* TSX ends down 31.91 points, or 0.26 pct, at 12,202.04 * Financials, materials shares down; energy shares up By Claire Sibonney TORONTO, Oct 12 (Reuters) - Toronto's main stock index pulled back on Friday and marked its worst weekly performance in four months as worries about the euro zone's crisis strategy, the upcoming U.S. election and slowing global economic growth limited the appeal of riskier assets. Investors failed to be motivated by data showing Americans were the most upbeat they've been in five years, and by earnings reports showing record quarterly profits at JPMorgan Chase and Wells Fargo & Co. Canadian financials, down 0.2 followed their Wall Street peers into negative territory. Bank of Nova Scotia fell 0.5 percent at C$53.22, and Bank of Montreal was off 0.3 percent to C$58.47. "There's a lot of lethargy out there...people are worried about Europe still and the U.S. election is getting closer and closer," said John Kinsey, portfolio manager at Caldwell Securities, noting that the next couple weeks of U.S. earnings will also provide more direction. Weak global demand has heightened concerns over the prospects for corporate earnings growth. As a group, S&P 500 companies' quarterly earnings are expected to fall 3 percent from a year ago, according to Thomson Reuters data, marking the first decline in three years. Helping to push the index lower was a 1.3 percent drop in its materials sector on weak metals and grain prices. Barrick Gold dropped 1.9 percent to C$38.31, and Potash Corp was down 1.5 percent to C$40.82. The Toronto Stock Exchange's S&P/TSX composite index ended down 31.91 points, or 0.26 percent, at 12,202.04. The TSX lost 1.8 percent in the week, its worst weekly performance since June. "Everybody is focusing more on the uncertainty created not only by Europe, but the U.S. fiscal cliff, the upcoming elections in November, all of those I think are larger than the earnings expectations," said John Ing, president of Maison Placements Canada. A potential bailout request from Spain would remove another layer of uncertainty in financial markets and activate the European Central Bank's bond-buying program aimed at lowering borrowing costs for troubled euro zone economies. Energy shares limited the TSX's fall on Friday, edging up 0.2 percent. The rally was limited by a report from the International Energy Agency (IEA) that said ample supply from North America and Iraq, coupled with declining global demand, could lead to an easing of oil prices over the next five years. Canadian Natural Resources rose 0.8 percent to C$30.25, and EnCana Corp gained 0.6 percent to C$21.91.