Taking a long-awaited stand in an emotionally fraught food fight, the Food and Drug Administration yesterday released a 678-page analysis concluding that milk and meat from cloned animals pose no unique risks to consumers.

The decision, subject to change after a period of public comment, stops short of approving the sale of food from clones and leaves in place for now a long-standing government request that farmers keep their clones off the market.

But it represents a crucial milestone for the handful of biotechnology companies that see cloning as a welcome opportunity to sidestep the vagaries of sexual reproduction and instead mass-produce some of the nation's finest meat- and milk-producing animals.

"The higher-end breeders are going to start signing up and taking advantage of this," said Mark Walton, president of Austin-based ViaGen, which has produced about 250 cloned cattle and pigs in preparation for what the company hopes will be a robust market in farm clones. "They've been interested, but they've been skeptical that we'd ever get the regulatory process dealt with."

Opponents, however -- including some who doubt the safety of cloned food and others concerned about the welfare of the animals -- vowed to fight the new momentum toward approval.

"This is a lose-lose decision for consumers and the dairy industry," said Joseph Mendelson, legal director at the Center for Food Safety in Washington, which has petitioned the FDA to regulate cloned farm animals one type at a time, much as it regulates new drugs.

Release of the draft risk assessment was delayed for years, in part by a coalition of big-name dairy companies concerned that the "yuck factor" surrounding cloned animals might tarnish milk's image and undermine sales. Surveys have consistently found that a majority of consumers are wary of food from clones, with many saying they would avoid it.

Yet study after study reviewed by the FDA failed to find any scientific reason to keep meat or milk from clones off store shelves.

"Extensive evaluation of the available data has not identified any food consumption risks or subtle hazards in healthy clones of cattle, swine, or goats," the FDA risk assessment concludes.

In apparent recognition of consumer distrust of cloned food -- and of widespread public misunderstanding about the science of cloning -- the agency posted on its Web site not only the detailed technical report but also several lay-language documents that aim to debunk negative "myths" about clones, which the agency notes are copies of existing animals and are not engineered to have new traits.

The agency also took the unprecedented step of posting all the raw scientific data it used to come to its conclusion, along with unedited copies of comments it received from independent experts who were asked to review the report in advance.

"We have looked very, very closely," Stephen F. Sundlof, the FDA's chief of veterinary medicine, said in a telephone news conference. "There's just not anything there that is conceivably hazardous to the public health."