New York--Ziff-Davis announced Wednesday that it has put itself on the block, retaining Morgan Stanley Dean Witter to explore "strategic alternatives to maximize shareholder value." These alternatives include "strategic alliances, mergers, and the sale or joint venture of all or some of the company's businesses." Tokyo-based Softbank Corp., ZD's majority owner, said it was considering the sale of the company because it wanted to focus on pure Internet operations. In addition to publishing magazines such as PC Magazine and PC Week, Ziff-Davis operates ZDNet, its online division, the Comdex computer trade shows, and ZDTV, a technology cable network. ZD's print ad pages and revenue have declined markedly in the past 18 months as computer advertisers have shifted marketing efforts to television and the Internet. In the first half of 1999, ZD's print ad pages declined 21.49% and its print revenue fell 8.39% compared with the same period in 1998.