Japanese and European antitrust authorities raided companies making cathode ray tubes on Thursday on suspicion of price-fixing.
Matsushita Electric Industrial spokesman Akira Kadota confirmed that Japan's Fair Trade Commission had begun a probe of its cathode ray tube unit, MT Picture Display.
Cathode ray tubes are used in television sets and computer monitors, although the market for them has shrunk with the advent of liquid crystal and plasma displays.
The European Commission said it had reason to believe that the companies concerned may have violated EC Treaty rules on cartels and restrictive business practices.
"The European Commission can confirm that on Nov. 8 Commission officials carried out unannounced inspections at the premises of manufacturers of cathode ray tubes," the Commission said in Brussels.
"The Commission has reason to believe that the companies concerned may have violated EC Treaty rules on cartels and restrictive business practices," it said.
Commission officials were accompanied by officials from the affected countries, it said.
Matsushita competes in the cathode ray tube market with Hong Kong-based LP Displays, formerly called LG Philips Displays, and with South Korea's Samsung SDI.
Samsung SDI said last month it may pull out of the cathode ray tube business if it continued to make losses.