Sharply higher prices at the pump pushed overall consumer prices up at their fastest pace in a year and a half, though core prices, which strip out volatile food and energy costs, barely budged, a government report released on Friday showed.

Overall consumer prices rose a slightly more-than-expected 0.5 percent in December, the Labor Department report said, but retail prices excluding volatile food and energy costs rose just 0.1 percent, in line with expectations.

Compared with the same month a year ago, overall consumer prices rose 1.5 percent, while core consumer prices gained 0.8 percent in 2010, the slowest calendar year pace since the department started keeping records in 1958.

(Reporting by Corbett B. Daly, Editing by Chizu Nomiyama)