The Virginia House of Delegates overwhelmingly approved today a bill that would reform the state's bingo laws, but the measure is likely to be strengthened even further when the Senate considers the legislation.

House members voted 93 to 6 in favor of mandating stricter regulation of bingo, which has proved lucrative, to private operators as well as the charities and nonprofit groups the existing bingo law was supposed to benefit. Some bingo operations in Northern Virginia have led to several recent gambling prosecutions.

But the House stopped short of outlawing instant bingo unless localities specifically ban that game. The player of instant bingo purchases a card and learns whether he has won by uncovering "windows" on it.

Sen. Wiley F. Mitchell Jr. (R-Alexandria) promised today to seek a statewide ban on instant bingo, and he said he and other senators would also try to limit to three the number of days per week bingo events may be held in any one facility.

Saying the House had reversed a policy decision supported by a special bingo reform study committee, Mitchell complained that allwoing unlimited use of facilities for bingo "constitutes at least a tacit stamp of approval by the legislature to continue and expand professionally operated bingo parlors."

Del. Ralph L. Axselle Jr. (D-Henrico), who chaired the House subcommittee that helped draft the bingo bill, said he originally supported limiting the use of a bingo facility to three times a week but changed his mind after hearing testimony from bingo operators.

In a separate development of major interest to Northern Virginians, a Senate committee approved a local tax measure designed to help meet the increasing costs of the Washington area's Metro transit system.

The bill, proposed by Sen. Omer Hirst (D-Fairfax), would allow five Northern Virgiania localities to impose an additional 1 percent retail sales tax. An almost identical measure passed the Senate last year 35 to 5 but failed by one vote in the House.

Gov. John Dalton, who looks with disfavor on any local tax legislation, has warned he will probably veto the measure if it passes.

In other action today, a House committee voted 19 to 0 for a bill that would prohibit the Chesapeake and Potomac Telephone Co. from charging for local services based on the number and length of phone calls.

The bill, strongly opposed by telephone company lobbyists, is sponsored by Del. Richard L. Saslaw (D-Fairfax) and 73 other cosponsors, a number more than enough to guarantee its passage in the House. The bill also is considered to have wide support in the Senate.

In other assembly action, the Senate narrowly approved a bill requiring public schools to close for general elections, which occur annually in Virginia. The vote was 22 to 18. The measure now goes to the House, where its future is uncertain.

The bill was opposed by the Fairfax County school administration and the State Department of Education. Even so, all Northern Virginia senators except Mitchell, the Alexandria Republican, voted for it.

All Northern Virginaia schools currently hold classes on election day.