SAN FRANCISCO, May 15 (Xinhua) -- U.S. top aircraft manufacturer Boeing Co. (Boeing) Tuesday called as "a landmark decision" a ruling by the World Trade Organization (WTO) determining that the European Union (EU) has provided billions of U.S. dollars in subsidies to European aircraft maker Airbus.

Boeing said the WTO has found that the EU has failed to honor multiple previous rulings and provided more than "22 billion dollars of illegal subsidies" to its business archrival Airbus.

"After examining this case for more than a decade, the WTO has determined the EU must end its unfair business practices and remedy the ongoing harm caused by the illegal subsidies," Boeing said.

The latest WTO ruling on the decade-old case, which was initiated in 2006, ends the dispute and clears the way for the United States Trade Representative (USTR) to seek remedies in the form of tariffs against European exports to the United States, Boeing said.

The United States has accused European governments of providing favorable loans to Airbus for its A380 superjumbo and the A350 long-range jet that compete with Boeing's 747 jumbo jet and 787 Dreamliner, respectively.

The United States can now take steps to establish the level of sanctions it can impose on European exports under WTO rules.

Boeing said the United States is expected to levy billions of retaliatory tariffs on the European exports, possibly the largest ever, which could come as early as 2019.

"Today's final ruling sends a clear message: disregard for the rules and illegal subsidies is not tolerated. The commercial success of products and services should be driven by their merits and not by market-distorting actions," said Dennis Muilenburg, Boeing chairman, president and CEO.