U.S. consumers are paying the most in six months for gasoline because of declining supplies and rising costs for the ethanol added to the fuel. Prices probably will keep climbing, the largest U.S. motoring group said. Gasoline, averaging $3.561 a gallon at the pump, already costs the most since September, according to AAA. Prices for ethanol, the fuel additive mandated by the government, are the highest in more than seven years after freezing weather and a shortage of rail cars slowed distribution and reduced inventories. Supplies of gasoline were the least since November in the week ended March 28 and demand was 2.2 percent above a year ago during a period of seasonal refinery repairs, according to the Energy Information Administration. Prices for ethanol derived from corn and blended with gasoline at a ratio of at least 10 percent, may extend gains as distillers take plants offline for routine […]