The 1,000-page final report, which was made public last week, reiterated the dispute panel verdict that the European Union's six-year moratorium on imports of genetically modified food and crops was illegal.
The panel also condemned the ban by six EU members - Austria, Belgium, France, Germany, Italy and Luxembourg - on a number of individual products previously approved by Brussels as safe.
But the ruling, which confirms an interim ruling published in February, does not tackle the thorny issue of whether GM foods are safe.
"The issues before the panel concerned the alleged failure of the European Communities to reach final decisions regarding the approval of biotech products from October 1998 to the time of establishment of the Panel on 29 August 2003, and the WTO-consistency of prohibitions imposed by certain EC member States with regard to specific biotech products after these products had been approved by the European Communities for Community-wide marketing," said the WTO.
"The panel did not examine whether biotech products in general are safe or not, or whether the biotech products at issue in this dispute are 'like' their conventional counterparts.
"Although this claim was made by the complaining parties the United States, Canada and Argentina - in relation to some aspects of their complaints, the panel did not find it necessary to address those aspects of the complaints."
Moreover, the panel did not question EU controls on imports of GM foods, or the right of countries to ban such foods on health or environmental grounds. The ruling will therefore not necessarily result in EU policy change.
The final ruling has been greeted by anti-GM campaigners as evidence that the WTO is the wrong place to deal with what they call 'environmental trade disputes'.
"The international community must find an alternative before another case occurs," said Sonja Meister, trade campaigner at Friends of the Earth Europe. "The WTO ignored international environmental laws, met in secret behind closed doors and barred any public involvement, even though we have a strong public resistance against GMOs in Europe."
Friends of the Earth suggested the International Court of Arbitration or the International Court of Justice as possible alternatives to the WTO to settle trade disputes over environmental matters.
But the biotech industry believes that the anti-GM lobby is being disingenuous. It argues that this case was never about the safety of GM food, but about the contravening of global trade rules.
"Environmental protection has never come into this discussion," said Simon Barber, director of the plant biotechnology unit at EuropaBio - the European association for bioindustries. "The only thing being challenged was the trade rules."
EuropaBio insists that the claims brought the US, Argentina and Canada were based on the ECs failure to implement regulations and procedures in a WTO consistent manner, which resulted in a violation of its WTO commitments.
These complaints were first made in May 2003. The United States (US), Canada and Argentina initiated cited an alleged de facto moratorium on approvals of biotechnology products, as well as the existence of individual Member State (Austria, Luxembourg and Italy) marketing and import prohibitions on previously approved biotechnology products.
These countries argued that the EU's de facto moratorium significantly harmed their export markets, particularly corn shipments, which typically include GM varieties.
The EU is the fourth largest market for US agricultural exports. According to the US department of agriculture (USDA), agricultural exports from the US to the EU are projected at $7 billion for 2005, nearly 12 per cent of all US agricultural exports.