After five years and thousands of gene-splicing experiements, a National Institutes of Health committee has taken what appears to be the first step toward ending federal regulation of genetic engineering.

Over the past two years the federal regulations on gene-splicing experiments have been loosened at each successive meeting of the NIH committee. Yesterday the group, the Recombinant DNA Advisory Committee, created a subcommittee to consider whether the regulations should be merely voluntary in the future.

Any researcher or institution receiving federal money for DNA work must follow NIH regulations. The prohibit outright some experiments with dangerous organisms, and demand special precautions for gene-splicing work with other organisms.

Failure to follow the regulations can be penalized by the loss of federal funds.

One reason the committee decided to form the subcommittee rather than make the regulations voluntary outright was public concern over genetic engineering.

The step to eliminate mandatory regulations would be "perceived in both the scientific and general public . . . as a massive relaxation of concern" about genetic engineering experiments, said Dr. Jean L. Harris, secretary of human resources for the state of Virginia and a member of the committee.

"There continues to be deep public distrust and concern about bioprocessing technologies," she said, as she recommended setting up a subcommittee rather than simply voting to make the regulations voluntary.

Patricia King, representing the Department of Justice on the committee, said, "There is no actual danger that we have been able to ascertain . . . the time has come to reasses the need for [mandatory regulations]. I think we're all in favor of deregulation; we only want to do it responsibly."

The experiments governed by the federal regulations are those in which the genes of one creature are spliced into the gene-set of another creature, where those genes then begin to operate.

The regulations came about in 1976 after biologists expressed worry over new organisms and new abilities of organisms they might create in the laboratory.

The NIH committee began the discussion with a proposal from biologists David Baltimore of the Massachusetts Institute of Technology and Allan Campbell of Stanford University. They suggested removing all punishments for failing to follow the regulations. They also recommended reducing the voluntary guidelines to the simplest form, in which all experiments except those with very hazardous bugs should be brought down to the lowest level of precautions.

The regulations now have four levels of precaution, leading up to specially built airtight rooms in which biologists must wear protective clothing and gas masks to work with the most hazardous organisms.

After 2 1/2 hours of deliberation, the committee voted 19 to 2 to study the proposal before acting on it. They also decided to solicit public comment on the proposal before final action.

A vote on whether finally to eliminate mandatory regulations is expected at the next committee meeting in September.