* June ADP employment number rises to 172,000 vs est 159,000
* Oil price drops; Exxon, Chevron fall
* Dow down 0.6 pct, S&P down 0.5 pct, Nasdaq down 0.04 pct (Updates to late afternoon)
By Marcus E. Howard
July 7 (Reuters) - Wall Street stocks dipped on Thursday as a drop in oil prices dragged down energy shares, while utilities reversed recent gains.
Oil prices fell more than $2 a barrel, wiping out early gains after the U.S. government reported a weekly crude draw that was within analysts' forecasts, while market optimists expected larger declines.
Exxon Mobil and Chevron were down 1.7 percent and 2.1 percent, respectively.
The S&P energy index was down 1.5 percent, while the utilities index was down the most at 1.9 percent after mostly gaining since Britain's vote to leave the European Union. The telecom services index was down 1.8 percent.
Helping to limit declines, labor data increased optimism ahead of the monthly payrolls report, due on Friday.
The ADP national employment report showed that 172,000 jobs were added in the private sector in June, beating economists' expectation of 159,000.
Stocks rose on Wednesday, partly following minutes from the Federal Reserve's June meeting that indicated it will refrain from raising U.S. interest rates soon.
"The one thing that made the Fed nervous was that poor jobs report last month (May)," said Brad McMillan, chief investment officer for Commonwealth Financial in Waltham, Massachusetts.
The weak May report raised concerns about the recovery of the economy and was seen as throwing the Fed off track from its plans to raise rates in the near term.
At 2:45 p.m. ET, the Dow Jones industrial average was down 97.76 points, or 0.55 percent, to 17,820.86, the S&P 500 had lost 9.87 points, or 0.47 percent, to 2,089.86 and the Nasdaq Composite had dropped 1.44 points, or 0.03 percent, to 4,857.73.
Shares of Humana Inc were down 11.1 percent after a source familiar with the situation said the U.S. Department of Justice has significant concerns about Aetna Inc's proposed acquisition of Humana. Aetna shares were down 4.6 percent at $114.72.
PepsiCo's shares rose 1.5 percent to $107.51 after the company reported a better-than-expected second-quarter profit and raised its full-year profit forecast.
Declining issues outnumbered advancing ones on the NYSE by a 1.19-to-1 ratio; on Nasdaq, a 1.07-to-1 ratio favored decliners.
The S&P 500 posted 34 new 52-week highs and one new low; the Nasdaq Composite recorded 58 new highs and 21 new lows. (Additional reporting by Yashaswini Swamynathan in Bengaluru; Editing by Don Sebastian and James Dalgleish)