The Prince William County School Board approved unanimously last week the county's participation in a regional high school for science and technology slated to open in Annandale in 1985. School Board Chairman Gerard Cleary signed a formal one-year agreement between the two counties the day after the board met.

The $4,500 tuition for each student will be paid in part by the state, although school spokeswoman Kristy Larson said exact figures were not available. The county will also be responsible for the transportation costs of its students, she said.

Tuition for high school students in Prince William is $3,026 annually.

Cleary hailed the decision as one that is "in line with our progress in allowing each student to perform to his or her fullest capabilities." He lauded Fairfax School Superintendent William J. Burkholder and the Fairfax School Board for their decision to cooperate in creating a state-designated "magnet school," one of four in the state established by Gov. Charles S. Robb.

"Other jurisdictions have a high tax base and can afford to do this, but he Burkholder was willing to take the step," Cleary said.

Prince William will be allotted 16 percent of the space in the new school, or seats for 90 students.

The school will provide qualified students with advanced science and technology courses. Currently the county does not know how many students will be interested in attending. Said Cleary, "Our hope is that parents and students will come forward immediately with applications."

One parent at the meeting expressed concern that the magnet school could create an "elitist group," Cleary said. He said that most parents have been supportive of the science high school concept.