Europe will supplant the U.S. as the strongest motor of world growth next year, according to the Organisation for Economic Co-operation and Development (OECD), which groups the world's biggest industrial nations. But poor performances by Italy and Germany will still leave Europe performing below its potential. OECD expects the U.S. economy to grow to 3.6% this year and then to fall back to 2% in 2000. Growth in the 15-nation European Union is forecast at 2.4% next year, up from 1.9% in 1999. Ignazio Visco, OECD's chief economist, says: "Even if Europe pushed ahead of it in growth rate, the American economy can afford the luxury of a slow-down. Optimism for Europe is spurred by high levels of consumer confidence and a recovery in its export markets. But Germany and Italy are lagging because they are more vulnerable to emerging market crises and handicapped by regional structural problems.