US STOCKS-Wall St treads lower as oil weighs on energy stocks
* U.S. crude drops below $45 for first time since Aug. 15
* Exxon, Chevron among top drags on S&P, Dow
* ADP report: 177,000 jobs added in August vs est. 175,000
* Palo Alto drops after disappointing forecast
* Indexes down: Dow 0.64 pct, S&P 0.67 pct, Nasdaq 0.59 pct (Updates to early afternoon)
By Mamidipudi Soumithri and Yashaswini Swamynathan
Aug 31 (Reuters) - Wall Street was down on Wednesday, with the benchmark S&P 500 index marking its biggest decline in four weeks, as a sharp drop in oil prices weighed on energy stocks.
U.S. crude plunged 3.13 percent, falling below the $45 mark for its first time in 12 trading days after data showed a large unexpected weekly build in U.S. crude and distillate stockpiles and a smaller-than-expected draw in gasoline.
The S&P 500 energy index plunged 1.67 percent, making it the biggest decliner among the 10 major S&P 500 indexes. Continuación...