The union that represents Montgomery County teachers has filed a grievance with school officials, protesting their decision to transfer a teacher who reportedly called the Rev. Martin Luther King Jr. a communist.

A union official said that the disciplinary measure violates teacher Karen Collins' rights to free speech.

"The action taken should not have been taken, because she has a right to express her opinion," said Mark Simon, president of the Montgomery County Education Association, which represents 6,400 teachers. "That's not to say that we agree with what she is alleged to have said. We're just trying to ensure there is due process."

He said that the grievance was filed within the last two weeks.

Collins said that she is "very pleased with the support MCEA has given me."

Last month, school officials transferred Collins from Bel Pre Elementary School in Silver Spring to another school and ordered her to enroll in a school system human relations course after they investigated a remark she reputedly had made to another teacher about King. She also received a written reprimand.

Collins has said she told the other teacher that she had reservations about participating in school activities marking the slain civil rights leader's birthday because she "had heard he had communist backing."

Several students who overheard the comment, and the teacher to whom Collins was speaking, have said they heard her say that "King was a communist," according to Roscoe Nix, president of the Montgomery County chapter of the NAACP. The NAACP had asked that Collins be dismissed.

Nix said yesterday he believes that the teachers union had no choice in filing a grievance on Collins' behalf.

"If someone pays dues and they come to you for a grievance, generally you back them," he said.

In a statement issued after Collins was disciplined, Superintendent Wilmer S. Cody said that "while Mrs. Collins has the right to express her personal opinion, her expression casts doubt on her ability to successfully implement the program and goals of this school system."

If the union and the school officials fail to resolve the grievance, Simon said, the issue will go to an outside arbitrator.