Prince George's County Executive Parris Glendening has ordered all county agencies to trim their budgets from 2 to 4 percent to save $6.9 million in fiscal 1988.

The "Resource Management" plan is an effort to reduce the county's dependence on budget reserves depleted because of an unexpected $8 million to $10 million of spending in excess of this year's budget.

The unexpected shortfall is the result of an estimated $4.4 million in pay increases likely to be contained in labor contracts being negotiated with municipal employe unions, including police and correctional officers. Also included is $2.5 million the county will waive in lease payments for the county's hospital system under terms of a proposed 35-year agreement.

"During the TRIM {Tax Reform Initiative by Marylanders, a county charter agreement limiting county tax increases} years we had to defer a number of things because our revenues were frozen," said Major Riddick, director of the Office of Management and Budget. But after the charter was modified in 1984, the county received additional revenue growth, and expanded such programs as public safety, education and aging.

Under the new plan, the county will continue to seek alternate funding sources for those programs, and will continue the implementation of a three-year, $100 million county school system desegregation program. Nevertheless, "the county government does not want to go after additional new taxing measures for the next three years," Riddick said.

To achieve a balanced budget by 1990, Glendening has directed the county to defer $120 million in planned bond sales, moderately reduce operating costs, maintain current spending levels and place a freeze on hiring, according to a report issued July 1 to county agency chiefs.

"We want to move away from dependence on reserves and live with current revenues to strengthen our financial control," Riddick said.

Budget growth for fiscal 1989 and 1990 will depend on the natural growth of the county; current development projects such as PortAmerica are raising property tax revenue 4.5 percent as property value increases, Riddick said.

And although Glendening negotiated this year in Annapolis for a first-time 5 percent tax on energy consumption and extension of a 1 1/2 percent real estate transfer tax, their revenue, an expected $33 million, are already accounted for in the $739 million budget, Riddick said.

In addition, the county holds nearly $17 million in its reserves, Riddick said, although nearly $13 million already is earmarked for spending.

"Although the proposed changes may seem painful, we must act now," Glendening said in the report.

The cuts are to apply only to general funds, and will not affect special revenue, Riddick said. For example, a large agency such as the Department of Public Works and Transportation has an $18 million budget, but would trim only 2 to 4 percent -- or between $290,000 and $580,000 -- from its general funds, which total $14.5 million.

The Department of Environmental Resources would be required to reduce its general fund budget of $5.3 million by $106,000 to $212,000.