Montgomery County school superintendent Edward Andrews plans to ask the board of education today for about $339 million to run the school system in 1981-82, a 9.3 percent increase over this year's operating budget.

Andrews said the budget has pared the costs of operating the system to the minimum possible without sacrificing the quality of education.

"I regret very much that we have made virtually no improvements for students, such as expansion of all-day kindergartens or restoring the seven-period day," said Andrews. "The basic goal of this budget is to have the same capability in the schools as we have this year."

The budget includes an estimated $21.6 million to $24 million cost-of-living pay increase due teachers under the salary contract negotiated last year.

The exact amount of that increase will depend on the increase in the 1980 Consumer Price Index that will be announced by the federal government in late January.

Another $6.5 million added to this year's budget comes from increased costs for gasoline and oil, salary-related fringe benefits, utilities and placement of handicapped students in residential institutions. The budget reflects savings from a further estimated drop in student enrollment and the elimination of 77 administrative positions.

Andrews asks for about $273 million from the county -- depending on the final figure for teacher's pay raises -- up 11.9 percent from the county's $244 million share this year, and expects about $48 million from state funds and $1.4 million from the federal government.

The state's share is 6 percent greater than this year's $45 million, while the federal government's is down 36 percent from this year's contribution of $2.2 million.

Another $16 million will come from tuition and grants for various special programs and from the school food service funds

Two preliminary budget levels suggested by the County Council allocated either $329 million or $335 million for the school system, depending on whether the county funds its budget at current tax rates or with an increase in the property tax rate.

"I don't view it as my responsibility to recommend what they say, but what we need," Andrews said of the council's projections. "I would like to have recommended more."

Public hearings on the budget are scheduled for Jan. 19 and 21. The school board must present its final version to the County Council on March 1.