Wall Street falls ahead of Fed statement, Yellen comments

U.S. stocks fell on Wednesday ahead of a highly anticipated statement and news conference by the Federal Reserve later in the session, with the Fed seen giving clearer clues on how soon it plans to tighten monetary policy. Shares were off their lows as utilities, expected to suffer if interest rates rise, and energy companies, recently hurt by lower crude prices, were the unexpected leaders of the session. The Fed is assessing if the U.S. economic recovery can hold up against collapsing oil pric