Monsanto Co. on Wednesday expanded its hunt for a technology to fight nematodes, tiny pests that cost U.S. soybean farmers alone more than $1 billion a year.

The Creve Coeur-based biotechnology company is paying an undisclosed amount for exclusive rights to evaluate a seed-coating technology developed by Plant Health Care Inc., a company established in Pittsburgh and registered in London.

If the technology known as Harpin succeeds, a product could be available to farmers by 2010, the companies said. If that happens, Plant Health Care will receive additional royalty payments.

“Nematodes are obviously pretty devastating pests for growers, both here in the United States and worldwide,” said Monsanto spokesman Lee Quarles. Advertisement

Monsanto also is partnering with other companies, including Creve Coeur-based Divergence Inc., to develop genetic modifications that could give soybean seeds protection against the soybean cyst nematode.

That technology could be commercialized in four to nine years, Quarles said.