LONDON, -- The pit at the International Petroleum Exchange fell silent for good, as the noisy practice of traders in multicolored jackets shouting orders and using hand signals was banished in favor of a fully electronic system. The switch to screen trading of oil futures contracts, which brought an end Thursday to the 25-year tradition of open outcry trading, is part of the IPE's plan to improve efficiency and competitiveness. But the move has also prompted a renewed attack from the New York Mercantile Exchange. The world's biggest energy futures market has set up a rival exchange in Dublin...