* TSX up 35.28 points, or 0.29 percent, at 12,268.76 * China central bank injection helps sentiment * Investors bet that Spain will seek bailout By Alastair Sharp TORONTO, Sept 27 (Reuters) - Canada's main stock index rose on Thursday morning, breaking a five-day fall, as investors cheered moves by China to inject cash into money markets and bet that Spain will ultimately seek a debt bailout that would trigger euro zone stimulative action. The market's materials, energy and financial sectors - which together account for three-quarters of the Toronto Stock Exchange's S&P/TSX composite index - all notched modest gains, helping the index move up 35.28 points, or 0.29 percent, to 12,268.76 by 10:30 a.m. (1430 GMT). "This injection by China is consequential," said Gareth Watson, a vice president for investment management and research at Richardson GMP, referring to a net 365 billion yuan ($58 billion) money-market injection by China's central bank aimed at preventing a short-term liquidity crunch at the country's commercial banks. On Europe, Watson said that investors appeared to be looking beyond street protests against austerity measures in Spain and Greece and assuming that Madrid will eventually request an aid package that would trigger European Central Bank bond-buying. "The market is looking ahead and finding it very difficult to believe Spain will go ahead without asking for a bailout, so we will react today as if it is already in place," Watson said. Illustrating the broad nature of the Toronto index's modest rise, the three gainers with the most impact on Thursday morning were a bank, an oil company and a gold miner. Bank of Nova Scotia rose 0.9 percent to C$54.54, Suncor Energy moved 0.9 percent higher to C$32.31, and Goldcorp gained 1 percent to C$44.76. Weighing on the index, Enbridge Inc dipped 1 percent to C$38.49 after environmental groups sued the government over the pipeline company's contentious Northern Gateway pipeline.