Monsanto shares plunged Friday as the US agriculture giant faced a rising protest over its genetically engineered seeds after an unapproved modified wheat strain was found on an Oregon farm. Two days after US officials announced the discovery of herbicide-resistant wheat on the farm, Japan suspended imports of US wheat, the European Union told its member states to test imports from the area, and South Korean millers said they would suspend purchases. That helped push Monsanto shares down 3.5 percent at $101.25 in late New York trade. The decline was much sharper than overall market losses. Shares had been relatively flat during the past 10 days, but remained up more than 7.0 percent in the year to date. The USDA said the wheat found in Oregon fields was the same strain as a genetically engineered or genetically modified, herbicide-resistant wheat tested by Monsanto between 1998 and 2005, but never approved. Monsanto, which says it ended the development of weed-resistant wheat nine years ago, has pledged to cooperate with the US Department of Agriculture investigation. While genetically engineered wheat is not approved for commercial sale anywhere in the world, other Monsanto GE products have drawn loud protests from consumers and environmental activists. On Friday, Monsanto said it was not pushing sales of GE seeds in Europe, where opposition is strong. \"We\'ve been telling people in Europe for the past several years that we\'re only going to sell biotech seeds where they enjoy broad farmer support, broad political support and a functioning regulatory system,\" Brandon Mitchener, a spokesman for Monsanto Europe, told AFP. \"These conditions apply only to a few countries in Europe today, primarily Spain and Portugal,\" he said. Monsanto sells its insect-resistant maize (corn) seed, labeled MON 810, in those two eurozone countries. \"We may continue to sell very small amounts of (GE) seeds to farmers who request them elsewhere, but we are no longer actively marketing them in most countries.\" He said the company also sells MON 810 to a farmer in Romania and several other in the Czech Republic and Slovakia.