WASHINGTON (AFP) - The United States said Thursday it was challenging some WTO findings over European subsidies to Airbus , in a transatlantic trade row over unfair state funding for commercial aircraft development. The US government appealed to the World Trade Organizations appellate body two findings in the panel report on European subsidies to Airbus , said Nefeterius McPherson, spokeswoman for the US Trade Representative. In a 1,200-page ruling made public in June on Washingtons complaint, the WTO asked European Union states to halt some aid for the development and export of Airbus airliners. The global trade body notably accepted three out of seven claims by Washington that key launch aid amounted to export subsidies which are illegal under WTO rules. The United States is challenging the WTO panels finding that the launch aid granted to Airbus over the course of 40 years was not part of an ongoing program of assistance, and finding that certain launch aid contracts were not export subsidies, McPherson said. She said the panel ruled in favor of the United States on most issues and we consider its reasoning sound. The June ruling was a very important victory for American aerospace workers and helped to level the competitive playing field for them, she said. However, the panel made two mistakes, and the United States is appealing these limited findings. The United States made its appeal in response to an appeal filed last month by the EU, which challenged most of the findings made by the panel. Last week the EU filed a 700-page brief in support of its appeal. The United States will file its response to the EU arguments at the end of September, McPherson said. Brussels said it would challenge the findings on export subsidies and on launch aid measures. It is also contesting the ruling that a causal link has been established between support to Airbus and adverse effects to Boeing. In addition, it is disputing the panels conclusion that infrastructure made available by EU member states to Airbus in Hamburg, Bremen in Germany and Toulouse in France amounted to illegal subsidies. This dispute is too important to allow the legal misinterpretations of the panel to go unchallenged, EU Trade Commissioner Karel De Gucht had said. What is more, not appealing would allow for an unhelpful precedent for the WTO membership as a whole, he added. Brussels pointed out that the case was not only unprecedented in factual but also legal complexity, and addressed issues that had not been previously settled in WTO case-law.