A Virginia legislative committee today rejected Fairfax County's proposal to create a special government for Reston and endorsed a plan allowing residents of the Northern Virginia community to vote on whether to become a town.

The action was a jolt for Fairfax County officials who fear incorporation of Reston would prompt many of the county's other neighborhoods to seek transformation into semi-independent towns. Legislators today scoffed at Fairfax's plans to turn Reston into a special government as creating "a high-class sanitary district."

"This is very bad news," said Fairfax Supervisor James M. Scott (D-Providence), who had joined his colleagues in a unanimous vote last month to support the creation of a more limited form of government for Reston. m

"I don't think the county government should be broken up into towns, further Balkanizing the county. It will only make the operation of government more expensive."

Efforts to incorporate Reston as a town in the past have been consistently opposed by Fairfax officials, who have argued that such a move could cause economic hardships to the county. Some of Fairfax's state revenue sources would be siphoned off for the new town, they say.

The Local Government Committee declined to consider a county-approved compromise measure that would have labeled Reston a "chartered community" and given it the power to elect its own mayor and council, levy property taxes, run a transit system and manage public parks.

It is unlikely that the county's bill, sponsored by Sen. Charles L. Waddell (D-Loudoun), will ever get out of committee. A subcommittee appointed to study the matter voted 4 to 1 this week to postpone the chartered community plan at least until next year, with Waddell casting the only dissenting vote.

"We just didn't like the idea of giving the Fairfax County Board of Supervisors the power to create or destroy a governmental body," said committee member Sen. Wiley Mitchell (R-Alexandria). "Even a sanitary district has certain defined power and is not subject to being abolished at the whim of the supervisors."

The committee voted 10 to 5 today to report out another Waddell proposal that called for a referendum of Reston voters. Fairfax officials had argued that such a basic change in the county's government should not be allowed unless all county residents were polled.

Terry O'Brien, the county's lobbyist, told committee members that county residents approved an urban county executive form of government in 1967 with the understanding that it prohibited the formation of any new towns within the county's boundaries. "This proposal runs contrary to what the people of Fairfax agreed to," he said.

Sen. Joseph V. Gartlan (D-Fairfax), one of the five committee members opposing the referendum, said the panel's decision was "nothing more nor less than a breach of faith with the people of Fairfax County."

The measure faces an uncertain future on the Senate floor this week, Waddell said. He said he might consider altering the Reston referendum proposal to include all Fairfax County voters if it would aid the bill's chances.