WASHINGTON (Reuters) - U.S. consumer prices increased in December, with households paying more for gasoline, though underlying inflation remained tame as the economy battled a raging COVID-19 pandemic, which has weighed on the labor market and the services industry. The Labor Department said on Wednesday its consumer price index increased 0.4% last month after gaining 0.2% in November. In the 12 months through December the CPI rose 1.4% after increasing 1.2% in November. Economists polled by Reuters had forecast the CPI shooting up 0.4% and rising 1.3% year-on-year.