The House Finance Committee dealt Virginia Gov. John N. Dalton a stunning and dramatic defeat today, rejecting on a tie vote a compromise two-cent per-gallon version of his proposed gasoline tax increase.

The action means the proposal is virtually dead for the session, throwing into doubt legislative attempts to provide money for Metro construction costs. A separate bill that would tax only Northern Virginia gasoline users is before the Senate, where its prospects are unclear.

The outcome shocked Dalton's aides and supporters, who believed up to the moment of the decision that they had at least 12 votes on the 20-member committee. They blamed last-minute switches by a Northern Virginia Democrat and a suburban Richmond Republican for the defeat.

But opponents said the refusal of Dalton and Del. Vincent F. Callahan Jr. (R-Fairfax), the bill's sponsor, to bind themselves to the two-cent compromise doomed the proposal, which was defeated on a 10-to-10 vote.

"If we'd have had their commitment, we'd have had a gas tax," said Finance Chairman Archibald A. Campbell (D-Wythe), who last week had told Callahan he would support some sort of gasoline tax compromise.

Dalton, who made the gasoline tax increase his key legislative issue this year, had proposed using the tax revenues for both Metro and highway construction.

Campbell and other committee members said they were well aware that Dalton's strategy was to agree to a two-cent bill from the committee, then attempt to get the bill amended to three or even four cents when it reached the less hostile Senate Finance Committee. To thwart that plan, Campbell had sought Dalton's commitment this morning to adhere to the two-cent limit. The governor refused.

"We just didn't feel we should be in the position of binding the Senate," said Dalton spokesman Paul G. Edwards, adding he was "very surprised" at the outcome. "We felt we made the case for four cents," he said.

Dalton's backers said they had never counted on Campbell's support for the bill and were not surprised at his opposition today. But they said they had counted on Dels. Warren G. Stambaugh (D-Arlington) and George W. Jones (R-Chesterfield) to support the bill.

Jones said he changed his mind after Dalton and Callahan refused to agree to the compromise proposal. "I came here today with the intention of voting for two cents," said Jones.

Callahan said the committee's refusal to pass some sort of increase could have a devastating effect on highway construction and maintenance in the state. Dalton and the state highway department have pointed to decreasing revenues from the gasoline tax because of reductions in gasoline consumption. At the same time, costs have soared more than 15 percent a year due to inflation.

"I'm very disappointed in the action of the House Finance Committee," said an obviously stunned Dalton afterward. "I made a proposal for new motor fuel tax revenues that I felt were essential to an adequate highway and transportation program for Virginia."

But Jones, who like Dalton is a conservative Republican, said, "This commonwealth has been in crises before . . . we won't go down the tubes in 12 months [when the assembly meets again]."

Stambaugh denied he had ever pledged his support to the Dalton proposal.

"My position had always been I'll vote for it only if it has Metro money," said Stambaugh. Before it voted down the proposal, the committee defeated a Stambaugh amendment that would have committed a share of the revenues raised to Metro construction.

"Don't talk to me, talk to Mr. Jones or Mr. [John S.] Buckley [a Fairfax Republican who also voted against the tax]," said Stambaugh, a Democrat. "They're members of the governor's party, not me."

There was speculation after today's vote that Dalton's Senate supporters may revive his proposal by tackling a statewide tax amendment onto a Stambaugh bill raising Northern Virginia's gasoline taxes four percent to pay for Metro. That bill has already passed the House, but faces an uncertain future.

"The defeat of this bill here puts the Metro bill in trouble over there [in the Senate]," said Callahan, who said many lawmakers will be reluctant to improve a regional increase alone.

Today's vote climaxed more than six weeks of legislative debate and intrigue over the tax, first proposed by Dalton in his opening address Jan. 9. Campbell, who was adamantly opposed to the proposal, kept the bill bottled up in his committee for more than a month of study and hearings.

Campbell and other opponents said they simply did not believe revenue projections from the state highway department, which would receive and dispense money raised from the tax increase.

They criticized Dalton for not proposing a proportional increase on taxes paid by heavy trucks, which they argued caused the most highway damage. Mail from constituents also ran heavily against the increase.

Dalton rallied support in recent weeks from powerful state interests such as farmers, retail merchants and other business groups. His supporters thought they had achieved a final breakthrough last week when Campbell announced his willingness to compromise on the bill.

But Campbell was only willing to support a 1.5 cent-per-gallon increase and he wanted Callahan's commitment not to seek more from the Senate.

Callahan said that arrangement smacked of politics of West Virginia or Maryland" and he refused to go along. "The governor would rather see the bill killed than do that," he said.

Campbell, who said an agreement would have been a "compromise, not a deal," warned before the vote, "If this committee reports out anything . . . it's out and the governor and the chief patron will take it to four cents or 15 cents or anything they want."

And another opponent, Del. Richard Cranwell (D-Roanoke County), said the two-cent proposal was "just a Band-Aid." He warned that the highway department would be back for more money in a few years and "we'll be agonizing over it again."