US STOCKS-Wall Street dips after manufacturing data; energy weak
* ISM's factory activity index drops to 49.4 in August
* Jobless claims rise to 263,000 last week vs est. 265,000
* Energy weighs amid supply concerns
* Dow down 0.16 pct, S&P down 0.24 pct, Nasdaq up 0.09 pct (Updates to mid-afternoon, changes byline)
By Chuck Mikolajczak
NEW YORK, Sept 1 (Reuters) - The S&P 500 and the Dow dipped on Thursday after sluggish monthly factory activity data dented optimism about the economy and oil prices declined, as investors exercised caution ahead of a payrolls report on Friday.
A report from the Institute of Supply Management showed U.S. factory activity contracted for the first time in six months in August as new orders and production tumbled, but data on the labor market pointed to a pickup in third quarter economic growth.
Energy shares, down 0.9 percent, also weighed as oil prices declined on worries about a supply glut. U.S. crude was off 3.1 percent at $43.31 a barrel while Brent shed 2.9 percent to $45.52.
"Both the lower oil prices and the ISM show weakness in the economy," said Tim Ghriskey, chief investment officer of Solaris Asset Management in New York. Continuación...