The Fair Trade Commission has raided Canon Inc. on suspicion that the camera and printer company is unfairly obstructing the sale of laser-beam printer toner cartridges produced by other firms for use in Canon products,

The FTC searched Canon's Tokyo headquarters Thursday. The firm allegedly tried to shut out other vendors through such measures as frequently changing the cartridge specifications of new color laser printers for office use.

Canon sells house-brand cartridges for use in its laser printers, but more than 10 other companies sell new generic cartridges and refilled Canon cartridges that can be used in Canon printers.

Laser-beam printer toner cartridges sell for between 20,000 yen and 40,000 yen per unit. An increasing number of vendors have begun to recycle used cartridges produced by Canon and other major printer makers for secondary sale.

The vendors offer the recycled products at prices half that of major printer makers', hurting their cartridge businesses.

Canon is the biggest Japanese maker of laser-beam printers for personal computers, commanding a 60 percent share of the market.