* 158,000 private jobs added in June vs. est. 185,000 -ADP
* Weekly jobless claims rise for third straight week
* Tesla slips after Model S fails to ace some tests
* Indexes down: Dow 0.43 pct, S&P 0.50 pct, Nasdaq 0.50 pct (Updates to early afternoon)
By Tanya Agrawal
July 6 (Reuters) - U.S. stocks were lower in early afternoon trading on Thursday as weak jobs data from the private sector struck a bleak tone for the critical nonfarm payrolls report due on Friday, while investors fretted about rising tension in the Korean peninsula.
The ADP National Employment Report showed private employers added 158,000 jobs in June, below the estimated addition of 185,000, suggesting some cooling in the labor market as it nears full employment.
The report acts as a precursor to monthly nonfarm payrolls data, which includes hiring in both the public and private sectors.
"The market moves significantly on the jobs report. We are expecting to see a little bit of a rebound from last month, but again we didn't get that in the ADP number today which was also expected to be stronger than what it was," said Lindsey Bell, investment strategist at CFRA Research.
Another set of data showed weekly jobless claims rose for the third straight week, with claims climbing to 248,000, above the 243,000 expected.
Bell said ongoing geopolitical worries around North Korea were also adding to the pressure.
The United States said it was ready to use force if need be to stop North Korea's nuclear missile program after the country test launched a ballistic missile that could hit Alaska.
At 12:55 p.m. ET (1655 GMT), the Dow Jones Industrial Average was down 91.72 points, or 0.43 percent, at 21,386.45, the S&P 500 was down 12.28 points, or 0.50 percent, at 2,420.26.
The Nasdaq Composite was down 30.59 points, or 0.5 percent, at 6,120.27.
Ten of the 11 major S&P 500 sectors were lower, with the health sector's 0.98 percent fall topping the list.
UnitedHealth was the biggest drag on the Dow.
Traders are also grappling with comments from some central bankers, who have signalled that they are close to slowing down ultra loose monetary policies, which have supported stocks and bonds.
Those concerns, along with an anticipation that the Federal Reserve will begin unwinding its bond holdings later this year, led to a sell off in bonds, with benchmark yields touching nearly eight-week highs.
Shares of Tesla fell 4.4 percent after the luxury electric carmaker's Model S did not get the top score in certain tests by the Insurance Institute for Highway Safety.
General Electric slipped 3.1 percent after the European Commission accused the company of providing misleading information during a merger deal. The stock was among the top three drags on the S&P.
L Brands slumped 13 percent after the Victoria's Secret owner's June sales came in below expectations.
Declining issues outnumbered advancers on the NYSE by 2,031 to 817. On the Nasdaq, 1,820 issues fell and 945 advanced. (Reporting by Tanya Agrawal in Bengaluru; Editing by Anil D'Silva)