Higher than expected revenues from rising assessments could enable the Arlington County Board to cut the real estate property tax rate by as much as 13 percent, according to county budget analysts.

Four of the five board members said yesterday, however, that they expect to lower the tax rate on real property by about 11 percent to $1.29 per $100 of assessed valuation. At tht rate, homeowners who received the typical assessment increase of 12.2 percent this year, would pay the same taxes they paid last year, the analysts said.

County board members said yesterday they would prefoer to cut other taxes before cutting the real estate taxes as deeply as the budget analysts suggested.

But board members Dorothy T. Grotos and Walter L. Frankland, who have been outspoken in their support for a substantial decrease in the property tax rate, said announcement of the $7.5 million revenue windfall is "delightful."

"This sure is a fortunate situation for us," Frankland said yesterday. "'The new majority' will be able to live up to its commitments," he added.

In January, a Republican-backed majority took control of the board and proposed to cut the current $1.45 cent rate by 8 cents.

Gardner said the bulk of the $7.5 million in unexpected revenue will come from property taxes, profits from state-operated liquor stores and a higher return on the county's idle funds.

"I don't see that it would be possible to use the whole (amount) for a tax rate reduction," said board member John W. Purdy. "I want to see the teachers salaries funded, and we have to do something about the business privilege license tax, which is one of the highest in the area.

"We want to make sure we aren't reckless," Purdy said.