U.S. stocks closed lower by nearly 1.5 percent or more on Wednesday as continued concerns about Greece and the extended selloff in the Chinese market weighed on investor sentiment. Stocks briefly trimmed losses as the New York Stock Exchange resumed floor trading after a near-4 hour halt. ( Tweet This )

The Dow Jones industrial average and S&P 500 closed below their 200-day moving averages and are in negative territory for the year.The Nasdaq slipped 1.75 percent, while the Dow transports plunged more than 2 percent.

"I think it's just a combination of things. Greece is still a concern. China is new, and the Fed (is still out there)," said Art Hogan, chief market strategist at Wunderlich Securities. "Energy didn't get a sustained rally either and that's not helping."

The Federal Open Market Committee (FOMC) minutes from the June meeting showed policymakers were concerned about the situation in Greece and China, with most judging that rate hike conditions were not yet achieved.



"I think somewhat notable (is) more talk around Greece and China back then. It's kind of a today story," said Gregory Peters, senior portfolio manager at Prudential Fixed Income. It's "clear that they're anxious to move off the zero band, but I don't think inflation, international news or even the economy will allow them to get there."

"The market is continuing to price out rate hikes. September is priced out. December is priced out more and more so," he said, noting the latest moves in the bond market were more related to China than the United States.

Bond yields held lower, with the 10-year yield (U.S.:US10Y) at 2.21 percent and the 2-year (U.S.:US2Y) at 0.55 percent. The Treasury auctioned $21 billion in 10-year notes at a high yield of 2.225 percent.

The U.S. dollar fell about half a percent against major world currencies as the euro gained to above $1.10.

"What's more important (than the minutes) is Yellen has a speech scheduled for Friday," said Randy Frederick, managing director of trading and derivatives at Charles Schwab. He noted that the minutes do not reflect the drama in Greece and China of the last two weeks.

Fed Chair Janet Yellen speaks at 12:30 p.m. on Friday.

Separately, San Francisco Fed President John Williams said Wednesday in a Reuters report that the U.S. Federal Reserve will likely raise interest rates this year but should only do so when there are firmer signs that inflation is headed back up toward the central bank's 2 percent target.



Read More Market 'glitches' are nothing new

Earlier, trading on the floor of the New York Stock Exchange was briefly suspended in late-morning trade on Wednesday before resuming around 3:10 p.m.

"We've had some technical malfunctions. Some may be related to connectivity with other exchanges. I believe we're going to have a temporary pause certainly in a variety of stocks perhaps floor wide," Art Cashin, director of floor operations at the NYSE, told CNBC earlier, adding that the halt will not cause a move in a particular direction.



Other exchanges, however, continued trading normally. The NYSE later said that all open orders amid the halt would be cancelled.

"What happens with these situations is often you get a sort of residual result. You're all clear or you get caught up to date and there's a little bit of a backlog that pops up somewhere, and it tends to jam things up. So I don't think any of us has quite enough information yet," Cashin added.

U.S. officials also said there were no indications of a cyberattack.

JJ Kinahan, chief strategist at TD Ameritrade, said retail investors weren't much affected by the outage.

"It's a credit to the system overall that we have an outage to a major exchange and things are able to go seamlessly," he said on CNBC.

The Dow Jones industrial average traded about 200 points lower after NYSE trading was halted as the major averages held to their earlier decline. The Nasdaq Composite off more than 1 percent as biotechs plunged more than 2 percent and Apple (AAPL) fell more than 1 percent. The iPhone maker was also one of the worst performing blue chips.

Phil Quartuccio, CEO of Illustro Trading, had hoped the NYSE floor would reopen by 3:00 p.m.

"I think we all walked in this morning worrying about the big Chinese dip and how it will affect us," he said. "I think the market will shake it off."