Alfred Max Loewenthal, 63, assistant to the president of the American Federation of Teachers who was active in labor and civil rights movements in this country and overseas, died Monday at John Hopkins Hospital in Baltimore after surgery for removal of a brain tumor.

Mr. Loewenthal was a full professor of labor history at Rutgers University in 1969 and 1970. He was awarded an honors medal by the university for his innovations in labor education.

He began his career in the late 1930s as a sheetmetal worker for the International Telephone and Telegraph Corp. in his native Newark, N.J.In 1941, he was elected to the executive board of the International Union of Electrical, Radio and Machine Workers (IUE) and subsequently served as shop steward, business agent and education director of the union's District 3, which represents New York and New Jersey.

He was assistant to the president of District 3 before moving to IUE headquarters here in 1955 as assistant to the union's president.

Mr. Loewenthal joined the American Federation of Teachers in 1967. He was an organizer for the union's Local 1 in New York City for a short time before returning to Washington as the AFT's public relations director. He became assistant to the president in 1970.

He traveled all over the world on behalf of the AFT conducting seminars for teachers and other organized workers.

He played a role in obtaining the release of teacher held as political prisoners in South America and Africa and was active in the Histadrut, Israel's labor organization.

Mr. Loewenthal took part in civil rights demonstrations here and in Selma, Ala., and was one of the a coalition of civc, religious and labor leaders credited with easing racial tensions in Newark after rioting there in the late 1960s.

He served on the executive boards of the American Trade Union Council, the National Committee for Labor Israel and the American Jewish Committee. He was a former vice president of the New Jersey Council on Economic Education and the New Jersey State Industrial Union Department.

Mr. Loewenthal lived in Kensington.

Survivors include his wife, the former Eleanor Skolnik, of Kensington; three sons, Michael, of Highland, N.Y., Norman, of Chapel Hill, N.C., and Ted, of New York City; and two brothers, Leo, Montclair, N.J., and Sydney, Cherry Hill, N.J., and four grandchildren.

The family suggests that expressions of sympathy be in the form of contributions to Spanish Refugee Aid Inc., of New York City.