Officials in Richmond called untenable the idea of increasing Virginia's sales tax to offset cuts in school spending, a suggestion made this week by the chairman of a group of 21 Northern Virginia school superintendents.

Arlington Superintendent Arthur W. Gosling urged Tuesday that the General Assembly increase the sales tax by 0.5 percent when it convenes next month.

Expected cuts in state aid to school systems next year "are going to hurt the children," he said during an address to his colleagues. "We don't have fat in our budgets."

Education officials say as much as $150 million in education money could be cut next year to help the state balance its budget. Gov. L. Douglas Wilder has predicted a $1.4 billion shortfall in revenue needed to cover the current two-year state budget.

To temper the cuts, Gosling said, the state could earmark for education money raised by increasing the 4.5 percent sales tax. "New revenue sources have got to be found," he said. "We would like {legislators} to think about a bigger pie."

Legislators and state education officials say they empathize with the financial trials school systems face, but those contacted offered almost no hope of a new tax.

"In 1991? Poor to nil," said state Sen. Charles L. Waddell (D-Loudoun). "It's election year for 140 legislators."

Sen. Edward Holland (D-Arlington) said the timing for new taxes is wrong. Not only is Wilder staunchly opposed to new taxes, but it would be nearly impossible to implement a tax increase in time to have an effect next year, he said. "All the signs are down," he said.

Joseph Spagnolo Jr., Virginia's superintendent of instruction, said he supports the idea of new revenue to offset education cuts. But a sales tax increase "just does not seem to me to be a politically popular thing," he said.

Gosling made his remarks at the Westpark Hotel in Leesburg at a meeting of the Region IV Superintendents Study Group, school officials from 15 counties and six cities in the northern quarter of the state who meet regularly to discuss education issues.

The meeting came a month after a proposal that the state transfer as much as $85 million in education aid from some affluent Northern Virginia systems to poorer systems downstate, beginning in 1992.

Under that plan, developed by a panel appointed by Wilder, Fairfax County would lose $64.9 million in the two-year budget that takes effect July 1, 1992, Arlington would lose $9.3 million, Alexandria would lose $5.5 million and Loudoun County would lose $4.6 million.

"We should not diminish one to help the others," Gosling said.