TORONTO (Bloomberg) - Canadian stocks fell for the first time in three days, paring the main index's weekly gain, as lower commodity prices dragged down energy and raw-material producers.

EnCana Corp. declined as crude oil futures tumbled the most since 2004. Barrick Gold Corp. and Goldcorp Inc. led mining shares lower on a slide in metals prices. Financial companies advanced after CI Financial Income Fund said it held talks about a merger or acquisition with "a number of parties'.

The Standard & Poor's/TSX Composite Index dropped 0.7 percent to 13,447.29 in Toronto. Canada's benchmark still had its second weekly advance this month, gaining 2.7 percent, as commodity prices rallied through Thursday.

"People are trying to get the right valuations on these commodity stocks," said Greg Eckel, who helps manage about $1.15 billion at Morgan Meighen & Associates in Toronto. "Clearly they went to extremes, both on the upside and the downside."

The S&P/TSX dropped 11 percent from its June 18 record after commodity prices fell on concern financial companies' credit losses will slow global growth and demand for resources, which make up about half of Canada's exports. Measures of energy and raw-materials shares account for 49 percent of the S&P/TSX's value and fell 2.1 percent and 2.3 percent, respectively, yesterday.

EnCana, the nation's largest energy company by market value, declined 2.4 percent to C$75.72. Suncor Energy Inc., the world's second-biggest oil-sands mining company, retreated 2.3 percent to C$60.36 after climbing 16 percent in the previous three sessions.

Canadian Natural Resources Ltd. fell 3.2 percent to C$86.57. Husky Energy Inc., controlled by Hong Kong billionaire Li Ka-shing, slid 3.7 percent to C$46.67.