BASF has spent almost 150 years expanding its German chemical mothership into an organism the size of Midtown Manhattan, whose intricate web of pipes and interlocking plants use every bit of oil and gas brought in. The boom in U.S. shale gas hands competitors Dow Chemical Co. and DuPont Co. an 8 percent profit advantage because they pay less for natural gas… The U.S. advantage is already showing up in earnings. BASF’s chemical unit saw operating profit decline 35 percent in the second quarter, weighed down by input costs. Dow paid about $1 billion less for its feedstock and energy costs in the period, according to a company presentation… The U.S. shale gas advantage has bigger implications than today’s energy prices, said Oliver Schwarz, a chemicals analyst at Warburg Research GmbH in Hamburg. “What will hurt BASF more than the energy component is that gas prices in America could lead to new chemical production capacity being built up over the next decades,” he said. “The next generation of assets being built because of gas prices could certainly become dangerous to BASF.”