ByJohn S. McClenahen U.S. Trade Representative Robert B. Zoellick sits down with his counterparts from more than 100 other countries in Cancn, Mexico later this week to try to reconcile differences, particularly between rich and poor nations, over the issues that should get most emphasis during the current round of world trade negotiations. Those negotiations, under the auspices of the Geneva, Switzerland-based World Trade Organization, include a U.S. proposal for eliminating tariffs worldwide on industrial and consumer goods by 2015. The U.S. and the European Union continue to disagree on several trade-talk matters, including agricultural subsidies and the safety of bio-engineered food. In the meantime, the U.S. continues to negotiate and sign bilateral and regional trade deals. Last week, President George W. Bush signed free-trade agreements with Singapore and Chile. The U.S. is now negotiating free-trade pacts with Australia, Morocco, five Caribbean nations and the South African Customs Union. Negotiations are slated to begin soon with Bahrain and the Dominican Republic. And the administration still intends to conclude a Free Trade Agreement of the Americas by Jan. 1, 2005. The U.S. already has free-trade agreements with Canada and Mexico (NAFTA) and Jordan and Israel.