"It has been delayed a few weeks. I would not bank on anything before February," said one trade diplomat involved in the long-running dispute.

The United States, Canada and Argentina brought the case in May 2003, alleging that a five-year-old EU moratorium on approving imports of genetically modified (GMO) crops and food stuffs violated global trade rules.

The moratorium has since been lifted, but Washington and its allies say that imports are still heavily restricted, with a number of EU states refusing to accept any.

Europe's shoppers are known for their wariness towards GMO products, with some opinion polls indicating opposition of slightly over 70 percent.

But the United States, where the foods are far more widely accepted, says that EU scepticism has no basis in science and amounts to protectionism costing GMO producers hundreds of millions of dollars in lost sales.

The WTO panel of judges was set up in March 2004, with a ruling initially due within six months, but the deadlines have been continually extended.

Officially, the WTO judges have announced that a final ruling, which comes out some weeks after the preliminary finding, has been put back three months to the end of March, but it is the preliminary verdict that diplomats are watching, and no dates are officially announced for that.