A former lecturer in the Afro-American Studies Department said yesterday that he resigned last fall because of the administration's "discriminatory policy" toward awarding tenure in the department.

A. B. Spellman submitted his resignation as an Afro lecturer in a Nov. 18, 1975, letter to Ewart Guinier, then chairman of the department.

He left the University at the end of the fall term to accept a contract with the National Endowment for the Arts to conduct policy studies.

Spellman said yesterday that the University's policy of joint-tenured appointment in the Afro department was the chief cause for his resignation. Candidates for tenure in Afro must be nominated by Afro and one other department in the University.

In the letter, Spellman singled out the case of Ephraim Isaac, associate professor of Afro-American Studies, as the basis for his belief that "the administration's attitude toward our faculty varies from disrespect to contempt."

An ad hoc committee created last spring to consider candidates for tenure in Afro did not recommend Isaac's bid for tenure. An Afro Department committee issued a report in November alleging that the ad hoc committee did not give Isaac's candidacy "serious consideration."

Spellman's letter of resignationcoincided with the release of the Afro committee's report on November 18.

According to the letter, the experience of Isaac and other Afro colleagues led Spellman to conclude that "for me to try to have a career at Harvard would be about the same as submitting to a voluntary emasculation."

Dean Rosovsky was unavailable for comment on the matter last night.

Spellman began teaching at Harvard in the spring term of 1974, after turning down the chairmanship of the English Department at Rutgers University--Livingston.