* TSX falls 16.96 points, or 0.13 percent, to 12,663.75 * Six of 10 main index sectors decline * TransAlta shares fall after declaring force majeure By John Tilak TORONTO, March 26 (Reuters) - Canada's main stock index fell to its lowest level in almost a month on Tuesday, led by weakness in gold producers, as an easing of worries over Cyprus lessened the appeal of gold as a safe haven and weighed on bullion prices. The market, however, received support from data that showed demand for long-lasting U.S. manufactured goods surged in February, suggesting factory activity continued to expand at a moderate pace. Investors tracked unfolding developments in Cyprus, where banks will remain closed until Thursday and will be subject to capital controls to prevent a run on deposits. "Cyprus is still on people's minds. We're going back and forth on that," said Ian Nakamoto, director of research at MacDougall, MacDougall & MacTier. "Is it going to set a precedent for other countries that get into trouble?" The Toronto Stock Exchange's S&P/TSX composite index was down 16.96 points, or 0.13 percent, at 12,663.75, after falling as far as 12,658.34, its lowest point since February 27. Six of the 10 main sectors on the index were in the red. The materials sector, which includes mining stocks, fell 0.8 percent, with gold-mining shares down more than 1 percent. Bullion prices fell on lower demand after Cyprus secured its last-minute bailout deal. Barrick Gold Corp gave back 1.3 percent to C$29.25, and Goldcorp Inc slipped 0.7 percent to C$33.44. Energy shares lost 0.2 percent. TransAlta Corp declared force majeure at its 395-megawatt Keephills 1 power plant in Alberta due to a winding failure in the generator. Shares of the power generation company were down 0.8 percent at C$14.70.