The cartoon appeared in February. News Corp. chairman Rupert Murdoch published an apology in the Post, but civil rights and community organizations demanded further action.
NAACP President and CEO Benjamin Todd Jealous said Wednesday that News Corp. had agreed to form a "diversity community council" that will meet semiannually with company executives.
The council will include members of the NAACP, 100 Black Men of America, the National Action Network and the National Urban League.
The letter also said that the company will include a "diversity statement of commitment" in its annual report.