(For a Reuters live blog on U.S., UK and European stock markets, click or type LIVE/ in a news window.)*SEC investigating NYSE opening bell glitch*3M slides on downbeat Q1 forecast*J&J falls on sales warning; GE down on weak profit view*Microsoft quarterly results expected shortlyNEW YORK, Jan 24 (Reuters) -The S&P 500 ended slightly lower Tuesday at the close of a rocky session marked by a raft of mixed earnings and a technical malfunction at the opening bell.A spate of NYSE-listed stocks were halted at the top of the session due to an apparent technical malfunction, which caused initial price confusion and prompted an investigation by the U.S. Securities and Exchange Commission (SEC).More than 80 stocks were affected by the glitch, which caused wide swings in opening prices in dozens of stocks, including Walmart Inc and Nike Inc."Everybody’s having computer problems, first the airlines and now it’s the NYSE," said Tim Ghriskey, senior portfolio strategist Ingalls & Snyder in New York. "Seems like it was quickly corrected.""Some of the prints were clearly bad," Ghriskey added. "It was a surprise. Unexpected."All three indexes sputtered near the starting line for much of the session, showing little apparent momentum in either direction.Fourth quarter earnings season is in full swing, with 72 of the companies in the S&P 500 having reported. Of those, 65% have beaten consensus, just a hair below the 66% long-term average, according to Refinitiv.On aggregate, analysts now expect S&P 500 earnings 2.9% below the year-ago quarter, down from the 1.6% year-on-year decline seen on Jan. 1, per Refinitiv."The Fed will take apart earnings reports and look at how the economy is doing, given the rate hikes and other issues out there," Ghriskey said. "We’re getting closer to that point where the Fed sees enough progress in the inflation fight to stop the (interest) rate hikes and that’s why the markets have reacted positively lately."Economic data showed shallower-than-expected contraction in the manufacturing and services sector in the first weeks of the year, suggesting that the Federal Reserve's restrictive interest rates are dampening demand.According to preliminary data, the S&P 500 lost 2.94 points, or 0.07%, to end at 4,016.87 points, while the Nasdaq Composite lost 29.95 points, or 0.26%, to 11,334.47. The Dow Jones Industrial Average rose 102.53 points, or 0.30%, to 33,732.09.Intercontinental Exchange Inc, owner of the New York Stock Exchange, dropped as SEC investigators searched for the cause of Tuesday's opening bell confusion.Alphabet Inc shares dipped after the Justice Department filed a lawsuit against Google for abusing its dominance of the digital advertising business.Johnson & Johnson's profit guidance came in above analyst expectations.Industrial conglomerates 3M Co and General Electric Co both provided underwhelming forward guidance due to inflationary headwinds.3M's shares lost ground, while General Electric posted modest gains.Aerospace/defense companies Lockheed Martin Corp and Raytheon Technologies Corp were a study in contrasts, with the former issuing a disappointing profit forecast and the latter beating estimates on solid travel demand.Shares of Lockheed Martin and Raytheon advanced on the day.Railroad operator Union Pacific Corp missed profit estimates as labor shortages and severe weather delayed shipments. (Reporting by Stephen Culp; Additional reporting by Shreyashi Sanyal and Johann M Cherian in Bengaluru; Editing by Aurora Ellis)