The three finalists under consideration to become the new Fairfax County school superintendent were identified last night as the heads of large school systems in Birmingham, Southern California and Orange County, Fla.

The three have been invited to Fairfax for interviews, and one will probably be picked within two weeks to succeed S. John Davis, who left the Fairfax school system earlier this year to become Virginia's state superintendent of education.

None of the school systems that the candidates head is larger than the Fairfax County system, which, with 128,000 students, is the largest in the Washington area and 10th largest in the nation.

County School Board Chairman Rodney Page said the finalists are:

Wilmer S. Cody, 42, superintendent of the Birmingham schools since 1972. Educated at Harvard, Cody formerly served as school superintendent in Chapel Hill, N.C. He lived in the Washington area from 1970 to 1972 when he worked as an administrator with the National Institute of Education.

Donald Ingwerson, 46, superintendent of the Orange Unified School District in California where he has served since 1972. Ingwerson received his bachelors and masters degrees from Kansas State Teachers College and his doctorate in education from the University of Wyoming. The unified school district is one of two school systems in Orange County, Calif., near Los Angeles.

L. Lynton Deck, 50, superintendent of schools since 1973 in Orange County, Fla., which includes Orlando. Deck has a bachelor's from Davidson College in North Carolina, a master's from George Peabody College in Nashville and a doctorate in education from Harvard.

Deck and the Orange County School Board came under fire earlier this year when a group of parents accused them of violating "sunshine" laws by holding closed meetings while making decisions about closing schools.

In August, a Florida appeals court ruled the board was in violation of public meeting legislation and ordered the board to reexamine the issue in conjunction with public hearings. Following a recommendation from Deck and the school board attorney, the board appealed the case to the Florida Supreme Court, where it is pending, the Orlando Sentinel Star reported.

Cody, Ingwerson and Deck were selected from a pool of more than 100 applicants in a search that has taken nearly four months. The Fairfax job pays $55,000 a year.