* TSX falls 58.46 points, or 0.48 percent, to 12,180.90 * Goldcorp tumbles 3.1 percent, leading market decline * Saputo up 3.5 percent after announcing U.S. acquisition By John Tilak and Alastair Sharp TORONTO, Dec 3 (Reuters) - Canada's main stock index fell on Monday, led lower by gold mining and financial stocks, after weak U.S. and Canadian manufacturing data raised doubts about the economic outlook. U.S. manufacturing unexpectedly contracted in November, falling to its lowest level in over three years in a sign the sector may be struggling to gain traction, a report from Institute for Supply Management said. "It's the ISM numbers. That is a concern, given how important the health of the U.S. economy is to Canada," said Gavin Graham, president at Graham Investment Strategy. Separately, Canadian manufacturing growth slowed for a fifth straight month in November and hit a more than two-year low, according to the RBC Canadian Manufacturing Purchasing Managers Index. U.S. talks on avoiding the "fiscal cliff" also weighed on the market, given that there did not appear to be keenness to compromise, Graham added. Failure to reach a deal will trigger a combination of U.S. government spending cuts and tax increases in early 2013 that may tip the economy back into recession At mid-afternoon, the Toronto Stock Exchange's S&P/TSX composite index was down 58.46 points, or 0.48 percent, at 12,180.90. Nine of the 10 main sectors declined. Earlier, the index opened higher and hit 12,252.27, its highest point since Nov. 7, after reacting to economic data from China that pointed to the giant Asian economy regaining its vigor after seven straight quarters of slowing growth. The Toronto index's materials sector, which includes the mining stocks, was down nearly 1 percent. Goldcorp Inc tumbled 3.1 percent to C$37.51, and Barrick Gold Corp, fell 1.7 percent to C$33.91, playing the biggest role of any two stocks in leading the market lower. On Monday, Newmont Mining Corp, the world's No.2 gold producer, said chief executive Richard O'Brien will step down on March 1, making it the third major gold miner to announce the departure of its CEO this year. Financials, the biggest sector on the Canadian index, were down 0.5 percent. Bank of Nova Scotia shed 0.8 percent to C$55.57, and Royal Bank of Canada dropped 0.4 percent to C$58.66. The only sector on the index to advance was consumer staples, up 0.8 percent, led higher by dairy products maker Saputo Inc after it said it will buy a U.S. competitor. Saputo's shares rose 3.5 percent to C$47.64.