The process of writing a federal regulation is often fraught with delays and bloodied by the battles of adversaries, jousting over the issue at hand. A non-controversial rule change can take months, a controversial change years.

But now some people think there may be a better way: regulatory negotiation, or what one expert describes as the "hot tub" approach to writing federal rules.

Reduced to simple terms, says one report on the concept, it's as if everyone stripped off their adversarial clothing and jumped into trying to solve a problem with openness and honesty.

However, the author quickly noted, regulatory negotiations in reality would be far more complex. To start with, many parties would need considerable coaxing to take off their armor and dive in.

The report was prepared by Philip J. Harter for the Administrative Conference of the United States, a coordinating agency of federal officials and private attorneys that studies federal administrative and legal procedures.

Earlier this summer, the administrative conference voted to encourage federal agencies to use negotiations as an alternative to the traditional rule-making process. The concept also has sparked interest on Capitol Hill and in the Reagan administration.

In endorsing the concept, the conference noted that such negotiations have been used successfully in establishing standards with extensive health, safety and economic effects for thousands of products and in settling lawsuits that have challenged regulations.

One reason federal agencies have been reluctant to use negotiations in developing proposed rules, the conference suggested, is that so many controls have been placed on an agency's behavior.

The conference cited the so-called ex parte rules, which are designed to restrict the ability of federal officials to meet privately with one side of a dispute; the Freedom of Information Act, which permits public access to the rule-making record, and the Sunshine Act, which opens many agency meetings to the public.

The conference urged Congress to enact legislation that would free agencies in certain cases from ex parte restrictions and public disclosure requirements. This would "provide substantial flexibility for agencies to adapt negotiation techniques to the circumstances . . . ," said the recommendation. The legislation, it said, should be viewed as an experiment that would expire after a certain time unless renewed.

However, one member of the conference, Consumer Product Safety Commission member R. David Pittle strongly objected. The newsletter Inside OMB quoted Pittle as saying, "While open meetings with outside parties may be inappropriate in agency activities" such as the settlement of a lawsuit, "it seems essential in the development of rules that would affect a whole industry and the consumers of that industry's product."

Nan Aron of the Alliance for Justice, a coalition of public interest groups that has been critical of the rule-making process under the Reagan administration, agreed with Pittle. "The reason the guidelines are there," she said, "is to protect the public from business and agencies getting together to promulgate rules directly affecting the public without the public's participation."

Aron noted that public interest lawyers generally would rather negotiate settlements than have to go to court. But she said, "The evidence of the Reagan administration so far is that they're excluding the public" by limiting public comment periods and meeting with industry groups. "I would query whether they would actually be fair-minded and set up a situation where all sides could be heard."

The conference recognized that not all regulations can be developed through negotiations and in some cases a consensus process would be even slower than the current rule-making procedures.

Ideally, the conference said, the issue should be mature and ripe for a decision, and that a deadline should be set for issuing the rule. The issues selected also should not require any side to compromise its fundamental beliefs since it is unlikely that a consensus could be reached on such an issue. And all parties, it said, must believe they have something to gain from negotiations.

No party should dominate the negotiations, the conference added, not even the agency that will issue the rule. However, it said, the agency should not be forced to accept the outcome of the negotiations. Pittle was skeptical that these conditions would ever come together to allow negotiation of a significant rule. He said he could not "recall a single instance" during his nine years at the CPSC where all the conditions would have been met.

The conference's suggested procedures for regulatory negotiation are similar, in some ways, to the current rule-making process. Under the Administrative Procedure Act, which has been around since the New Deal, agencies are supposed to give notice that they are writing a new rule, seek public comments and analyze them before issuing a rule in final form. All steps along the way have minimum required time periods.

Under the conference's recommendation:

* Congress would authorize agencies to appoint a "convenor," a neutral party to organize the negotiations. It could be an individual, an agency or a private organization. If an agency employe is chosen, that person should not be associated with the rule-making or enforcement staffs.

* The convenor should decide whether negotiations are the proper way to proceed. The convenor should consider the factors outlined by the conference, as well as the effects a consensus decision could have on economic competition.

* If the convenor decides that negotiations would be appropriate, it should notify the agency. If the agency concurs, the convenor must decide on the participants, the scope and the work schedule.

* A notice should be printed in the Federal Register, and if additional groups ask to participate, a decision must be made by the convenor, in consultation with the agency.

* After agreement is reached, the agency will write the proposed rule, guided (but not bound by) the negotiating committee. The proposal will be available for public comment, and the comments can be reviewed by the committee.

* The final rule will be drawn up by the agency.