Stocks fell at the open on Wednesday as investors turned cautious before the Federal Reserve's policy decision, due later in the day, tempering optimism from a report that IBM was in talks to buy computer maker Sun Microsystems .

IBM in talks to buy Sun according to WSJ report.

The Dow Jones industrial average <.DJI> dropped 72.32 points, or 0.98 percent, to 7,323.38. The Standard & Poor's 500 Index <.SPX> fell 6.93 points, or 0.89 percent, to 771.19. The Nasdaq Composite Index <.IXIC> slipped 9.87 points, or 0.68 percent, to 1,452.24.

(Reporting by Rodrigo Campos, Editing by Chizu Nomiyama)