Harvey Heino has been selling residential real estate in Brooklyn for the last 15 years with few incidents. To hear him tell it, the former Wall Street clerk, who owns his own brokerage, is a thoroughly unremarkable member of his trade.

"We're not working for the buyer or the seller. The truth is, we're working for ourselves," Heino said of a real estate agent's approach to a sale. "We're trying to make a deal."

But if New York Secretary of State Gail S. Shaffer succeeds in pushing through a package of regulations that she tags a "consumer's bill of rights," Heino's view of who an agent represents would become so clearly illegal that he would either have to change his ways or lose his license.

Much of Shaffer's proposal restates existing laws, most significantly the centuries-old common law of agency, which defines agents' fiduciary responsibilities to their clients.

But key points in her package -- first circulated in draft form to the real estate industry for comment in December -- would drastically alter the way most residential real estate transactions are structured in New York, and they reflect issues being debated across the country.

Real estate trade groups such as the National Association of Realtors and the New York State Realtors Association oppose Shaffer's proposal, charging that she doesn't have the authority to hand down such far-reaching rules for the 180,000 real estate license holders her agency regulates, that she doesn't understand their business and that the rules would be a death knell to residential real estate sales in the state.

A state legislature oversight committee agreed, saying it was the legislature's job to make such rules, not Shaffer's. But the committee's word is not legally binding; Shaffer can issue the rules, and the real estate groups can challenge them at the agency level before taking their fight to a state court. A spokesman for the Realtors said the court challenge could come before the final draft is issued, expected sometime this year.

Shaffer's proposal would:

Require written disclosure to buyers of an agent's fiduciary responsibility to the seller. The Federal Trade Commission in 1983 concluded that 71 percent of all buyers assumed wrongly that the selling broker represented their interests.

Ban sub-agency relationships. Under current practice in New York and most other states, brokers who show properties listed by another broker on the Multiple Listing Service automatically act as sub-agents to that broker -- and they ultimately represent the seller.

Make dual-agency relationships clearly illegal. An agent would be barred from representing both the buyer and the seller in a transaction, since he can't serve both under the law of agency.

Make self-dealing illegal, because the agent cannot fulfill fiduciary duties to the client if he is seeking the best deal for his own interests, Shaffer said. The common example is that of a broker offering to buy the property he lists.

"Most of what we have here is current existing law that we are codifying," Shaffer said. "The industry has gotten away from these laws {of agency} to such a degree now that they don't even understand what is legal and illegal anymore... . The violations are so widespread, and not always even intentional. They truly do not understand in many cases what a fiduciary's responsibility is."

None of this sits well with broker Heino, who said he should not have to let the buyer know that he is representing the seller because the buyer "is not paying {my fee}, so why should it be explained?

"Why does it all have to be in black and white? There are certain chances {you take in life}," he said.

The New York State Association of Realtors, which represents about 25 percent of the state's real estate licensees, contends that agents like Heino are not the norm, and not members of the association.

In its fight against the proposed rules, the state group has the vigorous support of the National Association of Realtors, because the NAR recognizes that losing the fight in New York could mean similar losses in other states, said Robert D. Butters, NAR's deputy general counsel.

"If we believe that what happens in New York is not good public policy, we will encourage other states not to follow the same track," Butters said. "And we will work to change things in New York."

"These proposed regulations, if enacted and interpreted according to their plain meaning, will render invalid in New York generally accepted legal and ethical norms that govern the practice of real estate brokerage throughout the United States," wrote NAR's executive vice president, William D. North, in a letter to Shaffer.

Not everyone in the state's real estate industry shares the NAR's view. In New York and elsewhere, proponents of new ways of buying real estate, such as brokers representing buyers, are looking to regulations requiring disclosure of fiduciary duty and the abolishment of sub-agency to spur alternative arrangements.

James Arrow, a buyer's broker in Rochester, N.Y., has fought with tradition-minded agents in his market for years, and charges harassment and restraint of trade at the hands of agents who refuse to deal with alternative brokers.

Larry Outlaw, president of the Real Estate Educators Association and director of education and licensing for the North Carolina Real Estate Commission, said the NAR and state groups fear that a ban on sub-agency and a boom in buyer's brokerage will weaken their influence.

There is "concern that this could create more contentiousness {between real estate licensees} in real estate transactions by pitting one against the other," said Outlaw. "One other concern expressed by the real estate industry where these laws are proposed is that by requiring agency disclosure to prospective buyers, it will make prospective buyers more suspicious of other agents and perhaps hamper the smooth conduct of real estate transactions. A majority of prospective buyers do not realize that the agent represents the seller in a sub-agent capacity."

In Hawaii, where recent laws make sub-agency optional under the Multiple Listing Service, "approximately 90 percent of all listings there do not offer sub-agency," said Gail Lyons, a broker in Boulder, Colo., who gives seminars on agency relationships all over the country.

Lyons sees much of what Shaffer is proposing in New York as part of a movement that is slowly taking hold in the industry. "What appears to be happening nationally is a movement toward buyer-agency as opposed to sub-agency," she said.

In California, where fiduciary disclosure is now the law, 96 percent of buyers elect to go with a buyer's broker, Lyons said.

Amid all the debate, one of the few unworried brokers is Heino. "Me, scared?" he said. "No. I've been around too long. They can't pass most of this."