* Private employers add more jobs than expected in Dec - ADP
* Apple briefly dips below $100
* Indexes down: Dow 1.8 pct, S&P 1.6 pct, Nasdaq 1.6 pct (Updates to late afternoon)
By Caroline Valetkevitch
Jan 6 (Reuters) - U.S. stocks extended losses in late trading on Wednesday as energy shares dropped with oil prices and minutes from the last Federal Reserve meeting added to investor concerns about the economy.
Fresh concerns over the impact of a slowdown in China on the global economy and heightened geopolitical concerns also weighed on stocks.
Shares of Apple briefly dipped below $100 for the first time since Aug. 24 and the stock was the biggest drag on both the S&P 500 and Nasdaq. The stock was last down 2.5 percent at $100.16.
The year got off to a shaky start on Monday after weak data from China triggered declines in global markets, with the Dow recording its worst first day of the year since 2008.
Adding to investors' nervousness was North Korea's announcement that it had successfully tested a hydrogen bomb.
Minutes from the last Fed meeting showed policymakers decided to raise interest rates last month after almost all of them gained confidence inflation was poised to rise, but some voiced worries inflation could get stuck at dangerously low levels.
"We're unwinding year-end window dressing, but more importantly the market is getting weaker, not stronger," said Adam Sarhan, chief executive of Sarhan Capital in New York.
"The fact that the Fed began raising rates 7 years into an economic expansion shows that they're disconnected. It's a late-stage move."
At 3:14 p.m., the Dow Jones industrial average was down 302.93 points, or 1.77 percent, to 16,855.73, the S&P 500 had lost 33.09 points, or 1.64 percent, to 1,983.62 and the Nasdaq Composite had dropped 75.76 points, or 1.55 percent, to 4,815.67.
Shares of oil majors Exxon and Chevron were down while the energy index dropped 4 percent as oil prices plunged.
Data earlier in the day showed that private employers added 257,000 jobs, far ahead of the 192,000 increase expected by economists polled by Reuters. The data comes ahead of a more comprehensive non-farm payroll report on Friday.
Declining issues outnumbered advancing ones on the NYSE by 2,440 to 634, for a 3.85-to-1 ratio on the downside; on the Nasdaq, 2,085 issues fell and 726 advanced for a 2.87-to-1 ratio favoring decliners.
The S&P 500 posted 2 new 52-week highs and 45 new lows; the Nasdaq recorded 25 new highs and 119 new lows. (Additional reporting by Tanya Agrawal; Editing by Saumyadeb Chakrabarty and Nick Zieminski)