US stocks opened slightly lower Wednesday ahead of a Federal Reserve policy announcement as investors hoped the Fed would take additional stimulus measures to boost the flagging economy.
After five minutes of trade, the Dow Jones Industrial Average was down 8.55 points, or 0.07 percent, at 12,828.78.
The S&P 500-stock index slipped 1.71 (0.13 percent) to 1,356.27, while the tech-rich Nasdaq fell 3.84 (0.13 percent) to 2,925.92.
"The market is likely to go into a holding pattern ahead of the Fed announcement this afternoon. Then, it will all depend on what the Fed says," said Dick Green at Briefing.com.
The central bank's Federal Open Market Committee wraps up a two-day meeting later Wednesday with a policy statement, updated economic forecasts and a news conference with Fed Chairman Ben Bernanke.
Market expectations that the Fed will provide further liquidity to the economy, by extending its stock-swap program that is due to expire at month's-end, have bolstered Wall Street in recent days.
"There is widespread expectation that the Fed will continue Operation Twist. That involves extending the maturity of the Fed's bond portfolio by buying longer-dated issues in place of shorter-term issues," Green said.
On Tuesday, stocks ended solidly higher after a moderately successful Spanish bond auction and on hopes for more Fed stimulus.
The Dow gained 0.75 percent, the S&P 500 advanced 0.98 percent and the Nasdaq added 1.19 percent.