Shares of big industrial companies led stocks down, worries about a possible delay in a second Greek bailout package intensified and a middling report on manufacturing in the U.S. Northeast combined Wednesday to curb the markets' enthusiasm for risk.

Adding to the downbeat mood was a report on Iranian TV, later denied by a government agency, that the Islamic republic's nuclear program had made another break-through.

Apple Inc., the world's biggest company by market capitalization, closed down 2.3 percent.

Stocks. The Dow Jones Industrial Average fell 104.14, or 0.81 percent, to 12,774.14 and the broader S&P 500 slipped 7.44, or 0.55 percent, to 1,343.06. Caterpillar, Deere and United Technologies all posted declines of more than one percent. European and Asian equity indexes were mostly up on China's stated intent to assist the struggling Eurozone.

Bonds. The price on the 10-year Treasury rose but slipped modestly after the release of Federal Open Market Committee minutes revealed unanimity among top officials for more ultra-low interest rates but uncertainty about more bond buying.

Currencies. The yen gained on the dollar, but the greenback rose at the expense of the euro, which slipped below $1.32. Brazil's real and Chile's peso fell. 

Commodities. Commodities were mixed. The benchmark U.S. crude oil rose 1.15 percent to $101.90. Gold broke a three-day losing streak, and copper fell for the fourth straight trading day. Most agricultural commodities declined.