* U.S. manufacturing growth slows in April -ISM
* Merck, MasterCard shares down after results
* U.S. companies hire less, manufacturing growth slows in April
* U.S. Fed expected to maintain $85 bln/month in bond buys
* Indexes: Dow off 0.3 pct, S&P off 0.3 pct, Nasdaq off 0.3 pct
By Angela Moon
NEW YORK, May 1 U.S. stocks fell on Wednesday, weighed by a slew of economic data that suggested weaker-than-expected growth.
Disappointing results from companies including MasterCard and Merck were also weighing on the market. Merck was the biggest decliner on the blue chip Dow index.
U.S. private employers added 119,000 jobs in April, well below economists' expectations, in the latest piece of data to suggest the economy is encountering a soft patch.
Adding to signs the economy cooled as the second quarter got under way, a separate report showed the pace of U.S. manufacturing growth slowed in April as the sector expanded only modestly.
"We have weak ADP, weak ISM and probably less bullish tone on the state of the economy from the Fed later. Basically, we've had six weeks of weakening data but I think this may be a speed bump rather than a trend," said Jack De Gan, chief investment officer of Harbor Advisory.
"If we can overcome this by the end of the day, we are breaking out of an old high and heading into a new (territory)."
The U.S. Federal Reserve, which is holding a two-day policy meeting, announces its latest decision at 2 p.m. EDT (1800 GMT) and the European Central Bank follows on Thursday. The Fed is likely to keep its foot on the stimulus pedal, especially after disappointing economic data.
The Dow Jones industrial average was down 44.71 points, or 0.30 percent, at 14,795.09. The Standard & Poor's 500 Index was down 5.28 points, or 0.33 percent, at 1,592.29. The Nasdaq Composite Index was down 10.11 points, or 0.30 percent, at 3,318.68.
The S&P 500 closed out its sixth straight month of gains, its longest winning streak since September 2009, with investors using any pullback as a buying opportunity.
The benchmark index hit a new intraday high in the last minutes of trading on Tuesday, following a session in which moves were slight as investors found few reasons to extend recent gains.
MasterCard Inc shares were down 1.7 percent at $543.38 after the world's second-largest credit and debit card network reported a higher-than-expected rise in quarterly profit but revenue fell short of the average analyst estimate.
Merck & Co Inc reported lower-than-expected first quarter sales as generic competition hurt demand for its Singulair asthma drug and the stronger dollar hit overseas sales. The stock was down 3.3 percent at $45.46.
Chesapeake Energy Corp reported a quarterly profit that topped Wall Street expectations on Wednesday, helped by lower production expenses and higher oil and natural gas prices. The stock was off 2.3 percent at $19.10.