WASHINGTON (AP) — U.S. consumer prices increased 0.4% in February, the biggest gain in six months, led by a sharp jump in gasoline prices. But core inflation, excluding food and energy, posted a much smaller 0.1% gain, easing fears about a possible sustained acceleration in inflation. The Labor Department said Wednesday that the February advance in its consumer price index followed a 0.3% rise in January and was the largest advance since a similar 0.4% increase in August. Consumer prices are up 1.7% over the past year, a still moderate performance for inflation which is running below the Federal Reserve’s 2% target for price increases. Core inflation, which excludes volatile food and energy, is up just 1.3% for the past 12 months.