RALEIGH - At least 90 percent of Wake County high school students could graduate from high school -- provided there's a massive boost in money, school leaders say.

The school board agreed Tuesday to set the goal of having 90 percent of students graduating from high school by 2013 and 95 percent by 2015. But the board tied that goal with an increase in county money, possibly as much as an 80 percent increase over the next six years.

"It's important for the public to know it's possible -- with funding," said Rosa Gill, chairwoman of the school board.

But the board's insistence on more money could escalate tensions with Wake county commissioners. A majority of commissioners seem inclined to back a far more modest $18.5 million increase in county money for schools for the coming fiscal year instead of the $54.7 million boost requested by the school board.

Improving the graduation rate is a laudable goal, said Joe Bryan, chairman of the board of commissioners. But he said they also have to keep in mind what the community can afford.

"I'm glad they're having this significant policy discussion, but there's more that we have to do," Bryan said.

The graduation goal was set as part of a proposal from two major civic organizations, the Greater Raleigh Chamber of Commerce and the Wake Education Partnership, to reduce the bickering between the school board and commissioners.

Under the proposal, the school board would turn over school construction to the county in return for developing a multiyear formula that would lead to more money for education.

A key part of the plan calls for developing a way to measure how academic achievement will be improved by increasing school dollars.

Wake already has a fairly high graduation rate, but Superintendent Del Burns said the district can do better. In Wake, 79.3 percent of students graduate from high school in four years, compared with the state average of 69.5 percent.

But board members repeatedly stressed that the new goals would be attainable only if they got enough money from commissioners. They blamed lack of money from commissioners for Wake's falling short of a goal of having 95 percent of third- through 12th-graders passing state exams by 2008.

Though the board hasn't finalized the funding formula it wants to use, Burns presented a draft model that would raise the amount of county dollars from $300.7 million this fiscal year to $552 million by the 2013-14 fiscal year.

Bryan said that $552 million figure would require a significant tax increase.

School board members are also concerned about losing control over school construction.

School board member Lori Millberg argued that the school board can't trust commissioners. She pointed to how commissioners had supported converting schools to a year-round calendar as part of a 2006 bond issue before turning on the school district when parents objected.

"I don't feel we can turn over $2 billion in school construction based on trust when there is no trust," Millberg said.

Gill suggested that her colleagues put in writing their thoughts on turning over school construction to the county. She wants these comments turned in by next week so they can discuss them during a board meeting June 17.

That's one day after commissioners are scheduled to vote on their budget.

Ann Denlinger, president of the Wake Education Partnership, had urged commissioners on Monday to delay voting on the budget until June 30 to allow the school board more time to consider her group's plan.

Bryan said they may delay the vote. But he stressed that the school board has to agree to turn over school construction.

"It's not an either-or proposition," Bryan said. "It's a package."