Europe's competition watchdog Tuesday slapped a fine totalling 799.4 million euros ($1.1 billion) on the 11 airlines after finding they had coordinated pricing on their cargo business.
Cathay was told to pay 57.1 million euros.
The watchdog called the deal by the airlines -- including Air France-KLM, British Airways and Japan Airlines -- "deplorable" and "to the detriment of European businesses and European consumers".
It said the companies coordinated their action on surcharges for fuel and security without discounts over a six-year period, between December 1999 and February 2006.
Cathay said in a statement it was "reviewing the decision and evaluating its options with its legal advisers".
"Cathay Pacific remains committed to its long standing policy of full compliance with the law and reaffirms its support of full and fair competition among air carriers," it added.
A spokeswoman declined to confirm whether Cathay will file an appeal.
"We are reviewing our options, that's all we can say for now. We will update our shareholders and the stock exchange when we make a decision," she told AFP.
Cathay shares were trading 0.2 per cent lower on Wednesday morning at 22.05 Hong Kong dollars ($2.84).
The cartel covered flights from, to and within the European Economic Area.