Lynn Swann, the Republican candidate for governor, defended his proposal to revamp the state property tax system yesterday before one of the groups that would be most affected by it, a roomful of real estate professionals.

Mr. Swann argued that his plan would help the real estate market and make buying decisions easier by making taxes more predictable. He also noted that his plan, unlike several competing concepts before the Legislature, does not rely on revenue from an increase in realty transfer taxes.

In interviews afterward, several Realtors offered polite but cautious responses to the Republican's pitch. A common reaction among those questioned was skepticism, not so much toward Mr. Swann's plan in particular, but toward Pennsylvania's decades-long debate on the general subject of real estate tax reform.

Mr. Swann's plan, sketched out in a speech earlier this week, would combine a shorter-term package of property tax relief to homeowners with a longer-range change in the assessment system underlying the property tax.

Mr. Swann would replace the current valuation estimates with a fixed figure based on the actual purchase price of a home. Whatever the dynamics of the local real estate market, that figure would not change until a property was again sold.

A spokesman for Mr. Swann's Democratic opponent, Gov. Ed Rendell, warned that the challenger's plan would hurt state educational standards by starving school districts of revenue.

"Realtors and every Pennsylvanian ought to be afraid of any plan based on California's Proposition 13,'' said Dan Fee, Mr. Rendell's campaign press secretary. "Imagine how hard it is going to be to sell a home if the local school is awful.''

Ray Zaborney, Mr. Swann's campaign manager, disputed that contention, arguing that the proposal was designed to curb increases in real estate revenues without rolling them back so steeply as under the landmark California initiative.

"We've learned from the mistakes of Proposition 13," Mr. Zaborney said.

In his speech to several hundred people at the David L. Lawrence Convention Center, Mr. Swann said, "Realtors should not be concerned about the impact on home sales under the Swann plan." He noted that the California real estate market has boomed in the years since Proposition 13 passed.

Mr. Swann criticized a variety of other current proposals for property tax relief, including the bill supported by the Rendell administration that stalled in the House before the primary election. He also questioned a more sweeping plan advanced by some Republicans, which would dramatically lower property taxes while replacing its revenue with an increase in the sales tax rate.

"If you try to do it by raising the sales tax, what you're really doing is creating new winners and new losers,'' he said.

Mr. Swann's plan rests in part on cost savings envisioned from a proposed amalgamation of health care purchasing among all of the state's school districts. While it's not part of his property tax plan, he said in response to a question that there's no reason such a consolidated purchasing approach could not be extended to municipal employee health care throughout the state.

Leaving the meeting, one Realtor, Jan Palmer, said she was pleased that Mr. Swann said he would not increase the transfer tax, but said, "The real thing I would like to see is to get rid of the property tax altogether and replace it with the sales tax.''

Another, Joe Volpe, said, "I'm an issues person. I want to look more at the details. I'm going to check it out on his Web site. But, you know, this is something that all of these politicians have been talking about for how long? Thirty years?''

Scott Waitlevertch, senior vice president of public affairs for the Realtors Association of Metropolitan Pittsburgh, said the group was not ready to endorse any of the plans percolating through the Legislature and the campaign.

"Some of the ideas are interesting and of course some of them have been floating around for 30 years, so we have to see how they fit together,'' he said. "The effect on new home buyers is one concern, but we have to run the numbers and assess this alongside the other plans."