A French court upheld on Thursday a 2012 ruling in which Monsanto was found to be liable in the chemical poisoning of a French farmer, who says he suffered neurological problems after inhaling the U.S. company's Lasso weedkiller.

The decision by an appeal court in Lyon, southeast France, confirmed the initial judgment, the first such case heard in court in France, that ruled Monsanto was "responsible" for the intoxication and ordered the company to "fully compensate" grain grower Paul Francois.

Monsanto's lawyer said the U.S. biotech company would now take the case to France's highest appeal court.

Francois, who says he suffered memory loss, headaches and stammering after inhaling Monsanto's Lasso in 2004, blames the agri-business giant for not providing adequate warnings on the product label.