Ziff-Davis Publishing Co. and Spot Media Communications on Thursday will announce they are forming an new company to link their separate gaming Web sites into one mega-site. The site will be majority owned by Ziff and managed by SpotMedia. SpotMedia opened GameSpot earlier this year, offering reviews, previews and tips for PC gaming. Ziff offers content from several magazines, including Computer Gaming World, Electronic Gaming Monthly and CyberSports, via its Web site. It also operates Nuke.com, acquired earlier this year with Sendai Publishing.