The World Trade Organization has ruled that aircraft manufacturer Boeing received $3 billion to $4 billion in illegal subsidies in the form of federal research grants and local tax breaks, the top trade official said on Monday.

But Trade Representative Ron Kirk called the decision a tremendous victory for the United States because he said a separate WTO panel ruled last year that European governments provided $18 billion in subsidized funding for Airbus .

It is now clear that European subsidies to Airbus are far larger - by multiples - and far more distortive than anything that the United States does for Boeing, Kirk said in a statement.

The United States is ready to address all of the WTO findings, and we expect Europe to do the same. Airbus is a mature, highly capable company with ready access to commercial financing. It doesn't need the launch aid that European governments are continuing to provide, he added.

The WTO appellate body ruling on Monday faulted the United States for research funded by NASA and the Department of Defense that benefited Boeing and for tax breaks granted by the state of Washington and city of Wichita, Kansas.

The United States will have six months to comply with the ruling, once it is formally adopted this month, Kirk said.

(Reporting by Doug Palmer; Editing by Neil Stempleman)

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