The U.S. dollar fell against the euro on Thursday ahead of the European Central Bank's rate decision, as worries about the U.S. economy, higher oil prices and the devastation from Hurricane Katrina continued to weigh heavy. The euro bought $1.2328 in morning European trading, up from $1.2325 in New York the night before. The dollar rose slightly against the Japanese yen, buying 110.81 yen compared with 110.71 on Wednesday, and the British pound dropped to $1.8011 from $1.8016 in New York. Crude oil prices spiked to more than $70 per barrel in the wake of the hurricane that hit the south coast of the United States and damaged some of the production infrastructure. It fell 87 U.S. cents Wednesday to close at $68.94 on the New York Mercantile Exchange, after U.S. Energy Secretary Samuel W. Bodman said the government will release an unspecified amount of oil from its strategic petroleum reserves. The dollar was also hurt Wednesday by a report from the Purchasing Management Association of Chicago that its index of area business activity fell to 49.2 in August on a seasonally adjusted basis from 63.5 in July. A reading above 50 indicates expansion in the manufacturing sector and a reading below 50 indicates a contraction. The U.S. Commerce Department also reported that the U.S. economy grew at a 3.3 percent annual rate in the second quarter, slightly less than the 3.4 percent forecast. Traders were looking past the ECB rate decision, which was widely expected to keep key refinancing rates at 2 percent, to see what the bank said afterward regarding its economic outlook. A U.S. labor market report due Friday was also being closely watched, to see whether it confirms other worries about the American economy.