Prince George's County officials, citing a downturn in the regional economy, said yesterday they have curtailed the police department's ambitious hiring program and plan to sharply restrict spending elsewhere in the county government.

"Clearly, we will have to pull the belt in several major notches," said County Executive Parris N. Glendening. "Depending upon the severity of the shortfall, all options will be on the table."

Revenue from real estate transfer taxes was down 33 percent during July and August, a trend that, if it continues, could spell a $25 million drop in income for the county for fiscal 1991, John Davey, the county's chief administrative officer, said yesterday. The county, which has a $1 billion budget, also expects drops in income tax revenue if the area unemployment rate continues to increase, Davey said.

County officials also say they are keenly aware of the budgetary problems of the state and surrounding jurisdictions.

Maryland Gov. William Donald Schaefer, anticipating a possible $150 million reduction in revenue, recently ordered a statewide hiring freeze and a cutback on vehicle purchases and out-of-state travel.

Virginia officials, meanwhile, have announced that they are trimming $1.4 billion from the two-year state budget.

The most immediate manifestation of the county's budgetary concerns is the slowing of and possible cutback in hiring for the police department.

As recently as the end of August, two weeks before the Democratic primary, Glendening said in an interview that he planned to increase the force to 1,400 officers by the end of June 1991.

That goal now is in doubt in light of anticipated revenue shortfalls, county officials said yesterday.

Two police academy classes scheduled to begin in October with 70 recruits were cut to a single class of 45 students last week, county personnel director Mike Knapp said.

Training for the remaining 25 police candidates has been indefinitely postponed, with no future classes scheduled, Knapp said.

"Our Office of Management and Budget has asked that we take a more cautious approach in filling our {police} classes," said Knapp. "Basically, I've been told that there is no decision with regard to future classes."

Police Lt. Col. Robert Phillips, commander of the patrol division, said that the initial impact of the hiring slowdown should be minimal.

"It's our understanding that the county executive is still committed to reaching a 1,400-member police department," said Phillips. "At this point, all we know is that it may be delayed somewhat and in an amount yet to be determined."

Elsewhere in the county, budget cuts could curtail planned expansions for the department of corrections, the fire department and the sheriff's office, Davey said. The proposals call for 30 additional corrections officers, 55 new firefighters and 20 additional sheriff's deputies, Davey said.

There is a limited freeze on hiring, with jobs being filled on a "case by case" basis, Glendening said. Major capital projects that require bond funding may also be delayed, Glendening said.

The police department now has 1,203 officers, including 85 recruits who are scheduled to graduate in the coming months.

That represents an increase of more than 200 officers since the County Council, responding to reports of staff shortages in April 1989, authorized a major hiring program.

The patrol force -- officers at the rank of sergeant or below, who are chiefly responsible for answering calls for service -- has increased from 722 officers in April 1989 to 814 as of Aug. 31, Phillips said.

During that same time, the department has undergone an extensive reorganization and has promoted an unprecedented number of officers to the rank of lieutenant and above.

Fifty-six officers, including 19 lieutenants and 10 captains, were promoted in January; an additional 60 promotions are scheduled for Oct. 7.

Glendening said that he plans to meet with department heads on Oct. 1 to discuss spending cuts.

"I can tell you in absolute terms that other than postponing the additional officers, there have been no final decisions whatsoever," he said.