Washington ? U.S. farmers could lose overseas clients if genetically engineered wheat pollinates with other crops, say farm and consumer groups who want the government to suspend the development of the biotech grain.

In a petition filed Tuesday with the Agriculture Department, the groups said wheat genetically designed to tolerate a widely used herbicide could lead to grain mix-ups in the field and in shipments, making some exports unacceptable to trading partners.

Monsanto Co., the St. Louis biotech company that manufactures the Roundup herbicide, is developing a variety of hard red spring wheat that would withstand its popular weed-killer.

The petitioners want the government to determine the impact the new variety of wheat would have on exports before allowing its development to continue.

Joseph Mendelson, legal director for the Center for Food Safety, an anti-biotech group and one of the petitioners, said he worries the company wants to rush the wheat to the market to rebound from recent financial troubles.

“Our fear very much is given that this is a major product for Monsanto, and given that the company in general has not been very favorable to… Wall Street lately, that (Monsanto) will push very hard to get this out onto the market,” he said.

Monsanto said last month it lost $1.69 billion, or $6.45 per share, in 2002. In December, longtime president and CEO Hendrik A. Verfaillie resigned, citing the company’s poor financial performance .

Other petitioners included the Western Organization of Research Councils, the Dakota Resources Council, Northern Plains Resource Council, Northern Plains Sustainable Agriculture and the Family Farm Coalition.

Agriculture Department spokesman Ed Curlett said officials were reviewing the petition and had no comment.

The agency is required to determine the impact a new biotech plant could have on the environment before a company can register it for sale.

The wheat is years away from being ready for the market, said Michael Doane, a Monsanto wheat official. The company filed information about it for the government to begin reviewing at the end of last year.

Doane said the company believes the wheat is safe for growing and eating.

“We feel like we’ve submitted a very strong package that will support registration,” Doane said.