San Francisco--CNET Networks Inc. announced Wednesday it has agreed to acquire rival Ziff Davis Inc., including the company's tech portal, ZDNet, in a stock deal initially valued at $1.6 billion. The deal consolidates the two most-visited technology portals into a single company expected to have more than $500 million in combined revenue in 2001. The combined company will have 16.6 million unduplicated unique visitors per month and rank as the eighth-largest property on the Internet, according to Media Metrix figures. Shelby Bonnie will continue as CEO of CNET, and Dan Rosensweig, president and CEO of ZDNet, will become president of the combined company. The reasons these two fierce competitors plan to join forces are many, Bonnie said. He cited strengthening CNET's b-to-b and channel content as a driver in the deal. The combined company will have leading Internet properties in 23 countries, and will boost CNET's presence in Europe. What CNET will offer ZDNet sites, which will continue to operate as their own distinct brands, is a platform for helping businesses and consumers make technology buying decisions. There is about 25% overlap in the top 25 advertisers on each site, Bonnie said, reacting to concerns about CNET and ZDNet having the same marketers as key customers. In addition to ZDNet, CNET also will acquire in the deal Computer Shopper magazine, Smart Planet and Ziff Davis' equity position in Red Herring Communications. The events unit of Ziff Davis, which is being spun off as Key3Media Inc. with an initial public offering slated for August, is not part of this deal.