Major US food companies that sold products containing StarLink corn must now cough up US$9m after a federal judge ruled yesterday [Thursday] on a class-action lawsuit filed by consumers who claimed that the GM corn triggered several allergic reactions.

Kraft Foods, Kellogg Co, Azteca Foods, and Mission Foods have been told to spend US$6m on money-off coupons, which must be placed on their food products nationwide.

Judge James Moran, in the US District Court in Chicago, said that any money not redeemed through the coupons must be donated to a non-profit or charitable group that protects consumer interests. The companies are also liable for a US$3m charge for the administration of the program and lawyers' fees.

StarLink corn contains a protein that kills a major pest, the corn borer, but while it has been approved by the Environmental Protection Agency (EPA) for animal feed and industrial use, it must not be sold for human consumption. Contamination of conventional corn was quite widespread however, and some consumers complained of sickness after eating products with it in. Some experts believe that StarLink will still be contaminating the human food supply for another four to five years.

The lawsuit also includes Aventis SA's Aventis CropScience USA Holding Inc, which developed and marketed the corn but has now stopped licensing it, and the Garst Seed Co that sold seed contaminated with StarLink corn.

Farmers in some states are meanwhile still in the midst of another lawsuit against Aventis, claiming that their corn has lost significant value because of consumer concerns over the spread of StarLink.