USDA sued over genetically modified beet permits

* Suit claims USDA violated court order

* Sugar beets account for over half U.S. sugar supply

SAN FRANCISCO, Sept 9 (Reuters) - Groups opposed to genetically modified foods announced a lawsuit against the U.S. Department of Agriculture on Thursday over the agency's recent decision to allow limited plantings of altered sugar beets.

According to a copy of the complaint provided to Reuters by the plaintiffs, the USDA's decision violates an August court ruling that prohibited future plantings of genetically modified sugar beets. Last week, the USDA announced it would issue permits for seed producers to make plantings that would not be allowed to flower.

But the plaintiffs, which include the Center for Food Safety and the Sierra Club, argue in their lawsuit that these plantings could still contaminate neighboring crops. The complaint asks a judge to forbid the planting of any genetically modified sugar beet plants.

A USDA spokesman declined to comment, as did a representative of Monsanto Co (MON.N) , which is not a defendant in the lawsuit but is cited as a developer of genetically modified sugar beets.

The USDA has said it would take at least two years to develop new regulations in response to the overall ban issued last month by U.S. District Court Judge Jeffrey White, who sits in the Northern District of California in San Francisco. Sugar beets account for over half the U.S. sugar supply, but conventional beets remain widely available. [ID:nN01131347]

At issue are beets that are modified to resist a Monsanto herbicide, Roundup, which Monsanto sees as a way to improve crop yields and opponents see as driving evolution of dangerous weeds that overcome the herbicide treatment.

(Reporting by Dan Levine;editing by Sofina Mirza-Reid)

(dan.levine@thomsonreuters.com; + 415-348-4726)