PLANO, Texas (AP) _ One of America's top snack makers is telling suppliers not to use genetically altered corn, angering farmers while pleasing some environmentalists.

Frito-Lay Inc. said the company was acting in response to consumers' worries. Spokeswoman Lynn Markley noted that the U.S. Food and Drug Administration has ruled that biotech foods are safe to eat, ``but we're a consumer products company.

``There is some consumer concern out there. We felt at this time it's appropriate to ask our growers not to sell us genetically altered corn.''

The American Farm Bureau Federation, which says biotechnology can produce larger and more nutritious crops, accused Frito-Lay of caving in to anti-biotech activists.

Frito-Lay executives ``are responding to small splinter groups out of fear they're going to be boycotted,'' said Joseph Fields, a spokesman for the farm group. ``We feel the companies are overreacting.''

Greenpeace and the Union of Concerned Scientists applauded the decision disclosed last week by Plano-based Frito-Lay, the leading U.S. maker of salty snacks. Greenpeace had lobbied Frito-Lay's parent company, PepsiCo., to stop using biotech crops in its products.

``Frito-Lay is about two-thirds of PepsiCo's sales,'' said Charles Margulis of Greenpeace. ``They realize the handwriting is on the wall and that people don't want to eat'' genetically modified food.

Last weekend in Montreal, United Nations talks produced complex rules governing trade in genetically engineered products, including language letting a country ban imports of a genetically modified product if officials feel there is a lack of scientific evidence proving its safety.

Markley the agreement would have no impact on the new policy.

The edict is contained in contracts Frito-Lay is sending to hundreds of its farmers. Last year, the company bought 1.2 billion pounds of corn, a tiny fraction of the U.S. crop, for products such as Doritos, Fritos and Tostitos chips.

Scientists create biotech crops by splicing the genes of plants and inserting genetic material from other organisms to make the original bigger, hardier or tastier.

Farm groups argue that genetically altered crops use less pesticide. Critics say weeds and pests would eventually adapt, requiring stronger and more environmentally dangerous weapons to kill them.

According to the U.S. Agriculture Department, more than half the soybeans and cotton and about one-third of the corn grown in the United States last year used gene-spliced seeds. Potatoes and tomatoes are also grown the same way.

Frito-Lay's action follows last summer's announcement by Gerber and Heinz that they would stop using genetically modified ingredients in baby food even though they believe the ingredients are safe.