WASHINGTON - A U.S. appeals court will hear arguments next month in the latest bid by a persistent American ranchers group to restrict Canadian cattle imports.

The case, pursued for years by the Ranchers-Cattlemen Action Legal Fund, or R-CALF, will get yet another airing July 13 in Portland, in the Ninth Circuit Court of Appeals.

The Montana-based group's legal fight was successful in delaying the beef trade after Canada's first mad cow case in May 2003, prolonging a crisis that has cost Canadian ranchers billions.

Since then, trade has resumed in younger cows thought to be at a lower risk for contracting the deadly disease.

But R-CALF is still fighting for a total ban, even as the U.S. government works on a new rule to reopen the border to older cattle and beef products.

The group argues Canadian imports are unsafe and U.S. officials are endangering the food supply.

Many industry observers say they think R-CALF is just wasting everyone's time by appealing to a court that's already turned them down once.

But some here are perplexed that the appeals court hasn't stopped the process long before now.

And they're bracing for any fallout from the hearing at a time when Canada and the United States are still trying to convince some countries that North American products are safe.

"Once again, it puts the industry's fate not in the hands of those who know, nurture and prosper by it, but in the hands of the judicial system," said Steve Dittmer, executive vice-president of the Agribusiness Freedom Foundation, a group that promotes free trade.

"It holds the potential for virtually no good and tremendous harm and destruction on top of that already caused."

R-CALF spokeswoman Shae Dodson said the group was unaware the hearing had been set and needed more time before commenting.

Last month, Canada and the United States got good marks on beef safety from the Paris-based World Organization for Animal Health.

They both received a "controlled risk" designation, the second-highest safety label.

But Mexico and Japan, two other top beef markets, still have some restrictions on Canadian imports.

Meanwhile, R-CALF has been rocked of late by internal dissension about whether endless lawsuits or lobbying is the most effective way to go in trying to reduce imports.

The group originally won a temporary injunction against Canadian imports in a Montana district court.

But that decision was overturned by a three-judge panel at the appeals court in 2005, paving the way for some trade to resume.

Now R-CALF wants the same appeals court to instruct the same district judge, Richard Cebull, to hear the case for a permanent injunction.

Canada submitted a brief in the case in March, saying the country's beef safeguards are highly effective in protecting against disease.

There have been 10 cases of mad cow or bovine spongiform encephalopathy (BSE) in Canada and two south of the border.