Williamsburg, Va.--Ziff-Davis, one of the American Business Press' largest members, will discontinue its membership as of 2000. While ABP President Gordon Hughes II said the move wasn't a surprise, it's a blow given that it follows on the heels of the loss of dues from CMP Media, which has agreed to be acquired by Miller Freeman. As two of the larger ABP members, Ziff-Davis and CMP each paid the maximum dues of $150,000 a year. The $300,000 generated by Ziff-Davis and CMP accounted for nearly 10% of the association's $3.3 million in dues revenue for 1998. ``One of the things we are going to have to do is change the membership footprint. All of that is being rethought,'' Mr. Hughes said. Last year, the ABP allowed online publishers, such as VerticalNet, and business-to-business publishers to join as associate members at a lower rate. Intel Corp. joined as an associate member Monday. Associate members pay lower dues than the longtime publishing members. A strategic task force headed by IDG President-CEO Kelly Conlin is exploring changing the dues and membership structure to accommodate the changed industry landscape wrought by the Internet and mergers and acquisitions.