The Flint Hill School, which was bought in January by a group led by prominent developer John T. "Til" Hazel, is seeking $8.2 million in industrial development bonds through the Fairfax County Economic Development Authority to help pay for the school's new main building.

Although most officials interviewed yesterday said they felt the school's application to the development authority is legitimate, County Board Chairman Audrey Moore said she would oppose it. Moore said she does not feel it is appropriate to use industrial development bonds to pay for construction of a private school.

The bonds would be issued by Signet Bank and would not obligate Fairfax County or the development authority, county officials said. They said the development authority is involved because under state and federal law, such authorities are responsible for vouching that the recipients of the bonds are eligible to receive them.

Commissioners of the development authority, a tax-financed, quasi-governmental agency whose mission is to help attract and retain businesses, voted 5 to 0 to endorse the bonds. With industrial revenue bonds, the school, which is nonprofit and tax exempt, could refinance a construction loan for the new building at about 1 1/2 percent below most commercial lending rates, Hazel said.

The Board of Supervisors, which would need to approve the issuance of any industrial development bonds, will consider the school's application on Monday.

Hazel's association with the school, on Route 123 in Oakton, clearly meant the application would receive heightened attention. He has had numerous run-ins with the board and individual supervisors, particularly Moore, a champion of slowing growth.

Moore said Hazel's involvement was not a factor in her opposition.

"If this were an institution taking care of the mentally retarded or a hospital caring for the sick, I'd have no qualms whatsoever, but this is not in the same vein," Moore said. "This school is in competition with other private schools in the area, and I don't think we can favor one over another."

Hazel said Moore's complaint is not with the school, but with the law. "For years, state statutes have allowed old-age homes, private schools, warehouses and a whole list of things" to be financed with industrial development bonds, he said. "We are doing exactly what we are allowed to do."

A development authority official said there is no limit on the amount of bonds it can endorse for nonprofit entities. He said another private school received $2.9 million in bonds in 1987. Earlier this year, he said, the American Red Cross received $24.2 million in bonds to buy and renovate the AAA Building in Merrifield.