The CJEU, Europe's highest court, rejected a complaint from Pilkington about the sales figures and exchange rate used to calculate the fine.
The European Commission imposed the fine on Pilkington in 2008, when it found the company guilty of price fixing in the market for car glass between 1998 and 2002.
The fine calculation included contracts that were negotiated before the cartel was in place, Pilkington said. The glassmaker also said that the exchange rate used to convert its sterling-based sales figures into euros had cost it an extra €40 million.
CJEU advocate general Juliane Kolkott said that the whole turnover achieved should be used to calculate a fine when the object of a cartel is to distort competition. To use only some sales figures would "artificially reduce the economic effect of the cartel" and would also involve a disproportionate effort by the court, she said.
On the exchange rate, Pilkington argued that the Commission should have used the European Central Bank exchange rate on the day it made the decision rather than an average for the previous year. Kolkott said that this would have been "comparing apples and pears", applying a new exchange rate to old figures. The average rate "reflects the economic realities" over the course of the year, she said.
A further appeal concerning the automotive glass cartel is currently pending before the CJEU. However, it does not challenge the same judgment of the General Court and raises entirely different legal issues, the CJEU said.