The Arlington school board adopted a budget proposal last night that calls for $640,000 more than the county board, which provides the money, has indicated it is willing to pay.

The $53 million budget approved on a 3-to-1 vote maintains the 10.5 percent pay raise for school employes offered by School Superintendent Larry Cuban when he made his budget proposal last month.

The county board had asked the school board to limit spending increases this year to 5 percent. The original budget would have exceeded that guideline by $1.1 million, a figure the school board managed to cut almost in half.

But Walter Frankland, County Board chairman and a frequent critic of the school system, said yesterday he was still unsatisfied with the school budget.

"They're moving in the right direction," said Frankland. "It sounds like the only thing that separates the guideline and what they are okaying is the amount of increase in salaries, which is apparently 1 percent higher than what the county board requested for county employes. That seems to be the area we'll be working on."

County Manager W. Vernon Ford presented the county government budget earlier this month calling for a 9.5 percent salary increase for county employes.

School employes have already told the school board they consider its planned 10.5 pay increase inadequate. Majorie Sale McCreery, president of the Arlington Education Association, which represents 90 percent of the county's 1,000 teachers, has said the school proposal would not be enough to halt the "work-to-the-rule" job action that Arlington teachers began a year and a half ago in a salary dispute.

The one school board member who voted against the budget was O. U. Johansen, who was appointed to the board last year by Frankland. Johansen said it would be "unrealistic to come in with a budget higher than the guidelines." When pressed by school board member Mary Margaret Whipple as to where he would trim the budget, Johansen said he would rather not discuss it immediately.

"We may as well wait for the word we're going to get," from the County Board, Johansen said.

Other school board members have argued that the County Board will have little excuse to avoid funding the full budget. With real estate assessments rising by an unprecedented 23 percent in Arlington this year, even with an expected cut in the tax rate there is expected to be a considerable increase in county funds.