The authority cited a decision of an arbitration board based in Miami which it said was released earlier on Friday.
The consortium GUPC, which includes Sacyr SA of Spain and Impregilo International Infrastructures NV of Italy, no longer exists. After hours on Friday, neither company could be contacted for comment.
The lawsuit, initiated in 2015, concentrated on disputed cost overruns dealing primarily with concrete quality. It marks the latest of three verdicts of arbitration resulting from the expansion of the canal, completed four years ago and enabling the canal to handle larger ships.
There are currently two court rulings addressing separate disputes between the canal authority and the GUPC.
Maritime Business World