The Dow Jones Industrial Average was down 7.7 points at 13,301, as 25 of its 30 components traded lower.
Weighing on blue chips, Walt Disney & Co. dropped 1.2% after the entertainment giant didn't generate as much revenue as analysts had forecast, though its 27% profit rise came in ahead of forecast.
International Business Machines , also a Dow component, rose 1.1% after being upgraded to buy from neutral at Goldman Sachs after the technology giant's buyback move.
The S&P 500 index eased back 2.6 points to 1,505, while the Nasdaq Composite lost 15 points to 2,556.
Tech-leader Cisco Systems dropped 5.9% after predicting slowing revenue growth. The networking gear producer reported a 34% profit rise and 21% revenue rise.
Time for pull-back?
Investors are also consolidating some of the market's record gains of the past two months. Through Monday's close, the Dow industrials had matched a 80-year old record of advancing in 24 out of 27 sessions. The average fell back on Tuesday.
"An acceleration in merger-and acquisition activity has caused the stock market to surge higher, despite [slowing] earnings growth and the weaker-than-expected economic outlook," said Bob Doll, global chief investment officer at BlackRock.
"Such divergences are not enough to warrant selling cyclical positions, but they do warn that the recent one-way ride up in equity prices could hit turbulence at any point in time," he said.
Fed clocks in
The Fed is due to announce its interest rate decision at 2:15 p.m. Eastern -- expectations in the market are that rates will be held at 5.25%.
"The market is universally positioned for this, with the only risk being that the Fed may change its language to be a bit more bearish on the economy than the market expects," said Carl Weinberg, chief economist at High Frequency Economics.
Bonds rose slightly, sending yields lower, ahead of the Fed decision. The benchmark 10-year Treasury bond rose 1/32 at 98 31/32, yielding 4.630%.
Crude oil futures were down 10 cents at $62.16 a barrel before weekly inventory numbers.
Gold futures also fell, losing 80 cents to $686.60 an ounce.
On the metals scene, Rio Tinto climbed around 6% in Sydney and London trading on market speculation that the world's number one miner, BHP Billiton , launched a takeover offer. Rio Tinto said it's not aware of any approach.
The Rio Tinto gains come amid a number of consolidation moves in the metals sector, including Alcoa's $27 billion hostile bid for rival aluminum producer Alcan . Previously there has been speculation that Rio or BHP may try to buy Alcoa.
Also on the M&A front, at least three groups of private-equity buyers are circling Alltel , The Wall Street Journal reported Wednesday.
Toyota Motor reported a 9% profit rise on 10% revenue growth in the January-to-March quarter, as U.S. and European sales growth offset flagging sales at home.
Toll Brothers , the luxury home builder, issued another profit warning, noting that tighter lending standards were affecting affordability at lower price points.
Dow Jones is the owner of MarketWatch, the publisher of this report.
By Nick Godt