The Federal Reserve is expected to raise interest rates later in the day.
KEEPING SCORE: The Standard & Poor's 500 index dipped 2 points, or 0.1 percent, to 2,437 as of 11:40 a.m.
The Nasdaq composite added 2 points to 6,222.
The Russell 2000 index sank 8 points, or 0.6 percent, to 1,418.
NextEra Energy, the parent of Florida Power & Light, jumped $1.70, or 1.2 percent, to $141.65 and power company Southern Co.