* TSX falls 215.21 points, or 1.54 percent, at 13,717.76 * Index down 1.2 percent this week * Eight of 10 main index sectors decline * Manulife has biggest negative influence on market By John Tilak TORONTO, Jan 24 (Reuters) - Canada's main stock index recorded its biggest single-day drop in seven months on Friday as fears over growth in China and expectations that the U.S. Federal Reserve will scale back its stimulus program next week hit emerging-market assets and dented investor sentiment. The fears about how developing markets will handle the Fed rollback, combined with soft economic data from China, pushed down the prices of some commodities, including oil and copper. In turn, the resource-sensitive Toronto Stock Exchange benchmark index fell for a second straight session and ended the week 1.2 percent lower. The index also hit its weakest level in a week. Ahead of Friday's selloff, the market had been gaining steadily since the start of the year and hit a 2-1/2-year high on Thursday. "Markets are at pretty lofty levels and quite stretched. So if you inject a little bit of risk aversion globally, it could lead to a pullback," said Youssef Zohny, portfolio manager at Stenner Investment Partners, a unit of Richardson GMP. He said some of the issues that have been thrown up could be in the spotlight for the next several weeks. The benchmark S&P/TSX composite index was down 215.21 points, or 1.54 percent, at 13,717.76. "It's clearly not positive for Canada because some emerging markets account for a lot of the commodity purchases," said Lorne Steinberg, president of Lorne Steinberg Wealth Management. "One senses the air coming out of the balloon as investors focus on risk," he added. "Sentiment can turn quickly, and that alone can have a self-fulfilling prophecy when it comes to markets." Eight of the 10 main sectors on the index were in the red on Friday. Financials, the index's most heavily weighted sector, gave back 1.6 percent. Manulife Financial Corp slid 4.3 percent to C$20.86 and had the biggest negative influence on the market. Royal Bank of Canada shed 1.3 percent to C$70.49. Shares of energy producers dropped 1.4 percent, with Suncor Energy Inc slipping 2.4 percent to C$36.91. The materials sector, which includes mining stocks, fell 1.9 percent. Potash Corp was down 3.7 percent at C$35.19, and Teck Resources Ltd stumbled 2 percent to C$26.61.