NEW YORK, July 6 (Reuters) - ConAgra Foods Inc. misled the public by labeling its popular line of Wesson cooking oils "100% Natural" and "Pure," despite the fact they were derived from genetically modified plants and organisms, according to lawsuits filed in New York and California.

The two class-action suits, filed separately in federal court in Los Angeles and Brooklyn, seek millions of dollars in refunds on behalf of recent purchasers of ConAgra's Wesson oil line -- including canola oil, vegetable oil, corn oil and a blend -- as well as a court order prohibiting the company from making its all-natural claim on Wesson oils.

According to the complaints, ConAgra is unable to support its claim that its oils are "100% natural" because they contain ingredients made from "unnatural" genetically modified plants, defined by the World Health Organization as "organisms in which the genetic material has been altered in a way that does not occur naturally."

ConAgra "engaged in this misleading and deceptive campaign to charge a premium and take away market share from other similar products," according to the Brooklyn complaint.

ConAgra said in a statement, "We don't comment on pending litigation, but we don't believe the case has merit and we stand behind our labeling."

The Wesson website makes no mention of the origin of the products used to make the oils, according to the Los Angeles lawsuit. But buried on the ConAgra corporate website, the plaintiffs alleged, is the indirect admission that it uses bioengineered ingredients in many of its food products, including Wesson oils.

The ConAgra website states, "Both the U.S. Environmental Protection Agency and the FDA have concluded that biotech foods that are approved for human consumption are as safe and nutritious as other foods that are developed through more conventional methods."

The site goes on to say, "We will continue to listen carefully to our customers and consumers about biotechnology and provide alternatives for those who demand products without biotechnology ingredients."

The Los Angeles lawsuit seeks certification of a class comprising all Wesson oil purchasers since 2007. It estimates the amount sought in refunds to be more than $5 million. The New York lawsuit was brought on behalf of all Wesson purchasers since June 2007 and does not specify an amount of damages.

The New York case is McFadden et al v. ConAgra Foods Inc., in the U.S. District Court for the Eastern District of New York, no. 11-3186. The California case is Briseno et al v. ConAgra Foods Inc., in the U.S. District Court for the Central District of California, no. 11-5379.

For the New York plaintiffs: Kim Richman and Michael Reese of Reese Richman.

For the California plaintiffs: Jeff Westerman, Andrei Rado and Jessica Sleater of Milberg.

(Reporting by Jessica Dye)