* Obama to seek congressional authorization for Syria action
* Verizon and Microsoft fall after announcing major deals
* ISM Manufacturing index comes in ahead of expectations
* Indexes up: Dow 0.11 pct, S&P 0.43 pct, Nasdaq 0.68 pct
By Chuck Mikolajczak
NEW YORK, Sept 3 (Reuters) - U.S. stocks advanced on Tuesdayafter U.S. President Barack Obama decided to seek congressionalauthorization before taking military action against Syria, amove that was likely to shelve any strike for at least severaldays.
Indexes pared initial gains, however, after comments fromseveral congressional leaders indicated support for Obama.
Obama, during a meeting with congressional leaders at theWhite House, called for a prompt vote on Capitol Hill andreiterated that the U.S. plan would be limited in scope and notrepeat the long U.S. wars in Iraq and Afghanistan.
Both John Boehner, the Republican speaker of the U.S. Houseof Representatives, and Eric Cantor, the House Republicanmajority leader, said they would support President BarackObama's call for military action in Syria. Boehner urged hiscolleagues in Congress to do the same.
Nancy Pelosi, Democratic leader in the House ofRepresentatives, said she believes Congress will support aresolution authorizing the use of U.S. military force againstSyria.
"It's going to go up and down based on the expectations ofwhen it is going to happen, but something is going to happen,"said Uri Landesman, President at Platinum Partners in New York.
"You will see it trade down into the speculation and thenonce it actually happens, assuming it's not too big, you'll seea rally. Sell into the news, buy on the news, essentially."
Equities have recently been pressured by the prospect of aWestern strike against Syria after chemical weapons were used tokill civilians, sending the S&P down 1.8 percent last week.
Congress returns from its summer recess on Sept. 9, and anyvote to authorize a strike will come after that.
U.S. crude futures edged up 0.3 percent. Oil spiked2.5 percent in August, largely driven by concerns that militaryaction in the Middle East would disrupt crude supplies.
The Dow Jones industrial average rose 17.01 points or0.11 percent, to 14,827.32, the S&P 500 gained 6.95points or 0.43 percent, to 1,639.92 and the Nasdaq Composite added 24.317 points or 0.68 percent, to 3,614.185.
Verizon Communications agreed on Monday to pay $130billion to buy Vodafone Group out of its U.S.wireless business, bringing an end to an often tense 14-yearmarriage. Verizon lost 2.7 percent to $46.10 while U.S. sharesof Vodafone were flat at $31.45.
Nokia Corp agreed to sell its handset business toMicrosoft Corp for $7.2 billion, sending its U.S.shares up 29.2 percent to $5.04 on record volume. Microsoftfell 6 percent to $31.40 as the biggest drag on the Dow.
In the latest economic data, the Institute for SupplyManagement's August manufacturing index came in at 55.7, aboveexpectations for a reading of 54. July construction spendingrose 0.6 percent, twice the rate that had been expected.
In addition, financial data firm Markit said while its finalU.S. Manufacturing Purchasing Managers Index eased to 53.1 fromJuly's reading of 53.7, a pickup in new orders and a drop ininventories pointed to faster growth ahead.
In the S&P, investors were watching the 100-day movingaverage at 1,639.42, which the index has been unable to closeabove since Aug. 26. Holding over that level would be a positivesign of near-term momentum.
CBS Corp on Monday reached an agreement with TimeWarner Cable Inc to end a month-long blackout of itsstations in New York, Los Angeles and Dallas. Financial terms ofthe deal were not disclosed. Shares of CBS rose 4 percent to$53.16 while Time Warner Cable added 1.6 percent to $109.02.
Vodafone (VOD)