Alexandria School Superintendent Paul W. Masem presented a $75.5 million budget proposal last night that would deny cost-of-living raises to teachers, eliminate 42 support staff positions and represent the system's first ever decrease in per-pupil spending.

Masem described his 1991-1992 proposal, which is $240,000 less than current spending, as "less than adequate" to address the needs of today's diverse student population. His request was shaped largely by an expected 24 percent drop in state financing from $15.4 million to $11.8 million.

He said a "terrible price" may be paid in the future for failing to finance adequately students' education needs today.

Masem's proposal contains across-the-board trims, with the largest cuts in services and capital expenses. The proposal also expresses frustration that the State Department of Education and Gov. L. Douglas Wilder have failed so far to send clear signals as to state funding cuts, making meaningful planning difficult.

Despite the estimated shortfall from the state, the proposal seeks a city appropriation of $63.2 million. The 5.7 percent increase over the current appropriation falls well below the 6.1 percent spending ceiling targeted by the City Council.

In the last two years, Masem strained relations between the School Board and the City Council by offering budget proposals well in excess of spending limits sought by the council. The School Board was forced both times to reduce its request by several hundred thousand dollars.

Council member Kerry J. Donley (D) said he was pleasantly surprised by Masem's proposal this year. "I figured it would be a round of the same deal," he said in an interview yesterday afternoon.

Donley praised the proposal for recognizing "that Alexandria is faced with the same economic woes" as the rest of the region, and for protecting educational programs by making the largest cuts in support areas.

R. Alan Caudill, executive director of the Education Association of Alexandria, said many of the association's 700 members accept the superintendent's position that "there just isn't any money to provide a lot of programs or salary increases."

Teachers will receive an estimated 2.8 percent pay increase through seniority, or step, increases provided by their contract.

Masem and Caudill said separately that they would expect school employees to receive any general salary adjustment that the City Council might give city employees. City Manager Vola Lawson will present a citywide budget proposal early next year.

Though Masem hopes to cut 42 support staff positions through attrition, he has recommended 21 new teaching slots, including 6.5 in elementary schools, to compensate for an expected increase of 100 grade-school students.

Masem also included seven new teaching positions for English as a second language to serve a rising population of immigrant children. More than one-quarter of Alexandria's 9,592 students are enrolled in special education or the English programs.