* Allen H. Neuharth, chairman of Gannett Co., has announced his resignation as a member of the Gannett board, effective April 27 at the annual shareholders’ meeting in Chicago. Neuharth, 65, retires as chairman of Gannett on March 31. He will be succeeded by John J. Curley, president and chief executive. Neuharth’s term as a director expires in 1991. Under Gannett’s bylaws, he would be eligible for election to another three-year term at that time. Neuharth said that he is resigning as a director to avoid “inhibiting” his successor or the board by his presence.