Monsanto Co. has agreed to settle lawsuits by U.S. farmers who alleged they lost money after the company contaminated their wheat fields when a genetically modified strand was discovered in Oregon.

More than a dozen class actions resulted after a farmer made the discovery last year, prompting Japan and South Korea to immediately suspend imports of soft-white wheat from the United States. Grain futures prices also fell. The U.S. Department of Agriculture has not approved genetically modified wheat for commercial use.