When Prince George's County voters lifted their self-imposed property tax restrictions last year, it had a ripple effect on county finances, one that will allow for significant improvements in parks and recreational facilities this year, county administrators report.

The Tax Reform Initiative by Marylanders (TRIM) charter amendment approved by county voters in 1978 limited tax collections to $144 million annually for each of the next six years.

County budget analysts have predicted that by lifting the cap -- and at the same time freezing the county's tax rate of $2.40 per $100 assessed value in unincorporated areas -- $8 million in new money will flow into county coffers during the fiscal year that begins in July. About three-fourths of the county's population lives in those areas, according to county officials.

A side benefit, outlined by County Executive Parris Glendening in an announcement last week, is that for the first time in 10 years the Maryland-National Capital Park and Planning Commission -- the bicounty agency that oversees parks in suburban Maryland and includes the planning boards of Montgomery and Prince George's counties -- will be able to sell $8.2 million in bonds.

Proceeds from that bond sale will pay for improvements to recreation centers and parks scattered throughout Prince George's. Montgomery County's $32.6 million budget is also awaiting County Council action there.

After each council has approved its part of the commission's operating budget, the full budget will be approved by both councils meeting jointly.

"While park and planning technically was outside of [the restrictions imposed by] the TRIM amendment, as a practical matter previous county executives and councils . . .felt that the park and planning budget ought to be held to the same growth as the budget under TRIM," Glendening said.

Overall, the county's six-year plan for its capital improvement program will total $564.9 million, compared with the $261.7 million that had previously been allotted for capital improvements for 1985-1991.

The increase, which includes federal, state and local funds, means that "Prince George's County is a community ready to invest in itself," Glendening said.

Last year, the county imposed a 3 percent increase in the park and planning property tax rate, a separate tax levied to raise money for parks. At the same time, the county's overall tax rate decreased by 11 cents per $100. Most of the revenue generated from the increase was designated to finance park maintenance programs. Between 1979 and 1985, the parks tax rate increased only 3 cents, a 7.6 percent increase that placed the park and planning commission in a "position of retrenchment," Glendening said in his budget message last year.

In Montgomery County, a separate parks tax rate is also imposed. This year's proposed rate is 25 cents per $100 assessed valuation.

If the Prince George's park and planning budget had significantly increased while the county's operating budget was functioning under straitened circumstances, Glendening said, the increase might have been perceived by taxpayers as "an end run around TRIM."

The bond sale announced last week will finance:

* The construction of three new community centers, in Upper Marlboro, Chillum and Harmony Hall.

* Renovations and additions to community centers in Seat Pleasant, Mount Rainier, Beltsville and other locations.

* Improvements to ballfields and parks in Colmar Manor, Silver Hill, Riverdale and other locations.

Also included in the parks package was money that Glendening had promised state legislators he would allocate from local bond money. He did that in exchange for their support for a state bond bill that will provide $1.8 million in start-up funds for the construction of a new satellite government center in Hyattsville.

The proposed park and planning property tax rate, which is separate from the county's property tax rate, is set at 46 cents per $100 assessed valuation and will not rise.

The park and planning commission's total proposed budget is $37.8 million, up 6 percent over this year.

The county will also sell $27.5 million worth of bonds in July to finance a shopping list of capital projects that have been approved by voters in previous elections.

These include bond issues for:

* $9 million in public safety improvements ranging from the construction of a new Hyattsville police station to the move of the Seat Pleasant Station to the old Kent Junior High School.

* $1.5 million for renovations and additions to school facilities. Renovation of the old Camp Springs Elementary School at a cost of $1.6 million to turn it into a new Camp Springs Government Center.

* Repair of roads and bridges and improvement of 23 miles of curbs, gutters and sidewalks throughout the county at a cost of $10 million.