An Alexandria teachers group yesterday voted to neither endorse nor condemn a 7.8 percent salary and benefits increase approved Wednesday by the city's school board.

The executive committee of the Education Association of Alexandria (EAA) had recommended that the group accept the package "with a watchful eye" on certain technical matters affecting relations between teachers and administrators.

Yesterday's vote by about 100 EAA members meeting at Fort Ward Park has no legal effect on the board-mandated increase, the teachers had sought an 8 percent raise.

"We're losing more than we're gaining," said Diane Miller, a physical education teacher who added that inflation would more than overshadow the 7.8 percent increase.

The EAA, which represents 735 of the city's 840 teachers, also passed a resolution vowing to start a work-to-the-rule job action of no more than 24 hours if it becomes frustrated or overly dissatisfied with school administrators.

The group defeated by a 58-to-32 margin a much stronger proposal to begin such an action next Aug. 28, when teachers begin preparations for the fall term. This measure was vigorously opposed by the group's leadership. Val Martin, president of EAA, said that the "threat of a work-to-the-rule action is more effective than the action" itself.

Under such an action, teachers perform only those jobs to which they are specifically assigned, while in school, and do not volunteer to take extra work home.

EAA members at yesterday's meeting also voted to seek greater benefits for the 25 percent of the teacher force who are at their top salary scale. Such people are not helped as much as lower-salaried workers by across-the-board increases, several speakers said.

The Alexandria School board voted unamimously Wednesday to grant teachers a 4.7 percent pay increase, a 2.6 percent annual increase based on years of service, and a 0.5 percent increase in health benefits. The teachers had originally sought a 7 percent salary increase, but Martin later said the group would be willing to settle for combined increases of 8 percent.

The group put off until Tuesday a decision on whether to rescind its call for the resignation of school superintendent John C. Bristol.

In Prince William County last night, the teachers' organization decided to ask its members in September whether to support a job action to protest what they see as inadequate pay raises. The Prince William School Board voted Wednesday night to give the county's 1,800 teachers 7 percent raises.