US consumer prices were flat in November as Americans paid less for cars and gasoline, a further sign of a cooldown in inflation that could give the Federal Reserve more room to help a still-weak economy. The Labor Department said Friday the Consumer Price Index was unchanged last month. Economists had expected an increase of 0.1 percent.Prices spiked earlier in the year but the report showed the trend has shifted. Over the past 12 months, prices have risen 3.4 percent. That marked a second monthly decline from a three-year high in September.The report “leaves the Fed ample cover for any additional monetary policy accommodation they may see warranted in the New Year,” said Ian Lyngen, a bond strategist at CRT Capital Group in Stamford, Connecticut.Still , some of the data could give pause to policymakers at the central bank.Outside food and energy , prices climbed a faster-than-expected 0.2 percent. These so-called core prices rose 2.2 percent in the 12 months through November, up from 2.1 percent in October.“Core inflation ... is a bit more persistent than what some people had expected,” said Jeremy Lawson, and economist at BNP Paribas in New York.Economists and investors see inflation slowing further over the coming months, which could help convince the Fed to do more to bring down the country’s 8.6 percent unemployment rate. Prices for US government debt rose slightly as investors saw the data opening the door a bit wider to stimulative Fed action. US stocks rose and the dollar fell against the euro as investors remained on edge over the euro zone’s debt crisis.The US recovery has picked up momentum over the past few months, but the Fed on Tuesday warned that turmoil in Europe still presents a big risk to the US economy and it kept the option of further monetary stimulus on the table. Fed ease still in playIn an appearance before Congress on Friday, New York Federal Reserve Bank President William Dudley defended a decision by the US central bank to provide dollars for banks overseas, warning of the risks of disruptive asset sales if liquidity dried up. “If the access to dollar funding were severely impaired, this would necessitate the abrupt forced sales of dollar assets by these banks, which could seriously disrupt US markets and adversely affect US businesses, consumers and jobs,” he said.A 2.4 percent drop in gasoline prices and a 0.3 percent decline in the cost of new vehicles dragged down overall prices in November. Prices for food rose 0.1 percent, while within the core index, prices for apparel jumped 0.6 percent.Many economists have said the Fed could try to give the economy a bit of help at a meeting on Jan. 24-25 by laying out forecasts for interest rates that could underscore its willingness to keep borrowing costs ultra-low for a prolonged period. The US central bank has held overnight interest rates near zero since December 2008 and has bought $2.3 trillion in government and mortgage-related bonds in a further attempt to stimulate a robust recovery.Some Fed watchers also think the US central bank will step up bond buying later in 2012.