* TSX rises 17.31 points, or 0.14 percent, to 12,757.81 * Seven of 10 main index sectors advance * CN Rail, CP Rail lead the market higher By John Tilak TORONTO, Sept 4 (Reuters) - Canada's main stock index advanced for a second straight session on Wednesday, led by the industrial and financial sectors, with investors encouraged by global economic data and the prospect of only limited military strikes on Syria. Gains were limited as lower gold and crude oil prices weighed on companies that produce those commodities. The Toronto market's benchmark index, which touched a three-month high the previous session, is up about 5 percent for the quarter to date, firming after badly lagging major global indices in the first half of the year. Surveys released on Wednesday showed Chinese service-sector growth reached a five-month high in August and euro zone businesses recorded their best month in August in more than two years. Separate data indicated U.S. auto sales in August rose at their fastest pace in nearly six years. With economic data looking stronger, investors were bracing for the U.S. Federal Reserve to dial back its monetary stimulus program. "The critical piece of the puzzle that the market is looking at is the strength of economic data and the extent to which it bolsters the Fed's case to begin their tapering," said Paul Taylor, chief investment officer at BMO Asset Management. The data suggests that the Fed will begin pulling back on its asset purchases in September, he added. Investors will now turn their focus to Friday's U.S. jobs report, considered by many market strategists as the single biggest indicator of the Fed's monetary direction. The Toronto Stock Exchange's S&P/TSX composite index closed up 17.31 points, or 0.14 percent, at 12,757.81. The market was also preparing for potential tension in Syria as Washington and Russia remained publicly at odds over U.S. plans for a possible military strike. A divided U.S. Senate Foreign Relations Committee on Wednesday approved a resolution authorizing the use of military force in Syria by a vote of 10-7, with one senator merely voting "present." "The biggest issue for investors is the uncertainty, and markets hate uncertainty," said Rick Hutcheon, president and chief operating officer at RKH Investments. "We don't know if the Americans are going to attack, we don't know if anyone is going to do anything." "All this is doing is providing an overlay of uncertainty in a market that is trying to come to terms with the economic realities of the U.S. and European economic recoveries." Seven of the 10 main sectors on the index were higher. Industrials jumped 1 percent. Canadian Pacific Railway Ltd was up 1.8 percent at C$125.97, and Canadian National Railway Co climbed 0.8 percent to C$100.41, playing the biggest role of any two stocks in leading the market higher. Financials, the index's most heavily weighted sector, added 0.2 percent. Bank of Montreal rose 0.3 percent to C$66.80, and Royal Bank of Canada gained 0.1 percent to C$65.48. The materials group, which includes mining stocks, slipped as gold shares fell 0.2 percent. The price of bullion dropped 1.4 percent. Barrick Gold Corp declined 0.6 percent to C$20.40. Energy shares stumbled 0.2 percent, with Suncor Energy Inc down 0.9 percent at C$35.83 and having the biggest negative influence on the market.