Genetic engineering using recombinant DNA techniques poses no greater risk than selective breeding or other methods of altering organisms, the National Academy of Sciences reported yesterday.

The report recommended that genetic engineering be regulated on the basis of the organism and the environment into which it will be introduced, rather than the process by which it was produced.

"There is no evidence that unique hazards exist either in the use of {recombinant-DNA} techniques or in the movement of genes between unrelated organisms," the report said. " . . . R-DNA techniques constitute a powerful and safe new means for the modification of organisms," it added.

The technique of altering plants or bacteria by changing their genetic material, or DNA, has prompted fear that subsequently releasing them into the environment could lead to uncontrolled spread of dangerous organisms.

While organisms have long been altered by selective breeding or chemical treatment, recombinant DNA techniques have been considered more threatening.

The concern was underscored last week when, without authorization, a Montana State University professor injected genetically engineered microbes into 14 elm trees, hoping to combat the Dutch Elm fungus. Gary Strobel, a professor of plant pathology, said he violated federal regulations as an act of "civil disobedience."

A spokeswoman for the Environmental Protection Agency (EPA), which is considering sanctions against Strobel, said the agency will not change its plans because of the academy's report.

A panel of five scientists conducted an eight-month study for the academy, the nation's most prestigious organization of scientists and engineers.

"Our main purpose was to reassure the public at large that some of the scenarios that have been postulated -- that organisms basically considered to be benign would be converted to threatening pathogens -- would not be, based on the biological evidence we have," said panel Chairman Arthur Kelman, professor of plant pathology and bacteriology at the University of Wisconsin.

The report was criticized by Jeremy Rifkin of the Washington-based Foundation on Economic Trends, who has been vocal in his warnings about genetic engineering.

The report, he said, "reflects the Reagan administration position that commercial profits come first and the environment comes second. It's so out of line with much of the information collected over the years."

Kelman said the administration had not influenced the panel.

He said the group recommended that rules about altered organisms be restructured according to "categories of risks" rather than a system that treats all genetically engineered organisms as dangerous.

"We're not saying there are no risks," he said. "We recognize there may be some risks, but they're not all at the same level as the introduction of a destructive plant pathogen."

Release of genetically engineered organisms is regulated by several federal agencies, including the EPA and the Food and Drug Administration. "At the moment, most regulatory agencies are very conservative," Kelman said.

Representatives of the biotechnology industry, which has been lobbying for less restrictive regulations, praised the report.

"We've been saying this all along and urging that various regulatory agencies regulate the product and not the process," said Richard D. Godown, president of the Industrial Biotechnology Association.

Andrew Dobson, a professor of biology at the University of Rochester who reviewed a draft version of the report for the Ecological Society of America, said, "It's fairly sensible. It's got a certain amount of ambiguity in it, but you've got to have a certain amount of flexibility."