When Reform Rabbi Isaac Neuman arrives in East Germany on Sept. 10 he will become the only American rabbi ministering in a communist country on a permanent basis.

His appointment as spiritual leader of the small Jewish community in East Berlin, where his salary will be paid by the government, is the result of a four-year effort spearheaded by the American Jewish Committee.

In the fall of 1983 a commitee-sponsored delegation to Germany became the first American Jewish group to visit East Berlin since World War II. The president of the Jewish community there asked for the committee's help in obtaining a rabbi to conduct High Holy Day services.

In September 1984, the committee arranged for retired Rabbi Ernst Lorge of Chicago, a German native who escaped to the United States in 1936, to conduct Rosh Hashanah services in East Berlin's small synagogue, the first American rabbi to conduct services there.

Last year Rep. William Lehman (D-Fla.) held several meetings with State Department officers and East German officials and helped the committee work out the agreement under which Rabbi Neuman will be East Berlin's first permanent rabbi in 22 years.

Rabbi Neuman, 65, a native of Poland, was imprisoned during World War II in Auschwitz, where his parents, six sisters and brother were killed. He recently retired as spiritual leader of a Reform congregation in Champaign, Ill.

When Neuman arrives in East Germany he will be ministering to a Jewish community numbering fewer than 600.

"I am going because there are Jews who are in need of spiritual service in this place out of which so much evil and destruction once emanated," Neuman said. "It is my joy to try to rebuild and reconstruct and provide for the needs of this Jewish community."