Attorney General Kathleen G. Kane will not seek to overturn an appellate court ruling that dismissed the most serious charges against three former Pennsylvania State University leaders accused of ignoring or covering up Jerry Sandusky's child sex abuse.

The decision, announced Friday by Kane's office, is a major victory for former Penn State president Graham B. Spanier and top aides Tim Curley and Gary Schultz in a legal battle that has languished for more than four years.

Each was accused of concealing or failing to act on Sandusky's conduct as a serial sex abuser and then lying about it to investigators. But the former administrators contended that the perjury, obstruction, and conspiracy charges against them in 2011 and 2012 were unfairly built on the testimony of Cynthia Baldwin, who was the university's top lawyer during the state investigation of Sandusky, a former assistant football coach.

They argued that Baldwin led them to believe she was representing them, not the institution, when they testified before the Sandusky grand jury - and that she violated attorney-client privilege by becoming a prosecution witness and recounting their conversations and contact.

In January, a three-judge Superior Court panel agreed and threw out those charges. On a petition from Kane's office, the full 12-member Superior Court reconsidered the issue, but upheld the ruling.

Kane's next option was to appeal to the Supreme Court. Instead, she dropped the matter.

In announcing Friday's decision, she said she relied on a legal opinion from her newly appointed solicitor general, Bruce L. Castor Jr.

Castor wrote that because Superior Court opinions are not binding on other cases, it made sense to drop the appeal rather than risk a Supreme Court precedent that could adversely affect the office's ability to use grand juries.

"Should the Supreme Court agree to hear these cases, the resulting decisions would become part of Pennsylvania's common law and would have far-ranging effect on grand jury practice for perhaps decades," he wrote.

It would be "too great a risk to take so long as potentially sustainable charges remain against these defendants."

Kane had previously expressed skepticism about the Sandusky investigation and prosecution, so much so that it helped her win election in 2012. But the decision on whether to appeal was one she could not make herself.

Her own legal troubles - her law license was suspended as she awaits trial on perjury and obstruction charges - had forced her to take a back seat as the Spanier case wended its way through appeals.

The office will still proceed with other charges left intact in the case - including third-degree felony counts of child endangerment.

Elizabeth Ainslie, an attorney for Spanier, could not immediately be reached for comment.

Tom Farrell, an attorney for Schultz, declined to comment on the decision other than to dispute Castor's claim that the Superior Court opinion this year did not set a precedent.

"Now that it is final, it binds all courts in the commonwealth," Farrell wrote in an email.

Others who have defended the administrators Friday celebrated Kane's decision to halt this phase of the fight.

"We are pleased," said Maribeth Roman Schmidt, spokeswoman for Penn Staters for Responsible Stewardship, an alumni organization independent from the university. "We've continually questioned why these Penn State administrators have been made responsible" for errors she said were made by Second Mile, the charity Sandusky used to meet and groom his victims.