Europe has reportedly threatened to file a WTO complaint against the U.S. over fees on cargo ships at U.S. ports, further increasing tensions. A letter from European Commission vice president Leon Brittan is reported to say that harbor fees proposed by the U.S. constituted an unfair tax on European shipping lines, container vessels and their cargoes. If a settlement is not reached by Jan. 1, 2000, Brittan said the commission was likely to ask the World Trade Organization (WTO) to take action. The 134-member organization oversees global trading rules.