WASHINGTON (AP) — Consumer prices rose last month as the cost of gas increased by the largest amount since June 2009. But outside of energy costs, there was little sign of widespread inflation. The Labor Department says the Consumer Price Index rose 0.5 percent in December, the largest increase in 18 months. About 80 percent of the increase was due to an 8.5 percent rise in the gasoline index, also the sharpest increase in 18 months. Food prices ticked up 0.1 percent in December. High unemployment and a weak economy are keeping prices in check. Last year,
the index rose by 1.5 percent, down from 2.7 percent in 2009. Excluding the volatile food and energy categories, the so-called core index moved up 0.1 percent in December for the second straight month. In the past year, the core index rose by only 0.8 percent.