The European Court of Justice ruled on Wednesday against a group of U.S. airlines that challenged a European law requiring that all airlines flying to and from EU airports to buy permits under its emission trading scheme from January 1.

The scheme is aimed at helping offset the carbon emissions of European flights.

"We deeply regretted that the United States lost the lawsuit. China will continue to steadfastly pursue a lawsuit," Chai Haibo, deputy secretary of China Air Transport Association CATA.L, was quoted by the Economic Observer for its Monday edition as saying.

China Daily on Friday also quoted Chai as saying that China's four major state-run airlines have reached an agreement with CATA to jointly sue the EU in Germany at the end of this month.

"We know that the prospect of victory is dim, but we want to show our firm opposition by launching a lawsuit," Chai was quoted by China Daily as saying.

CATA was told by the industry warthog, the General Administration of Civil Aviation of China CAAC.L, to act with a unified voice on behalf of the main airlines, the Economic Observer said, citing an industry executive.

CATA says the scheme will cost Chinese airlines 800 million yuan in 2012 and more than triple that by 2020.

The case before the Wednesday ruling by the EU's highest court has triggered hostile reaction from airlines around the world, as well as blocking legislation in the U.S. Congress and a threat from U.S. Secretary of State Hillary Clinton.

(Reporting by Chen Aizhu; Editing by Yoko Nishikawa)

• A Permanent Economic Emergency