HARRISBURG — The state's auditor general is pushing for changes in how charter schools are funded after finding that three schools received hundreds of thousands of dollars in excess tuition payments from school districts.

State law requires districts to pay roughly 75 percent of their per-pupil costs as tuition for each charter school student who lives in the district. The amount of tuition collected per student can vary widely from district to district.

The law does not require the independently operated charter schools to reconcile the amount of tuition that school districts pay to them with the actual cost at the end of the school year of educating their students, Auditor General Jack Wagner said Tuesday.

"The fact that all three charter schools were legally entitled to receive more funding than they needed to educate students underscores the critical need to fix the state's charter school law immediately," Wagner said in a statement. "We need to reassure taxpayers that their hard-earned dollars are being spent fairly and efficiently."

State Education Department spokesman Michael Race said Gov. Ed Rendell has called for revising the formula "because the current system simply does not make sense."

"It is time for the General Assembly to change the way these schools are funded so that charter schools present a choice for proven, effective education and not a blank check that deprives local taxpayers of the funds their own schools desperately need," Race said in a statement.

House Minority Leader Sam Smith, R-Jefferson, said lawmakers would likely consider revamping the formula once they receive the findings of a statewide school-cost study due later this year.

Auditors found that two Erie County charter schools, Pennsylvania Global Academy Charter School and Northwest Pennsylvania Collegiate Academy Charter School, received a combined $911,000 in excess tuition payments during the 2003-04 and 2004-05 school years. Both schools closed in 2005 to settle a lawsuit filed by the Erie School District over Pennsylvania Global Academy, which was established by the neighboring Millcreek Township School District.

The Roberto Clemente Charter School in Allentown received $475,000 in excess tuition payments from 2003-04 through 2005-06, according to a separate audit.