(For a live blog on the U.S. stock market, click or type LIVE/ in a news window) * Fed promises to keep bond purchases going * Indexes: Dow -0.35%, S&P 500 -0.05%, Nasdaq +0.14% (ReaUpdates following Fed announcement) Dec 16 (Reuters) - Wall Street was mixed on Wednesday, with the Nasdaq hitting a record high as investors awaited a potential fiscal economic stimulus package after the Federal Reserve repeated a pledge to keep its benchmark interest rate near zero. The S&P 500 turned slightly negative after the Fed promised to keep funneling cash into financial markets to fight the recession, even as policymakers’ outlook for next year improved following initial rollout of a coronavirus vaccine. Gains in tech stocks, many of which have benefited from changes in consumer habits because of the pandemic, pushed the Nasdaq to a record high before it trimmed its gains. Investor sentiment has oscillated in recent sessions between optimism about the early distribution of a COVID-19 vaccine and worries about record infection rates in the United States. Despite the pandemic, the S&P 500 has climbed over 14% in 2020. U.S. congressional negotiators were “closing in on” a $900 billion COVID-19 aid bill that will include $600 to $700 stimulus checks and extended unemployment benefits, and Congress could start voting within 24 hours, lawmakers and aides said. Data showed U.S. retail sales fell 1.1% last month from October, as new coronavirus infections and decreasing household income weighed on spending. The Dow Jones Industrial Average was down 0.35% at 30,094.38 points, while the S&P 500 lost 0.05% to 3,692.8. The Nasdaq Composite added 0.14% to 12,612.09. (Additional reporting by Ambar Warrick and Shreyashi Sanyal in Bengaluru; Editing by Aurora Ellis)