Prince George's County School Superintendent Edward J. Feeney announced last night that he will reject an arbitrator's decision that the schools must review last year's teacher layoffs and rehire, with back pay, those who were fired improperly.

The decision by Feeney is subject to review and possible reversal by the County Board of Education. The county teachers' union is expected to ask for such a review, which would involve a hearing before the board.

The Tuesday ruling by labor arbitrator Seymour Strongin could affect up to 130 reading specialists, librarians, music and physical education teachers who were among 507 teachers laid off last spring in a cost-cutting move.

The arbitrator's ruling involved the method used to determine each teacher's seniority. The school system argued that only a teacher's most recent, continuous service in teaching a subject should be counted, excluding experience gained earlier.

Strongin said that under the teachers' contract the school system must recognize state-certified training to teach a particular subject area, for instance, secondary mathematics, even if the teacher holding that certificate has been teaching another subject. A teacher whose seniority was figured with that criterion would be allowed to replace or "bump" a less-tenured secondary math teacher, under the ruling.

In a statement to the school board, Feeney said Strongin's ruling would violate existing board personnel policy and added that it would "result in a total defacement of critical personnel policy" and cause chaos in the assignment of personnel.

Under the union contract, arbitration decisions are not binding if it is determined that they violate board policy. Feeney promised to provide details of the policy violations he perceives by June 23.

Union President John Sisson said he was "shocked and surprised" at Feeney's decision.

"They made a mistake and now they're trying to cover their tracks," said Sisson, who promised to take the issue to Circuit Court.

The arbitration ruling was in response to a grievance by the union, the Prince George's Educators Association, on behalf of the 130 elementary teachers who believed they should have been allowed to "bump" certain secondary school teachers based on their certification. The ruling requires them to be reinstated with back pay, estimated by the union at $3 million.

According to union executive director Fred Rummage, the decision could reach beyond the 130 teachers and affect any of those laid off who possess dual certification.

School spokesman Brian J. Porter stressed that the board did not base layoffs strictly on certification and seniority.

"Certification is nothing more then meeting the state requirement for the completion of college course work," Porter said. "It does not automatically denote qualification to teach," he said.

Porter pointed to the example of a 20-year elementary school physical education teacher with a math certification "bumping" a certified math teacher with five years' experience teaching that subject.

"I don't see that that would be a disaster, if he were certified in math," said Sisson. "The state of Maryland says the person is certified. Since when does [the local school board] certify teachers?" he added.