The World Trade Organization ruled on Friday that billions of dollars in European loans to help Airbus develop civilian aircraft are an illegal subsidy under world trade rules, a person familiar with case said.

The source, who spoke on condition that he not be identified, said the decision was a big win for the United States, but should not be a surprise to either side.

I don't think people are shocked that launch aid is deemed to be an inconsistent subsidy. I think the shock would have been if the U.S. had lost, he said.

(Reporting by Doug Palmer; editing by Jackie Frank)