Updated at 4:03 p.m. ET:Stocks gave up an earlier gain and closed Wednesday lower, adding to a sharp decline one day earlier when the Dow suffered its biggest drop in four months.
Earlier in the day, data from China and Boeing earnings eased concerns about sluggish global growth.
The China HSBC Flash Manufacturing Purchasing Managers Index (PMI) showed that growth shrank for a 12th straight month in October, but output was at a three-month high of 49.1 and order books at their most robust since April, signaling a strengthening recovery.
Boeing Co shares climbed after the commercial jet and defense giant reported earnings and raised its full-year 2012 outlook.
In economic news, the Federal Reserve stuck to its plan to keep stimulating the U.S. economy until the job market improves and repeated its vow to keep rates near zero until mid-2015.
In a policy statement after a two-day meeting, the central bank acknowledged hints of strength in the U.S. housing market, but reiterated a pledge to continue supporting growth even as the recovery picks up.
Corporate profits remained in focus after declines on Tuesday. There has been a series of disappointments in the earnings reported so far, particularly in the results of large multinationals.
A total of 43 S&P 500 companies were scheduled to report earnings on Wednesday.
AT&T Inc posted third-quarter revenue that was below analysts' expectations, but its earnings increased from a year earlier.
Dow Chemical Co, the largest chemical maker in the United States, said Tuesday it would cut 5 percent of its workforce and shut 20 plants to counter a slowing global economy.
Eli Lilly and Co reported quarterly earnings and sales below Wall Street expectations, hurt by higher taxes and generic competition for its Zyprexa schizophrenia drug.
EMC Corp slumped after the data-storage equipment maker reported third-quarter earnings that missed analysts' expectations.
With results in from 29 percent of S&P 500 companies, 37 percent have exceeded revenue forecasts, far below the 62 percent average, and just 57.2 percent of the S&P 500 names reporting so far have beaten earnings forecasts, according to Thomson Reuters data through Tuesday morning.
The current reporting season has seen the lowest percentage of companies exceeding estimates since the fourth quarter of 2001.
Reuters contributed to this report.
