Knight Landesman, a longtime publisher of Artforum magazine and a power broker in the art world, resigned on Wednesday afternoon October 25 2017, hours after a lawsuit was filed in New York accusing him of sexually harassing at least nine women in episodes that stretched back almost a decade. For decades, Mr. Landesman, 67, had been a pillar of the international art scene, a man-about-town known from the galleries of Manhattan to the Art Basel fair in Switzerland for his primary-colored suits and deep connections in the industry. The brother of the renowned Broadway producer Rocco Landesman, who once served as the head of the National Endowment for the Arts, he started at Artforum in the 1980s and until Wednesday had run the magazine with his three co-publishers, Anthony Korner, Charles Guarino and Danielle McConnell.