The Fairfax County Board of Supervisors signaled its support late last night for a citizens-backed report that cautions against excessive office and commercial development in rural Centreville.

The board voted 4 to 3 to accept the report's broad zoning outlines for Centreville but postponed adoption 30 days.

The decision was a defeat for some of the area's largest developers, including John T. (Til) Hazel, who urged that the report be rejected and replaced with their proposal that would nearly double the density suggested by the citizens study and provide for predominantly office-commercial construction.

Republican Board Chairman John F. Herrity and Supervisor Elaine N. McConnell (R-Springfield) urged adoption of the report last night but refused to support the move to accept it in principle pending a 30-day delay for minor modifications. They said they wanted to accept the report unequivocally.

Harold Dodson, an outspoken advocate of the report, said after the meeting that he believed that Herrity and McConnell were speaking publicly for the report while trying privately to undermine it, and he accused them of "political posturing."

McConnell, whose district includes Centreville, has been embroiled in a dispute with residents for a month. After initially indicating her support for their plan, she said that it lacked an adequate road funding plan and she would not favor it.

McConnell returned to her original position three weeks ago after a stormy meeting with Centreville residents. She said she would support their efforts despite her serious reservations about the plan.

McConnell took a similar position last night. After delivering an emotional 10-minute defense of what she said were her efforts on behalf of Centreville residents, she criticized the legitimacy of the citizens report but said she would support it because it was favored by the vast majority of residents.

Nearly 200 residents representing many sections of the county packed the board meeting last night and delivered nearly unanimous support for the plan.

They argued that the proposal recognizes the forthcoming development of Centreville but provides for growth levels that will not significantly alter the quality of life there.

Their position was countered by developers and property owners in the area. They contended that the densities proposed by residents were too low to meet their needs and that the area was too congested to be reserved for residential development.

The board finally voted to accept the report in concept after deadlocking on several motions that would have postponed its adoption for a longer period.

Voting to accept the report in principle were Vice Chairman Martha V. Pennino (D-Centreville), James Scott (D-Providence), Thomas Davis III (R-Mason) and Nancy Falck (R-Dranesville). Voting against that motion were Herrity, McConnell and Supervisor T. Farrell Egge (R-Mount Vernon). Supervisor Joseph Alexander (D-Lee), after voting on four occasions to delay adoption of the report, broke the deadlock on the final tally by abstaining.

Audrey Moore (D-Annandale), an advocate of the citizens report, was sick yesterday and did not attend the meeting.