The head of a Fairfax County citizen group that has fought plans to close a high school in the eastern part of the county said last night that his group now supports a proposal to shut Groveton High.

Peter Brinitzer, chairman of the Neighborhood Schools Coalition of the Fort Hunt Area Inc., told a School Board hearing that his group favors Superintendent William J. Burkholder's proposal to convert Groveton into an intermediate school. That highly controversial plan would divide Groveton's 1,200 students between Fort Hunt and Mount Vernon high schools. A school board decision on the issue is expected March 14.

Brinitzer, whose group has collected more than $10,000 in donations, said the switch was prompted by a growing realization that the School Board is serious about closing a high school in eastern Fairfax because of declining enrollments.

His group's members, most of whom are from the Fort Hunt area, opted to support Burkholder, rather than a citizen task force, which had suggested the conversion of Fort Hunt because it is the smallest high school and the farthest removed from the district's growth areas.

Brinitzer said he had only one regret about the save-neighborhood-schools campaign: that it had generated much "venom" and hard feelings among the Mount Vernon, Fort Hunt and Groveton communities.

The Fort Hunt coalition's 14 officers and directors debated their position in four meetings that lasted more than 12 hours in the last two weeks, Brinitzer said. The final vote, taken Sunday, was unanimous, except for the vote of Henry Norton.

Norton said yesterday that many Fort Hunt area residents still support the coalition's original belief that the county can afford to keep all the area's schools open.