The Fairfax County school superintendent yesterday proposed a $329-million budget for the 1978-79 school year that calls for higher salaries for all employees, increases programs for the handicapped, smaller classes and the opening of three new schools.

School Supt. S. John Davis described his proposed operating budget of $264 million - the single largest portion of the school budget - as a "reasonable budget, not a bare bones or hold-the-line document like presented in the past."

The overall budget is 14 per cent higher than the current budget of $288 million. More than 30 per cent of the schools' $264 million operating budget, which is 9 per cent larger than last year, would be financed with state and federal funds. County tax-payers would have to pay 63 per cent, or $167 million - an increase of 13 per cent over last year. The remaining would be financed by a variety of sources.

Fairfax's deputy county executive, James P. McDonald, said he sees no need for a tax boost to pay the county's increased share of school support, an increase that "had been anticipated."

Davis said he anticipates no problem in winning approval from the county board school for the budget, abut noted that if cuts are necessary, the proposed 7 per cent cost-of-living salary increase and fringe benefits for school empolyees "would be the first looked at for trimming." The county Board of Supervisors has already asked that cost-of-living pay boosts be held to 5.5 per cent.

Victor Cornacchione, president of the Fairfax Education Association, which represents most county teachers, said he was "disappointed" that the proposed pay increases would be the first item considered for cutting.

He said the association "would fight to keep the 7 per cent that allows school personnel to compete with the federal employee at the market."

Davis blamed most of the cost increases in his proposed budget on the state and federal government. He said both governments are requiring increasing educational programs and services without providing enough money for them.

Salaries and benefits for existing employees represent the largest portion of the budget (86 per cent). Davis said that more money is needed to hire 153 new teachers and other school personnel to comply with state and federal laws and to staff the three new elementary schools.

Fairfax next year muset hire 138 teachers to teach through sixth grades, the result of a Virginia State Board of Education edict requiring that these classes be reduced in size from 30 to 28 pupils.

Davis said he plans to notify the State Department of Education that unless more state funding is provided to meet this requirements, the Fairfax school system will ignore the requirements or only partially comply with it. Davis said Fairfax also need 38 more teachers to comply with the state board's standards of quality, under which no class next year in grades one through three can exceed 31 pupils without having a teacher and an aide.

Federal special education programs and programs for the handicapped require the school system to hire 35 teachers and 54 psychologists, visiting teachers, placement personnel and clerks, according to school personnel official Philip Sharpe.

Forty teachers, guidance counselors, principals and custodians will be hired to staff the new South Lakes High School in Reston, Reston No. 6 Elementary School and a new center for multiply handicapped children at Kilmer Intermediate School.

These hirings, which will cost about $5 million, would offset a saving of $1 million that resulted from eliminating 94 teaching positions due to declining pupil enrollment. Thus, while school enrollment is projected to decline by 1,246 pupils next year, the number of employees will continue to increase in order to staff smaller classes and smaller, more specialized school programs.

The nonoperating portion of the overall school budget (24 per cent) includes costs for interest on previous school board issues, the self-supporting school lunch program, the employees retirement fund and school construction.

Fairfax school finance director Myron E. Cale called the 14 per cent increases in the overall budget from last year a "distortion" because the school construction fund contains $15 million "that the schools won't pay out this next school year."

"The state requires us to have enough cash in hand to pay for multi-year projects," Cale said. "If you take out that money that is budgeted in advance, you have only a 9 per cent increase in the entire budget - same as the operating budget."