* TSX down 94.41 points, or 0.74 percent, at 12,658.09 * All 10 main sectors decline * TD Bank falls after results By John Tilak TORONTO, May 23 (Reuters) - Canada's main stock index dipped on Thursday as fears the U.S. Federal Reserve will dial back its bond-buying program and pessimism following sluggish economic data from China and Europe fueled declines in all major sectors. Weakness in Toronto-Dominion Bank further weighed on the market after the country's No. 2 lender reported earnings slightly below expectations. Investors were nervous after Fed Chairman Ben Bernanke told Congress on Wednesday that a decision to scale back massive bond buying each month could come at one of the U.S. central bank's "next few meetings" if the economy looked set to maintain momentum. The benchmark Canadian index, which tracked weak global markets, eased from gains made in the previous four sessions. "It's the fallout of Ben Bernanke's testimony," said Gavin Graham, chief strategy officer at Integris Pension Management. "That's the first concrete suggestion that maybe they'll reduce the bond buying program." The Toronto Stock Exchange's S&P/TSX composite index closed down 94.41 points, or 0.74 percent, at 12,658.09. "We all know that at some point, the Fed's going to have to do something to withdraw some of that liquidity they put in the marketplace," said Irwin Michael, portfolio manager at ABC Funds. "It's a game of chicken," he added. "People are waiting to find out when, and they will probably react in the short run." Other negative market factors included surveys showing China's factory activity shrank for the first time in seven months in May and that the euro zone economy was likely to contract again in the second quarter. All of the 10 main sectors in the index were in the red. Shares of energy producers fell 0.6 percent. Suncor Energy Inc, Canada's largest energy company, was down 0.6 percent at C$32.32. Financials, the index's most heavily weighted sector, lost 0.4 percent. TD Bank gave back 0.5 percent to C$83.65. The materials sector, which includes mining stocks, was down 0.9 percent despite a rise in shares of gold companies. Miner Teck Resources Ltd fell 4.3 percent to C$28.20, and fertilizer giant Potash Corp slipped 2.1 percent to C$43.01. Among other active stocks, Nordion Inc jumped 11.6 percent to C$8.16 after the major provider of isotopes used in medical imaging said it will sell its targeted therapies division.