* S&P revises U.S. outlook to 'negative' * Materials, oil fall after China's move to curb liquidity * Greece denies it is seeking debt-restructuring plan * Dow off 1.1 pct, S&P down 1.1 pct, Nasdaq off 1.1 pct
* For up-to-the-minute market news see [STXNEWS/US] (Updates with Texas Instruments results after the bell)
By Ryan Vlastelica
NEW YORK, April 18 (Reuters) - Wall Street fell more than 1 percent on Monday as sovereign debt fears on both sides of the Atlantic and China's monetary tightening hurt the outlook for global economic growth.
However, equities ended off their lows as some analysts said the sell-off was overdone, though the decline was still the largest in a month.
Standard & Poor's revised its outlook on the United States credit rating downward to "negative" on a poor U.S. budget outlook, while China took additional measures to curb liquidity. For details, see [ID:nN18195555]
Meanwhile, financial markets are increasingly convinced that Greece will have to renegotiate the terms of its public debt, though Greek officials denied that some form of restructuring was imminent. [ID:nLDE73H17X]
Four stocks fell for every one that rose on both the New York Stock Exchange and the Nasdaq. In comparison, the reactions of the U.S. Treasury bond and dollar markets were more subdued. See [US/] and [USD/]
"The behavior of the bond market suggests that we could get a rebound in stocks, at least one related to the S&P news," said David Joy, chief market strategist of Columbia Management in Boston, which oversees $347 billion.
The CBOE Volatility Index <.VIX> rose 10.7 percent after earlier climbing as much as 24.5 percent, its largest daily percentage jump since Feb. 22. [ID:nN18212074]
"We're a little surprised that the VIX is as low as it is, since market risks have risen and there's been some complacency," Joy said, adding that Columbia Management had taken some short-term exposure off the table.
The Dow Jones industrial average <.DJI> slid 140.24 points, or 1.14 percent, to 12,201.59. The Standard & Poor's 500 Index <.SPX> declined 14.54 points, or 1.10 percent, to 1,305.14. The Nasdaq Composite Index <.IXIC> dropped 29.27 points, or 1.06 percent, to 2,735.38.
The S&P 500 index fell below 1,300 for the first time since March 24, though it later rebounded above that level. Short-term support is seen near the 1,285 area.
TEXAS INSTRUMENTS FALLS LATE
After the closing bell, Texas Instruments Inc
Texas Instruments warned that its second-quarter revenue would be hurt by interruptions in production due to the quake damage and power-supply disruptions at those two plants in Japan.[ID:nN18221973]
During the regular trading session, volume was low. About 7.83 billion shares traded on the New York Stock Exchange, the American Stock Exchange and Nasdaq, below last year's daily average of 8.47 billion.
As investors move to companies expected to outperform in uncertain economic times, the defensive S&P 500 sectors like utilities <.GSPU> and consumer staples <.GSPS> posted among the smallest losses in Monday's slide.
Citigroup Inc
Mitch Rubin, chief investment officer of RiverPark Advisors in New York, said the day's earnings suggested volatility in the near term.
"Market movement will be driven by earnings, and we've seen a lot of mixed results," Rubin said. "There's been disappointment about bank results."
China raised banks' required reserves on Sunday for the fourth time this year, extending the fight against excessive liquidity and stubbornly high inflation in the world's second-largest economy. [ID:nL3E7FH05Y]
Caterpillar Inc
China's move and the downward revision of the U.S. credit outlook hurt basic materials and crude prices, sending the Reuters/Jefferies CRB index of commodities <.CRB> down 0.9 percent.
Dow component Exxon Mobil Corp