Prince George's County Executive Lawrence J. Hogan is preparing a budget that will call for $16 million greater spending than this year but would lower property tax bills slightly for most home owners, according to sources familiar with budget preparations.

The tax bill reduction is the result of the tax-limiting TRIM county charter amendment approved by voters in 1978 that freezes the amount of property tax the county can collect.

Despite the taxing restrictions, Hogan is able to increase the budget and avoid severe cuts in programs and services that many officials predicted because of greater state aid, a larger-than-expected surplus from the current budget and some economy measures put into effect in the last year.

The $474 million budget is expected to call for cutting the property tax rate by at least six cents from the current rate of $3.04 per $100 of assessed valuation. That would cut the tax bill on the average $50,000 county home by $15. The reductions would go to the two-thirds of county home owners whose homes were not reassessed. The one-third who were reassessed would probably pay no more than they did last year, the sources estimated, because the increase in assessments would be balanced by the tax rate cut.

Although Hogan promised voters when campaigning for county executive two years ago that he would cut millions of dollars from the budget if elected, both his budgets as executive have shown increases.

During that campaign Hogan vigorously criticized his opponent, incumbent Winfield M. Kelly Jr., who maintained that the budget could not be cut but promised to hold future increases to four percent.

Sources said yesterday that because the 3.3 percent spending increase proposed by Hogan for 1981 is much less than the current 18 percent inflation rate for this area, Hogan's office is preparing to defend it as the equivalent of actually cutting the budget.

Several members of the all-Democratic County Council, which will review and perhaps change Hogan's budget, called the $16 million increase reasonable, but they chided the Republican executive for failing to accomplish his campaign promise of budget cutting.

"Mr. Hogan is just coming around to what we all knew," said council member Deborah Marshall. "He's come to face reality. There was no way he was going to be able to do what he said."

The budget will be released publicly March 31 when it is forwarded to the council.

Hogan plans to propose no major reductions in county programs in the fiscal 1981 budget, the sources said. Cutbacks will be made in staffing, where Hogan is planning across-the-board cuts in now-vacant positions. None of those job reductions would affect the police, fire, corrections or sheriff's departments, sources said.

Hogan also apparently has agreed to give the Board of Education most of the money it has requested through a combination of increased state aid and county funds.

He will recommend that the board reduce some administrative expenses and staff and will propose elimination of some environmental education programs and junior ROTC, both of which he tried unsuccessfully to eliminate last year.

Sources said Hogan has not yet decided whether to recommend that the board consider closing as many as 20 schools, which would save as much as $2 million in operational costs.

Unlike last year, Hogan will not recommend an increase in fees for any county services or the imposition of new fees for services that are now free, the sources said.

"We just don't see any major cuts coming up," said one official familiar with the budget proposals.

Just this fall, Hogan was predicting dire problems for the county because of the financial squeeze imposed by TRIM. In a meeting with members of the state legislature last September he said that the county faced a potential $28 million gap in costs that it would not be able to fund.

That gap apparently was eliminated because of large increases -- about $23 million -- in state aid for education, police, transportation and Metro. The state aid package still must be approved by the legislature.

Hogan's budget also was aided by increases in the county's income from investments and a fund surplus that is at least twice as large as the $8 million Hogan predicted last fall, sources said.