* TSX up 6.34 points, or 0.05 percent, at 12,937.74 * Index touches two-year high * Six of the 10 main index sectors advance * Gold-mining shares decline despite bullion jump By John Tilak TORONTO, Sept 19 (Reuters) - Canada's main stock index was little changed on Thursday as gains in the energy sector offset weakness in gold producers a day after the U.S. Federal Reserve shocked markets by leaving its stimulative bond-buying program in place. The market rallied strongly on the Fed's decision on Wednesday, but on Thursday investors stepped back and tried to dissect the U.S. central bank's comments on the economy and get a sense of how long it can wait before scaling back its stimulus measures. The Fed said it would continue buying bonds at an $85 billion monthly pace, citing strains in the U.S. economy from a tight fiscal policy and higher mortgage rates. That spurred gold-mining shares on the Toronto market to their biggest single-day percentage jump in about four years on Wednesday, but on Thursday they gave back 2 percent despite a 4.3 percent jump in the price of bullion. The fall in golds limited any rises on the benchmark Canadian index although it touched a two-year high in early trading. "It's normal for markets to have an initial, big flurry of action and then take a bit of time to digest the news and consider the ramifications," said Colin Cieszynski, senior market analyst at CMC Markets Canada. "For Canada, it's a case of we would've liked to have seen the U.S. economy growing stronger," he added. "The stronger the U.S. is, the better for us." The Toronto Stock Exchange's S&P/TSX composite index was up 6.34 points, or 0.05 percent, at 12,937.74, after rising as high as 12,964.86, its highest since August 2011. Six of the 10 main sectors on the index were up. Financials, the index's most heavily weighted sector, dropped 0.5 percent. Royal Bank of Canada, the country's biggest lender, declined 0.6 percent to C$65.86. Manulife Financial Corp, an insurer, lost 2.3 percent to C$17.17 and had the biggest negative influence on the index. The materials sector, which includes mining stocks, fell 1 percent. Goldcorp Inc stumbled 1.7 percent to C$28.70, and Barrick Gold Corp was down 2 percent at C$20.25, brushing aside the jump in the gold price. "It suggests that people don't believe the (bullion) rally yet," Cieszynski said. "The Street probably needs more confirmation before they get too excited about the stocks." Shares of energy companies added 0.2 percent. In the group, Canadian Natural Resources Ltd climbed 0.3 percent to C$32.87.