A Virginia Senate committee today approved a bill, angrily opposed by religious fundamentalist ministers, that would deny state tax exemptions to schools that discriminate on the basis of race.

The measure would affect at least 11 all-white private academies in the state whose tax status already has been clouded by the Reagan administration's controversial decision that it would no longer revoke tax breaks to racially discriminatory schools.

The bill struck a firestorm of criticism from fundamentalist ministers today who denounced it as the state legislature's most serious attack on the First Amendment in years. After the measure cleared the Senate Finance Committee by a 9-to-3 vote, the clergymen vowed to launch a major statewide lobbying campaign to ensure its defeat before the General Assembly adjourns on Saturday.

"This legislation presents the greatest threat to religious freedom in the history of our country," Ron Johnson, pastor of the Loudoun Baptist Temple in Leesburg, told the Finance Committee at a public hearing.

"It would be the usurping of a power that was given to us by God and never intended to be taken away from us," echoed Bud R. Calvert, pastor of the Fairfax Baptist Temple in Annandale. "It would be in opposition not only to the Bible but to our First Amendment rights."

The ministers' lobbying efforts already have begun. Last week, at the Old Dominion Church School Association's statewide basketball tournament in Henrico County, they set up a small office next to the gymnasium to hand out literature urging parents and students to contact their state legislators. The group-- together with the Virginia Assembly of Independent Baptists--has sent out similar alerts protesting the measure to thousands of members throughout the state.

The battle over the bill, sponsored by Sen. L. Douglas Wilder (D-Richmond), the Senate's only black member, is a sideshow to a national dispute that began Jan. 8 when the Reagan administration, reversing longstanding U.S. policy, said it would stop denying tax exemptions to schools that discriminate, claiming the denials lacked clear statutory authority.

That policy, denounced as racist by civil rights groups, has since been thrown into confusion by a series of conflicting announcements by administration officials.

Fundamentalists, meanwhile, apparently have succeeded in killing a bill introduced in Congress aimed at granting the specific authority the administration claims it needs to continue denying the tax breaks. The issue is expected to remain unresolved until the Supreme Court rules on it.

While U.S. policy remains unclear, Wilder said he wanted to ensure that Virginia, whose tax laws automatically conform to the federal government's, would not inadvertently restore tax-exempt status to discriminatory academies in the state.

"This bill would be an indication that Virginia doesn't want these schools to have tax exemptions ," Wilder said today. "If they want to practice discrimination, let them pay for it."

The ministers who opposed Wilder's bill today said that, unlike all-white academies, the scores of religious schools they head routinely admit black students. But they claimed the measure would be the "first step" toward the imposition of secular beliefs on religious institutions.

"I have many church members and students who are black," said James Sumpter, pastor of the Landmark Baptist Church in Henrico and vice president of the Old Dominion Church School Association, which represents 40 fundamentalist schools with about 4,500 students in the state.

"But we do teach that the Bible says it's wrong to have interracial marriage," he added. "That's a biblical belief that we have and that could be used against us."

"There's no issue of discrimination here," added Calvert. "I just don't like the government getting in and telling us how to run my church. It's a horrible infringement on our rights. Maybe they'd say we were discriminating unless we ordain homosexuals or maybe they'd say you have to have Communists in our schools. Can you imagine having the government trying to police that?"