US STOCKS-Wall St on track for 3rd day of gains after data
* Jobless claims fall, ISM services index tops forecasts
* Syria in focus after resolution passes Senate committee
* Retailers post Aug sales; Costco beats expectations
* Indexes up: Dow 0.2 pct, S&P 0.3 pct, Nasdaq 0.2 pct
NEW YORK, Sept 5 (Reuters) - U.S. stocks edged higher on Thursday, putting equities on track for a third straight day of gains as a flurry of economic data pointed to improving economic conditions.
Gains were limited, however, with many investors reluctant to make big bets going into Friday's payroll report, and with the prospect of a Western-led strike against Syria still uncertain.
While the data was positive, it did little to alter investor speculation about when the U.S. Federal Reserve might begin to ease its accommodative monetary policies, credited with fueling the equity market's gains in 2013.
"Equities are stuck right now, and there won't be conviction for buyers or sellers until we get more clarity," said Todd Schoenberger, managing partner at LandColt Capital in New York.
The ADP National Employment report showed U.S. private employers added 176,000 jobs in August, nearly matching expectations for a gain of 180,000 jobs, while weekly initial jobless claims fell more than expected to a seasonally adjusted 323,000.
Separately, the Institute for Supply Management's read on the services sector rose more than expected in August, while factory orders fell less than had been anticipated.
The Dow Jones industrial average rose 34.42 points or 0.23 percent, to 14,965.29, the S&P 500 gained 4.12 points or 0.25 percent, to 1,657.2 and the Nasdaq Composite added 7.591 points or 0.21 percent, to 3,656.633.
In a positive sign of near-term upward momentum, the S&P 500 closed above its 100-day moving average for the first time since Aug. 26 on Wednesday. It also closed above its 14-day moving average for the first time since Aug. 8.
After falling 3.1 percent in August, its worst monthly performance since May 2012, the benchmark S&P index has kicked off September with a 1.5 percent advance thus far.
Geopolitical concerns also kept investors on the sidelines after the Senate Foreign Relations Committee backed a resolution for military strikes against Syria in retaliation for a possible chemical weapons attack against civilians.
Market moves have recently been driven by the likelihood of a Western-led strike, with investors attuned to any possible impact on oil supplies.
"Until we have clear certainty on what will happen, it will be hard for the market to focus on anything but Syria for long," said Schoenberger. "Will a war impact what the Fed does? Should we expect oil to go to $140? This is the big issue investors have."
Retail stocks were in focus as the group reports its August sales data. Costco Wholesale Corp reported same-store sales that beat expectations despite lower fuel prices, sending shares up 2.4 percent to $114.20.
In merger news, Otsuka Pharmaceutical agreed to buy U.S. cancer firm Astex Pharmaceuticals for $886 million while Sweden's SKF agreed to acquire Kaydon Corp for $1.25 billion.
Astex rose 2.5 percent to $8.48 while Kaydon jumped 22.3 percent to $35.60.
Ahead of the start of the Group of 20 summit, Russia and China warned that an end to the U.S. Fed's stimulus could have a negative impact on the global economy.
The benchmark 10-year U.S. Treasury note was down 17/32, with the yield at 2.96 percent. Analysts said the rout in Treasuries in recent months could persist.