The Fairfax Board of Supervisors adopted a controversial zoning plan yesterday that will enable a private developer to build a new county government center at his expense in exchange for up to 146 acres of prime county-owned land.

The board's 6-to-0 vote authorized private-sector development on 216 acres of property formerly reserved for government use. Residents at the meeting argued that the county was acting hastily and ignoring the impact of greater density on roads and other public services in the Fair Oaks area, where the new center would be built.

The vote allows the county to proceed with a plan to move its offices out of congested Fairfax City to a 183-acre site just south of Fair Oaks Mall near Rtes. I-66 and 50.

Under the plan, which was first proposed by County Executive J. Hamilton Lambert and approved by the board in concept last December, the county will select a developer to build the new center. In return, the county will give the developer up to 113 acres at the site for private development. As an additional incentive for potential developers, the county plans to throw into the deal 33 more acres of county land, now being used as a park, on a nearby tract at I-66 and West Ox Road.

Yesterday's vote, which changed the zoning of the property, does not commit the county to the joint venture arrangement between itself and a developer nor does it set the exact amount of county-owned property the developer would receive.

The county has advertised the proposed arrangement nationally and is awaiting proposals from developers before making a final decision on whether to proceed with the plan. The board is expected to select a developer for the project sometime this summer.

The zoning change, however, provides a clear signal of the board's support for Lambert's proposal, prompting severe criticism from several civic leaders attending yesterday's meeting.

Thomas B. White, president of the Fairfax County Federation of Citizens Associations, said the board was cutting residents out of the decision-making process by rezoning the land before deciding how to develop it. He characterized the proposed land swap as "a very dangerous approach," saying the county was preparing to surrender valuable land that it should instead be selling on the open market.

Dan W. Funkhouser, president of a civic group comprising residents living adjacent to the proposed government center site, said county officials misled those residents in the last several years when it left the development of homes, offices and businesses out of its discussions on the new center.

"When we supported the idea of a government center, we did not understand, nor did we look forward to, the kind of density you're now proposing," Funkhouser told the supervisors.

Board Chairman John F. Herrity countered that the joint venture "makes good business sense." He said it relieves county residents of the burden of financing the government center through a bond issue. Herrity told the plan's critics that he "has no intent to go into debt to build offices for bureaucrats."

Lambert, responding to the complaints that the county would come out on the short end of the deal, said Fairfax officials would be careful to determine the current market value of the property before agreeing to trade it.

Supervisor Audrey Moore (D-Annandale), who has expressed serious doubts about the county's ability to bargain effectively with developers, was sick yesterday and did not attend the meeting.

Estimates range from $50 million to $70 million on the value of the prime county land that would be turned over to the developer selected to be part of the joint venture.

The county has been pondering a potential transfer of its government offices since the late 1970s because of increasingly crowded conditions at the Massey Building, which now houses the bulk of the county government offices. The building has inadequate parking and county residents must drive through traffic-clogged Fairfax City to reach it.

Moving into its own facility also would relieve the county of the estimated $5 million yearly rent it pays Fairfax City for use of the Massey Building, according to board members.