The European Shippers' Council says the recent use of bunker surcharges amounts to "price signaling" by the major container lines.
As such, it violates terms of the agreements the liners made to the European Commission.
The ESC made its views known in a letter to Margrethe Vestager, the European Commission's anti-competition chief.
It said the bunker surcharges were implemented despite oil prices being on the rise generally, and not due to an unexpected events.
