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White House: Iran preparing to launch attack on Israel

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US job openings rebound in August

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Port strike halts half of ocean shipping

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Indexes: Dow off 0.82%, S&P 500 down 1.14%, Nasdaq off

1.74%

(Updated at 10:21 a.m. ET/1421 GMT)

By Johann M Cherian and Purvi Agarwal

Oct 1 (Reuters) - Wall Street's main indexes slid on

Tuesday as investors turned risk-averse following reports of

geopolitical tensions escalating in the Middle East, while also

assessing data that pointed to a stable labor market.

A White House official said that the United States has

indications that Iran is preparing to imminently launch a

ballistic missile attack against Israel, following which the

benchmark S&P 500 extended losses to a near one-week low.

At 10:21 a.m. the Dow Jones Industrial Average

fell 346.60 points, or 0.82%, to 41,982.02, the S&P 500

lost 65.54 points, or 1.14%, to 5,696.94 and the Nasdaq

Composite lost 316.54 points, or 1.74%, to 17,872.63.

Nine of the 11 S&P 500 sectors trended lower, although a 3%

spike in crude prices aided a 1.5% gain on the energy sector

. The Dow Jones Transport Average tracking airline

stocks dropped 2%.

CBOE's market volatility index, Wall Street's fear gauge,

jumped 3.46 points to a three-week high of 20.19, while

the yield on benchmark Treasury bonds hit session

lows.

Meanwhile, the Labor Department's job openings and labor

turnover (JOLTS) survey showed job openings rose 8.04 million in

August, compared with estimates of 7.66 million, as per

economists polled by Reuters.

Separately, the

Institute for Management Supply's (ISM) report

showed manufacturing activity stood at 47.2 in September,

versus estimates of 47.5.

Traders are now pricing in a 64.6% probability of a 25

bps reduction at the November meeting, compared with over 60%

before the datasets, as per the CME Group's FedWatch Tool.

"The path of the Fed is assumed to be cutting rates

successively that seems to be driving force behind markets.

Until we get into the teeth of earnings, the labor market data

is extraordinarily important," said Keith Buchanan, senior

portfolio manager at GLOBALT Investments.

"There is increased easing of the labor market in a

gradual pace, but it is not necessarily going to thrust us into

a recession in the near term."

Investors will also parse through comments from Fed

presidents Raphael Bostic and Thomas Barkin among others for

their insights on the economy and the monetary policy outlook.

The comments follow Chair Jerome Powell's at a

conference on Monday, where he reiterated that the Fed is likely

to reduce borrowing costs by an additional 50 basis points by

year-end, based on data that pointed to robust consumer spending

and gross domestic income.

Wall Street's three main indexes closed September

higher, bucking a historical trend where equities' performance

have been weak on average during the month. The benchmark S&P

500 and blue-chip Dow notched their fifth straight

month in gains and closed near record highs in the previous

session.

Markets also monitored a port strike on the East Coast and

the Gulf Coast halting the flow of about half the nation's ocean

shipping.

Retailers account for half of all container shipping volumes

and shares of Costco, Walmart ( WMT ) were down 1.3%

and flat, respectively .

Declining issues outnumbered advancers by a 1.77-to-1 ratio

on the NYSE and by a 2.95-to-1 ratio on the Nasdaq.

The S&P 500 posted 29 new 52-week highs and one new

low, while the Nasdaq Composite recorded 38 new highs and 67 new

lows.