School superintendents in Montgomery and Prince George's counties are proposing modest budget increases for next year, despite declining enrollments that will leave each system with fewer students.

Patrons of both school districts will have a chance to voice their opinions at hearings scheduled this month.

In Montgomery County, public hearings on the proposed budget have been set for 7:30 p.m. Jan. 17 and Jan. 18 in the Educational Services Center auditorium at 850 Hungerford Dr. in Rockville.

In Prince George's County, three public hearings will be held: Southern area - 7:30 p.m. Monday, Southern area office auditorium, 7711 Livingston Rd., Oxon Hill; Central Area - 7:30 p.m. Wednesday, multipurpose room of Largo Senior High School, and Northern area - 7:30 p.m. Jan. 16, auditorium of Eleanor Roosevelt Senior High School.

Copies of the proposed Prince George's budget have been sent to all county public schools and are available for study at school libraries.

In messages to their boards of education, Montgomery Superintendent Charles M. Bernardo and Prince George's Superintendent Edward J. Feeney cited inflation, teacher and staff salary increases and increased spending for special education as major reasons for the proposed budget hikes.

Special education spending is mandated by federal legislation that requires all handicapped children receive appropriate schooling.

In Montgomery County, Bernardo is seeking $270,827,940 for the fiscal year beginning July 1 - an increase of $15.5 million, or 6.5 per cent, over current spending.

In Prince George's County, Feeney is urging adoption of a $253,205,436 budget - an increase of $7.9 million, or 3.2 per cent. However, Feeney's proposal does not include pay raises yet to be negotiated with the Prince George's County Educators Association, so the final figure is likely to be somewhat higher.

In fiscal 1979 both counties will face the continuing issue of school closings. Bernardo has urged that six more schools be closed in Montgomery County, effective at the end of the current academic year.

In Prince George's, Feeney has made no specific recommendations about school closings, but he has noted that by next September declining enrollments will mean about 4,000 more empty classroom seats in elementary schools, which already have 15,000 vacant desks.

Prince George's County closed 10 schools at the end of the last academic year, while Montgomery has closed or consolidated 22 schools over the past three years.