A surprise fall in the US unemployment rate to 7.7 percent for November gave markets an initial boost Friday, but the gains were mostly given up later.
At 11:00 (1600 GMT) the Dow Jones Industrial Average was up 26.26 points (0.20 percent) at 13,100.30.
The S&P 500 slipped 0.62 (0.04 percent) to 1,413.32, while the Nasdaq Composite lost 11.31 (0.38 percent) to 2,977.96.
The November jobs market data came in better than expected, the economy adding 146,000 jobs, a gain from October's 138,000, which had been revised downward from the previous report.
The data unexpectedly showed no real effect from Hurricane Sandy, which shut down much of the northeast economy around New York for days at the beginning of November.
Meanwhile, the University of Michigan consumer sentiment index declined to 74.5 from November's 82.7, which had been the best level in five years.
"As we approach the end of the year, there is a risk that fiscal uncertainties might affect further the consumer mood, especially if negotiations on the fiscal cliff continue to stall," said Thomas Julien of Natixis.
Copper miner Freeport-McMoRan, which lost some 20 percent in two days as investors frowned on its deal to buy two related companies at generous prices in deals worth $9 billion, rebounded with a 4.9 percent gain.
Apple shares, volatile all week, fell 1.4 percent.
On the Dow, JPMorgan Chase was the top gainer, up 1.9 percent, while Pfizer led losers off nearly 1.0 percent.
Bond prices fell. The 10-year US Treasury yield rose to 1.60 percent from 1.58 percent Thursday, while the 30-year gained to 2.80 percent from 2.76 percent.
Bond prices and yields move inversely.