony Corp and four other Japanese manufacturers, with Hoseiden Electronics Co, maker of the active matrix display on the Macintosh Portable, allegedly selling at a third of cost, highlighted as a particular offender: the complaint, lodged with the International Trade Commission and the Commerce Department, evidently covers all kinds of liquid crystal diode and other flat panels, and could lead to duties of 71% to 318% of the present prices being levied.