Archer-Daniels-Midland Co. and Bunge Ltd., two of the largest U.S. grain traders, said they won’t accept a new variety of genetically-modified soybean being marketed by Monsanto Co. because it hasn’t been approved by the European Union and may put exports at risk.

Farmers have been asking ADM in recent weeks about Monsanto’s Roundup Ready 2 Xtend soybeans, Jackie Anderson, a spokeswoman for Chicago-based ADM, said in an e-mail Monday. Until it’s approved by all major export markets, including the EU, ADM “cannot accept it at our facilities,” she said. White Plains, New York-based Bunge posted signs at its facilities and notices on its website as of March 31 about its decision, according to spokeswoman Susan Burns.

“The wide-scale planting of traits that are not approved by key importing countries has the potential to seriously diminish the competitiveness of American grain and feed exports, and can result in damages throughout the entire agricultural supply chain,” Anderson said. “ADM’s policy is not to accept any commodity that contains a trait until it is approved in all of our major export markets.”

A letter from grain groups representing traders sent to St. Louis-based Monsanto on April 29 criticized the seed maker for selling its Roundup Ready 2 Xtend soybeans to farmers this season before receiving the green light from the EU, a major importer. The groups, which include the National Grain and Feed Association, North American Export Grain Association, National Oilseed Processors Association, said they had “grave concerns” that the export sector is at risk, and asked how the company planned to make sure the unapproved commodity won’t be commingled with approved supplies, according to the letter.

The grain groups in the letter also said they are concerned that Monsanto “has deviated dramatically from its previous prudent policy of securing U.S. export market approvals” before selling the seed in the country.