Bowing to the wishes of several civic groups, the Fairfax County Board of Supervisors voted yesterday to allow continued playing of instant bingo despite pleas from the prosecutor's office that the game be outlawed.

Deputy Commonwealth's Attorney Steven Merril called instant bingo - in which a player buys a preprinted card, then tears off a tab to expose a losing or winning symbol - "a game for hustlers." He said it is difficult to police because bingo cards can easily be rigged and winnings that ulti-

But representatives of half a dozen civic groups defended the game as a prime source of winnings that ultimately go to charity.

"If you cut out instant bingo, you'll be hurting these charities," warned William C. Vinet Jr. of the Springfield Knights of Columbus.

Prosecutor Merril cited the case of United Charities of Alexandria whose two principals were convicted of illegal gambling earlier this year in the operation of games for groups in Fairfax and elsewhere.

The county's administrative staff, which also asked that the game be banned, noted figures showing that 10 local organizations last year violated county law by earning more than a third of their gross receipts from instant bingo. Merril said no legal action had been taken against the groups.

Lee District Supervisor Joseph Alexander (D), himself a member of the Franconia Volunteer Fire Department, which last year earned $580,000 from bingo, scoffed at the prosecutor's objections, saying "I don't think volunteer fire departments or boys clubs are hustlers."

Alexander sponsor a motion, unanimously passed by the supervisors, rejecting the instant bingo ban but tightening restrictions on reporting receipts and auditing the books of the more than 30 groups that operate bingo games in the county.

In another matter, the supervisors unanimously expressed their support for a recommendation by Secretary of Transportation Brock Adams to remove the ban on commuter traffic on the Dulles International Airport access road.

At a public hearing last night, an organization called SCORE (for Support and Conserve Our Residential Environment) presented petitions bearing nearly 1,600 signatures opposing a county plan proposed for land known as the Chiles tract at the intersection of Rte. 50 and the Capital Beltway.

The plan calls for light industrial and high-density residential development for 150 acres at the intersection's northeast quadrant and hotels, offices and more high density residential development at the 192-acre southeast quadrant.

A vote on the plan was deferred until July 23.