The Fairfax County School Board voted unanimously last night to speed the merger of Fort Hunt and Groveton high schools, discontinuing the use of Fort Hunt as a high school this year instead of in 1986, as had been decided two weeks ago.

This means that Fort Hunt's ninth through 11th graders will transfer to nearby Groveton in the fall. The new plan meets with the wishes of the Fort Hunt community, which has long lobbied to make the move at one time.

Under the board's original plan, Fort Hunt's ninth graders would have gone to Groveton in the fall and the rest of the students would have switched in the fall of 1986.

Now Fort Hunt will be converted to an intermediate school in the fall.

The board also decided to consider a new name, mascot and colors for the consolidated school after receiving recommendations, and to integrate the staff at the two schools, taking into account seniority within the school system. School Superintendent William J. Burkholder said most of the combined faculty would probably be able to stay at the new school and that other school jobs in the county would be found for the others.

No mention was made of Groveton Principal Paul G. Douglas, except that he will work until July 1 with Fort Hunt Assistant Principal John Travis to coordinate the merger. School officials have discussed transferring Douglas, a popular principal, to another job.

Board members asked the Mount Vernon Area School Consolidation Advisory Committee to recommend to Burkholder:

* Whether 1986 graduates will be permitted to choose the school name that will appear on their diplomas -- either Fort Hunt or Groveton.

* Whether senior class standings for 1986 should be calculated separately for students of the two schools.

* Whether two valedictorians, one for Fort Hunt and one for Groveton, should be picked for the senior class of 1986.

School officials said the vote two weeks ago to convert Fort Hunt was one of the most difficult the Fairfax board had ever made. It ended months of emotional debate between the Fort Hunt and Groveton communities over whose high school would have to close to solve a problem of declining enrollments in the eastern part of the county.

Last night's decision to accelerate the Fort Hunt-Groveton shift also will speed up the closing of Bryant and Whitman intermediate schools. They will close at the end of this school year instead of a year later.