The Alexandria School Board voted Wednesday night to require recitation of the Pledge of Allegiance to the flag in all of the city's schools.

Individual students will not be required to stand and recite the pledge or be penalized if they remain silent and seated, but teachers will be required to lead the pledge and teach it. Recitation of the pledge apparently is optional in most other Virginia school systems.

The board declined to consider a proposal by School Superintendent John L. Bristol to also require every Alexandria high school senior to recite the pledge and the words of the National Anthem as a prerequisite for graduation.

The three blacks on the nine-member board voted against the requirement.

John O. Peterson, one of the black members, told the board that, "For 15 years I've had to refrain from saying part of the pledge because of my beliefs, although I have no problems in standing with respect while it is being said."

Peterson said he objected, like many blacks, to the words "one nation . . . indivisible, with liberty and justice for all" because for so long this had not been true of blacks. "I have less difficulty with it today," he said after the vote, "but there are teachers and some students who may object to it."

Michael Mulroney, one of the board's white members, abstained, saying the recitation requirement would be unworkable and cause difficulty for students, teachers and the school administration.

The requirement was proposed by School Board member Wilfred J. Smith, a retired Air Force colonel, and "enthusiastically supported" by Bristol.

In Maryland, a state law requires daily school exercises including recitation of the pledge. But Kenneth Muir, spokesman for Montgomery County schools, said, "It's my guess that it's not a daily occurrence in any of our schools."