Montgomery County Executive Charles Gilchrist yesterday proposed trimming 95 of 5,400 teaching positions from a budget submitted a month ago by the county school board.

In cutting $3.6 million from the board's request for $337 million for the coming fiscal year, Gilchrist's plan would also eliminate 53 jobs for teaching aides, 19 for administrators, clerks and secretaries and 19 for security officers that the board is seeking. At a press conference yesterday, Gilchrist sounded his now familiar theme that the Maryland county can hold back spending increases and reduce government rolls without significantly harming the quality of services.

Further savings would be accomplished by lowering outlays for textbooks, drawing on a trust fund instead of the budget for some life insurance payments and paring certain special education programs.

But county School Superintendent Edward Andrews said he was "very much concerned" about an adverse impact on education if teaching staff is reduced by 95 positions. Such a cut could bring about larger classes and reduce the variety of courses now offered, he said.

The competing budgets devised by Gilchrist and Andrews will be debated by the County Council, which holds ultimate authority in appropriating county funds. Budget hearings began on Monday night and will continue until next week.

Both budgets call for increased spending on education but reductions in the sytem's current staff of about 11,600 people. After years of growing student enrollment, county schools are now facing a decline. The current student population of 99,000 is expected to slip to about 95,000 in the coming school year.