HARRISBURG — At first glance, it seemed that the state's school-employee pension fund would give an early Christmas present to Pennsylvania's 501 school districts and their taxpayers — a lower employer contribution rate.

But it might be a lump of coal instead.

Earlier this month, the Pennsylvania School Employees' Retirement System adopted a rate of 4.76 percent for the fiscal year that begins July 1, citing the pension fund's improved investment performance. The current rate is 7.13 percent.

In the same breath, however, the agency cautioned school districts not to count on making lower pension contributions as they begin crafting their 2008-09 budgets. The situation promises to create fiscal heartburn for school boards that have already committed to limiting next year's overall spending increase to the rate of inflation.

The state Education Department is recommending that districts stick to the current rate as lawmakers and Gov. Ed Rendell work on legislation designed to stave off a looming public pension crisis. Last year, PSERS and the State Employees' Retirement System projected that the cost to subsidize retirement benefits would triple to $3 billion a year in 2012.

The effect of legislation to blunt sticker shock would likely require districts to maintain their current contribution levels anyway, PSERS officials said.

"We believe it is prudent to ask school districts to adhere to the current contribution rate to avoid potential budget problems in the future," Rendell spokesman Chuck Ardo said.

But school districts are under pressure to draw up spending plans earlier under deadlines set by a 2006 law aimed at cutting homeowners' property taxes. Part of their calculations include factoring in the expected pension contribution rate.

Another pressure point is deciding whether to keep budget increases to within an inflationary index. Proposing a higher increase requires a district to either seek voter approval in the April primary election or permission from the state to exceed the index.

The school board in the Upper Adams School District passed a resolution limiting its budget increase to the rate of inflation just before PSERS warned districts that the reduced pension contribution rate wasn't guaranteed. That was a rude awakening for Mike Lawrence, the district's business manager.

"This puts us in a very tight place," Lawrence said.

Rep. Steven Nickol, a member of the PSERS board, has asked the Education Department to reconsider its recommendation. The Legislature could have taken a step toward alleviating the pension crisis by passing a bill that would set a minimum PSERS contribution rate of 7 percent, Nickol said, but the measure is stalled in the House.

"I will concede that if you follow through with this directive and (the bill) is enacted as it is currently drafted, the school budget process will most likely be seamless," Nickol, R-York, wrote in a letter to the department. "However, to make such assumptions presumes legislative action, and in my opinion, is far too risky."

An agreement on how to solve the larger pension problem might not surface until lawmakers and Rendell finalize the state budget about six months from now — an unsettling proposition for school districts, because their final budgets must be adopted in May.

"The nightmare of nightmares is that you get down to May and June and you still have this thing unresolved," said Jay Himes, executive director of the Pennsylvania Association of School Business Officials.

But even if the worst-case scenario occurs — school districts budget for higher contributions, but the Legislature does not act — it shouldn't result in a major property-tax increase, said Stephen MacNett, chief counsel to Senate Republicans.

"That issue itself shouldn't be the basis for a tax increase, because it's just simply continuing last year's rate," MacNett said. "If that were to occur, that would mean we've dropped the ball."