(NaturalNews) Chemical and agricultural giant DuPont has accused rival Monsanto of maintaining a seed monopoly, in a complaint filed with the U.S. Departments of Justice and Agriculture.

"Monsanto has engaged in numerous practices that improperly seek to expand the scope of intellectual property rights at the expense of competition, innovation, and choice," the 18-page DuPont report reads.

DuPont, which owns the genetically modified seed company Pioneer Hi-Bred International, is Monsanto's main competitor in the agricultural biotech field. The two companies are already in court over a failed licensing deal.

The complaint alleges that Monsanto controls 98 percent of the U.S. market in soybeans, 79 percent of the market in corn and 60 percent of the market in patented soy and corn genetics. It accuses the company of using coercive tactics to rope farmers and seed dealers into agreements that make them dependent on its patented and expensive products.

"The ag biotech trait market is firmly in the grip of a single supplier, acting as a bottleneck to competition and choice... it also threatens the global goals for agriculture in the 21st Century doubling the world's food supply by 2050," the report reads.

Monsanto has been accused of many of the same practices by biotechnology critics, who allege that Monsanto's herbicide-resistant crops increase reliance on Monsanto chemicals and point to the company's aggressive prosecution of farmers who save and replant Monsanto seed. The company has also been known to sue farmers whose crops become genetically contaminated through cross-pollination with Monsanto-modified crops.

Although biotech critics tend to single out Monsanto as the world's largest supplier of genetically modified seed, they also level many of the same criticisms at DuPont, Bayer, and other biotech companies. Big seed companies in general have come under fire for encouraging farmers to plant expensive modern hybrids over native varieties, thus reducing seed diversity and exposing the world to a greater risk of food shortage.

The DuPont complaint comes ahead of five planned Department of Justice and Agriculture hearings into concerns about competition and monopoly in the agricultural marketing sector