The National Park Service has been accused in a lawsuit of illegally selling off federal resources in secret contracts with biotech researchers who want to patent microbes from Yellowstone's hot springs.

"The Park Service cut a backroom deal and bent laws to allow the commercial exploitation of Yellowstone," said Joseph Men-del-son, a lawyer for one of the plaintiffs. They argue that U.S. law prohibits any natural resources - from minerals to pine cones - from being removed from national parks."The precedent set by this agreement threatens not only Yellowstone but all of our parks," said Mendelson, of the International Center for Technology Assessment, a public interest group based here.

The Alliance for the Wild Rockies of Missoula, Mont., and the Edmonds Institute of Edmonds, Wash., joined in the lawsuit filed in U.S. District Court here Thursday. The suit seeks to block pending contracts with Diversa Corp. of San Diego.

The deal could be worth millions of dollars to Diversa, but to date the Park Service has refused to disclose what kind of royalties the federal government would receive as a result of the so-called bio-prospecting for patents on the tiny organisms in the rare thermal pools.

Another company already is profiting from a Yellowstone-derived enzyme extracted in the 1960s and now widely used in DNA fingerprinting, the suit said.

"In order to pry open the deal-making decisions for public scrutiny and involvement as well as to ensure environmental impact assessment, we find it necessary to take the whole process to court," said Beth Burrows of the Edmonds Institute. The public interest group in the Seattle area focuses on public health, ecosystems and modern biotechnologies.

A spokeswoman for Diversa, Linda Seaton, said the company had no comment. "You should talk to the people at the National Park Service and the Interior Department," she said. "It really involves them and not Diversa."

Park Service spokeswoman Jackie Handly said the agency had not seen the lawsuit and had no response.

Enzymes, the proteins that operate cells, typically break down at high temperatures. But the microbes in Yellowstone's springs and geysers apparently are more durable because they have evolved in the near-boiling water.

The Park Service has acknowledged that under the agreement, Diversa would pay Yellowstone $100,000 over the next five years and donate $75,000 worth of in-kind services.

But the service has refused requests filed under the Freedom of Information Act regarding the percentage of royalties that would go to the government, saying that information falls under the category of a proprietary trade secret.