The European Commission has fined six LCD panel makers €649m (£543m) in total for price fixing but handed Samsung immunity as it ratted on the others.
The governing body said Samsung, LG, AU Optronics, Chimei InnoLux, Chungwha Picture Tubes and HannStar operated a cartel between October 2001 and February 2006, agreeing price ranges.
"The companies concerned knew they were breaking competition rules and took steps to conceal their illegal behaviour," said Joaquin Almunia, EC VP of the competition policy.
Over a four-year period the cartel met at 60 'Crystal Meetings' in Taiwanese hotels. There they set minimum prices and shared information on production forecasts, factory utilisation and other commercial terms.
This impacted Europe as the vast majority of LCD panels used in televisions, PC displays and mobile phones were produced by the six firms in the Far East.
The EC considered sales volumes, the nature of the crime and its duration when setting fines; Chimei InnoLux had to pay €300m, LG €215m, AU Optronics €116.8m, while Chungwha and HannStar coughed up €9m and €8m respectively.
Whistleblower Samsung "received full immunity" under the EC's 2002 Leniency Notice, while LG, AU and Chungwha's fines were also reduced due to cooperation.
"The only understanding we will show is for those that come forward to denounce a cartel and help to prove its existence," said the Almunia at the EC.
Earlier this year, Dell filed a lawsuit in the US alleging that Sharp, Hitachi, Toshiba, Seiko Epson and HannStar colluded to set LCD panel prices artificially high. The case has yet to be heard.