US STOCKS-Wall St sharply lower on China fears; NYSE suffers outage
* Stock drop on China market fears
* NYSE resumes trade after three-hour halt
* Wall St maintains losses after Fed minutes
* United Airlines shares fall after computer glitch halts flights
* Indexes close down: Dow 1.47 pct, S&P 1.66 pct, Nasdaq 1.75 pct (Updates close, adds comment and detail on valuations)
By Noel Randewich
July 8 (Reuters) - U.S. stocks ended sharply lower on Wednesday as market turmoil in China eclipsed Greece's debt crisis, while the New York Stock Exchange suffered a major outage.
Fears that a rout in Chinese stocks could seriously harm the country's economy and spread beyond its borders pushed the S&P 500 below its 200-day moving average for the first time since October and into negative territory for 2015.
The NYSE, a unit of Intercontinental Exchange Inc, resumed trade late in the session after a technical problem forced a suspension for more than three hours in the biggest outage to strike a U.S. financial market in nearly two years. Continuación...