New York, July 18 (BridgeNews) - U.S. stocks ended lower as investors punished companies that reported disappointing quarterly results or warned of a shortfall in the coming months. Commentary from Federal Reserve Chairman Alan Greenspan, which downplayed a near-term recovery in the economy, also added to the negative tone. The Dow Jones industrial average ended down 36.56 points at 10,569.83 and the Nasdaq Composite index fell 50.94 points to 2016.38.