Milan, January 4 - The Milan bourse closed 3.2% down Monday, dragged down by China and tensions in the Middle East on a Black Monday in Europe and New York which saw its worst opening since 1932. Milan's bellwether FTSE-Mib index closed on 20,733 points. In New York the Dow dipped briefly below the psychologically important threshold of 17,000 points after a 3% fall. London closed 2.39% down, Frankfurt 4.28% off and Paris 2.47% down. Across Europe some 264 billion euros in share value was wiped out.