NEW YORK, June 14 (Xinhua) -- U.S. stocks erased most of early gains on Monday after Greece's sovereign rating was downgraded to junk status.

Moody's Investors Service slashed Greece's government-bond ratings by four notches to Ba1, highest level in junk territory, warning that there was "considerable" uncertainty surrounding the timing and impact of support measures on the country's economic growth.

Stocks reversed early upward trend and fell into negative area following the downgrade. Dow and S&P ended lower, while Nasdaq managed to close basically flat.

A trader works on the floor of the New York Stock Exchange shortly after the opening bell in New York June 14, 2010.

Wall Street opened higher on Monday as latest data showed that euro zone industrial output surged at the highest pace in almost two decades, easing concerns that a slowdown in Europe could curb global growth.

The euro rose against the U.S. dollar, climbing toward 1.23 dollars, which gave equities a boost as investors regarded the 16- nation currency as the indicator of confidence about European economy.

Stocks had rallied for two sessions prior to Monday, which helped the Dow post its first weekly gains in a month amid volatile trading.

The Dow Jones industrial average fell 20.18, or 0.20 percent, to 10,190.89. The Standard & Poor's 500 index dipped 1.97, or 0.18 percent, to 1,089.63 while the Nasdaq inched up 0.36, or 0.02 percent, to 2,243.96.