* Fed policy statement due at 2:00 p.m. (1800 GMT)
* Adobe, FedEx higher after earnings
* ConAgra slumps after cutting outlook
* Indexes off: Dow 0.22 pct, S&P up 0.03 pct, Nasdaq off 0.11 pct (Updates to midday)
By Chuck Mikolajczak
NEW YORK, June 18 (Reuters) - U.S. stocks held near the unchanged mark on Wednesday, on the heels of a three-day winning streak for the S&P 500 index and ahead of a monetary policy announcement by the Federal Reserve.
The Fed is widely expected to announce another $10 billion cut to its monthly bond purchases as it wraps up a two-day policy meeting at 2:00 p.m. (1800 GMT), but is likely to make few, if any, other concrete policy moves.
Fed Chair Janet Yellen will hold a news conference to discuss the results a half hour later. Investors will be attuned to whether officials may tip their hand on longer-term plans for interest rates.
"The capital markets will be a bit on hold until we get a little bit of detail around the Fed meeting this afternoon and the markets will be closely watching the Yellen press conference that follows today's announcement," said Jim Russell, senior investment strategist at U.S. Bank Wealth Management in Cincinnati, Ohio.
"The Fed will become front and center as a capital market issue as we move through 2014, the taper continues and then the debate towards the fourth quarter begins in earnest regarding actually adjusting the Fed funds rate, we think at some point in 2015."
The benchmark S&P index has risen 0.6 percent over the prior three sessions, as investors largely shrugged off mounting tensions in Iraq amid a flurry of merger and acquisition activity and better-than-anticipated manufacturing data.
U.S. Senate Majority Leader Harry Reid said he does not back sending any U.S. troops into the conflict in Iraq, which he described as a "civil war" on Wednesday ahead of a meeting with President Barack Obama about the escalating crisis.
The Dow Jones industrial average fell 36.48 points or 0.22 percent, to 16,772.01, the S&P 500 lost 0.67 points or 0.03 percent, to 1,941.32 and the Nasdaq Composite dropped 4.96 points or 0.11 percent, to 4,332.28.
Adobe Systems jumped 7.5 percent to $72.62 as the best performer on the S&P 500. The maker of Photoshop and Acrobat software reported better-than-expected quarterly profit and revenue.
FedEx Corp also provided a boost, as shares rose 4.8 percent to $147.03. The world's No. 2 package delivery reported a better-than-expected rise in quarterly revenue on higher volumes in its ground business. The gains helped push the Dow Jones Transportation average up 0.8 percent.
But ConAgra Foods slumped 7.3 percent to $30.45 after the maker of Hunt's tomato ketchup and Slim Jim beef jerky said its adjusted fourth-quarter profit would be lower than expected. (Editing by Bernadette Baum and Nick Zieminski)