The European commission has imposed the largest cartel fine in its history, imposing a €1.47bn (£1.2bn) penalty on seven firms including Philips, Samsung SDI and Panasonic for fixing the price of the now outmoded cathode ray tubes used in televisions and computer monitors.

For almost a decade between 1996 and 2006 the firms met in Paris, Rome, Glasgow and Asia for "green meetings", so called because they would often end in a round of golf. The companies fixed prices, shared markets, restricted output and allocated customers between themselves, on a worldwide basis.

Chunghwa, LG Electronics, Philips and Samsung SDI participated in both the television and computer screen cartels, while Panasonic, Toshiba, MTPD (currently a Panasonic subsidiary) and Technicolor (formerly Thomson) were members of only the TV syndicate.

Chunghwa, which blew the whistle, escaped a fine while others were given reductions in their penalties in exchange for co-operation.

Cathode rays are all but obsolete, with flat screens now the norm for televisions and computers, but at their peak, the commission said, the tubes represented between 50% and 70% of the price of a screen.

The competition commissioner, Joaquín Almunia, said: "These cartels for cathode ray tubes are textbook cartels: they feature all the worst kinds of anticompetitive behaviour that are strictly forbidden to companies doing business in Europe."