Markets Lose Steam as Support Rises for Attack on Syria Stocks on Wall Street advanced on Tuesday after President Obama decided to seek Congressional authorization before taking military action against Syria, a move that was likely to delay any strike for at least several days. Indexes pared initial gains, and the Dow Jones industrial average slilpped into negative territory, however, after comments from several Congressional leaders indicated support for Mr. Obama. In afternoon trading, the Standard & Poor's 500-stock index was up 0.1 percent, the Dow was off 0.1 percent and the Nasdaq composite was 0.2 percent higher. Mr. Obama, during a meeting with Congressional leaders at the White House, called for a prompt vote on Capitol Hill and reiterated that the United States plan would be limited in scope and not repeat the country's long wars in Iraq and Afghanistan. Both John A. Boehner, the Republican speaker of the House, and Eric Cantor, the House Republican majority leader, said they would support the plan, and Mr. Boehner urged his colleagues in Congress to do the same. Nancy Pelosi, Democratic leader in the House, said she believed Congress would support a resolution authorizing the use of military force against Syria. "It's going to go up and down based on the expectations of when 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 then once it actually happens, assuming it's not too big, you'll see a rally. Sell into the news, buy on the news, essentially. Equities have been pressured by the prospect of a Western strike against Syria after a chemical weapons attack killed hundreds of civilians. The geopolitical uncertainty contributed to steep losses in August, which was the worst month for the S.& P. 500 since May 2012. Verizon Communications agreed on Monday to pay $130 billion to buy the Vodafone Group's stake in Verizon's wireless business, bringing an end to an often tense 14-year union. Shares of Verizon, a Dow component, fell 2.7 percent, while United States-traded shares of Vodafone lost 2.9 percent. Also in deal news, Nokia agreed to sell its handset business to Microsoft for $7.2 billion, sending its United States-traded shares up 29 percent. Microsoft fell 6.1 percent. Markets on Wall Street were closed on Monday for Labor Day, and recent light trading volume could continue with many traders away for the holiday. In the S.& P., investors will be watching the 100-day moving average at 1,639.42, which the index has been unable to close above since Aug. 26. Holding over that level would be a positive sign of near-term momentum. While the uncertainty related to Syria has been the market's primary driver in recent sessions, investors will also pay close attention to the latest economic data, which could provide some insight into when the Federal Reserve might begin to slow its monetary stimulus program. In other company news, the CBS Corporation reached an agreement on Monday with Time Warner Cable to end a monthlong blackout of its stations in New York, Los Angeles and Dallas. Financial terms of the deal were not disclosed. Shares of both companies rose: CBS by 4 percent and Time Warner Cable by 1.6 percent. Wall Street stocks have been coming off an extended period of weakness, with all three major indexes falling more than 1 percent last week and posting steep losses in August. Asian markets were broadly higher, with the Nikkei index as the region's standout performer. It surged 3 percent, to a three-week high, helped by a weaker yen, hopes of continued government stimulus and talk that Japan could win the right to host the 2020 Olympic Games. European shares slumped by the end of the trading session, with the FTSEurofirst 300 down 0.4 percent at the bell. American crude oil futures, down earlier in the day, rose 70 cents a barrel, to $108.35, in the afternoon. Oil had risen 2.5 percent in August, with the increase largely driven by concerns that military action in the Middle East would affect crude supplies.