The U.S. Justice Department is investigating the possibility that Monsanto has been engaged in “anticompetitive conduct in the glyphosate industry.”

Glyphosate, the basic ingredient in Monsanto’s Roundup herbicide, became widely available through various generic labels soon after Monsanto’s glyphosate patent expired in 2000. Monsanto responded to increased competition by lowering the price of its Roundup products. But the company may also have sought to maintain customers by requiring farmers to use its brand of glyphosate on crops grown with Monsanto’s Roundup Ready seed. Using an off-brand of glyphosate on a Roundup Ready crop could void certain warranty protections from the company.

U.S. farmers have complained that glyphosate prices in Latin America, Australia and the Far East are substantially cheaper, nearly half the price paid by U.S. farmers in some cases, despite what appears to be fierce glyphosate competition between Monsanto and Syngenta in the U.S.

Monsanto spokesperson Lori Fisher said the company believes that the Justice Department has requested information from various glyphosate marketers and distributors and that Monsanto has cooperated with the government's “very broad-based” request for information.

“From our standpoint, we believe we've acted appropriately, and we are cooperating with their inquiry,” she said.

In December, Monsanto settled a lawsuit with Chemical Products Technologies and dropped its case against Zetachem of South Africa over technology used to make the generic version of Roundup. In 2001, Chemical Products had accused Monsanto of trying to thwart generic competition of Roundup.