The Virginia House of Delegates today overwhelmingly approved a $94.6 million corporate tax bill that Gov. Charles S. Robb says the state needs to offset the impact of federal tax cuts and raise the salaries of the state's classroom teachers.

While today's action does not guarantee that teachers will receive the 10 percent annual pay raise Robb has promised them, a spokesman for the governor said he is optimistic that the legislature will spend part of the new revenues on them. Members of the Senate's finance committee are meeting this weekend to begin dividing up the funds that the corporate tax measure is expected to raise.

The bill previously passed the Senate, which is expected to concur next week with several House amendments that legislators described as "technical."

Robb maintained last month that the $13.1 billion two-year budget proposed by former Gov. John N. Dalton was sufficient to cover the Reagan budget cuts and raise teacher salaries to the national median by 1984. He reversed himself recently after the House budget committee found his revenue proposals were at least $20 million short.

Approval of the corporate tax measure came the same day that the Senate approved, on a vote of 25 to 11, a wholesale gasoline tax measure that includes no additional funding for the Washington area's Metro transit system. Northern Virginia legislators, who fought unsuccessfully to include $13.3 million worth of Metro funds in the gasoline tax measure, said they are now hoping to carve at least $18 million for Metro out of the corporate tax bill.

"I hope we're going to come out all right," said Sen. Adelard L. Brault (D-Fairfax), the leader of the Metro funding fight in the Senate. "I pray every day."

The corporate tax measure passed today 77 to 15 despite the protests of some Republican delegates. Under the bill, Virginia corporations will be required to defer for two years $75.6 million in corporate tax breaks that Congress recently enacted as part of the Reagan administration tax plan. Another $34.2 million will be raised through the delay of a scheduled phase-out of a gross receipts tax on public utility companies.

On the House floor today, proponents maintained that the state needs additional revenues to offset a total of $190 million that Virginia will lose as a result of Reagan's tax cut package and federal fund cuts. Because the state conforms to federal tax laws, Virginia would automatically lose $112.1 million in accelerated depreciation for business assets.

"The impact school aid funds and things we get from the federal government are very much in limbo, if not cut off completely," said House Majority Leader Thomas Moss of Norfolk. "We need these funds, especially for our schools."

Another proponent, Del. Lewis Parker (D-Mecklenburg), argued that the measure will save private industry some $15.2 million through two key sections that repeal many of the state's business licensing taxes and many taxes on business assets.

Opponents labeled the measure a "shell game," and said it would discourage industry from doing business in Virginia. "At a time when we're trying to create new jobs and new industry, it is wrong to penalize those very sources of new jobs," said Del. George Jones (R-Chesterfield.)

Backers of the bill said its revenues will be used to fund the teacher salary increases, prison construction costs, local jail operations, and expand the state's $5 million budget cushion.

Today's action leaves the Metro funding situation uncertain, with the Northern Virginia delegation entertaining several seemingly contradictory plans for finding a new funding source for Metro.

Members of the Senate are hoping to get Metro operating funds tucked into the budget through the Senate Finance Committee this weekend. Many legislators say the committee's acting chairman, Sen. Hunter B. Andrews (D-Hampton), has been threatening privately to cut out even the $13.7 million in Metro funds that has House approval.