Thomas Twombly, president of the Anne Arundel County Board of Education, said yesterday that he will not participate in administrative hearings for Northeast High School teachers, "to eliminate any hint of bias."

Mr. Twombly was criticized last year for his remarks about Harry Lentz, a popular social studies teacher and athletic coach at the Pasadena school. The school system had accused Mr. Lentz of sexual harassment.

Mr. Twombly also said some people had questioned whether he could be fair because he had received information, often anonymous, about the Northeast faculty and because he is the Pasadena community's representative on the board. His wife graduated from Northeast.

The decision leaves seven board members to hear the cases of Charles Yocum and Laurie Cook, who are seeking reinstatement after being acquitted of criminal charges that they had sexual relations with students.

Also unresolved is the case of Brandt Schanberger, on paid administrative leave while the school system investigates allegations that he forced a student to engage in a sex act 20 years ago. Police and prosecutors have refused to press charges.