Ziff-Davis Inc. filed documents with the Securities and Exchange Commission last week for an initial public offering of its exhibition division, Key3Media Group Inc., which produces Comdex and other information technology trade shows. In the IPO, 5 million shares of the company will be offered at $4 to $6 per share, which will raise about $20 million to $30 million for the company. Funds will be used for general corporate purposes or acquisitions, according to the filing. The filing is one of the final moves in Softbank Corp.'s dismantling of integrated media company Ziff-Davis. When the filing is complete, New York-based Ziff-Davis will be a holding company for ZDNet Inc., a technology portal, and Softbank Corp. will own between 45% and 60% of Key3Media Group, depending upon how many stock options are exercised by Key3Media employees.