"My guess is it's going to take two or three years to get regulatory approval," Grant said.

Monsanto wants government approval of a herbicide-tolerant biotech wheat hybrid. The Roundup Ready wheat, which could be commercially available within two years, would be the first biotech wheat in the world.

Even if Monsanto wins government approval, company officials have insisted it would not market biotech wheat until growers and consumers were comfortable with it.

Several major importers, including Japanese and South Korean flour millers, have expressed concerns about biotech wheat and have warned the U.S. industry that if it is approved in the United States, they would buy elsewhere.

Monsanto first applied for Bush administration approval of Roundup Ready one year ago. The U.S. Department of Agriculture is still reviewing the application for completeness.

Grant said it was unclear when Monsanto would seek approval from Japan - the biggest export market for U.S. wheat - for its biotech wheat.

Grant spoke to reporters after addressing an agricultural conference sponsored by Farm Journal.

American farmers have been enthusiastic about other genetically modified crops that Monsanto has produced, he said, with a satisfaction rate of about 95 percent or higher. "Wheat, I think, will beat that," Grant said, because it produces cleaner and higher quality grain.

Given European resistance to gene-spliced food, Grant said Monsanto did not expect to sell biotech seed in Europe "anytime soon."