TORONTO (Bloomberg) - Canadian stocks fell the most in more than a month, mirroring sell-offs in the US and Asia, as signs that an economic recovery may be weaker than previously estimated held down commodity prices.

Suncor Energy Inc., Canada's largest energy company, dropped four percent after crude oil and gasoline prices fell to two-week lows. Barrick Gold Corp., the world's largest gold producer, lost three percent as bullion slid to the lowest price this month. Royal Bank of Canada, the country's largest lender, declined 2.5 percent, and Manulife Financial Corp., the biggest insurer, sank 3.4 percent.

"People are starting to take a more serious look at market valuations and not liking what they see," said James Bull, who helps manage about C$1 billion in assets as president of Bull Wealth Management Group Inc. in Toronto.

"They're seeing an over-recovery from the overly depressed levels from March."

The Standard & Poor's/TSX Composite Index tumbled 316.42 points, or 2.9 percent, to 10,531.59. The benchmark index had rallied 46 percent from March 9 to August 5 on rebounding commodity prices and economic data indicating the global recession may be ending. It has decreased 4.7 percent since.

All 10 industries in the S&P/TSX declined today. Of 207 stocks in the index, all but 15 fell.

World equities tumbled after foreign direct investment in China fell, Yunnan Copper Industry Co. said there were "no clear signs" of a recovery and Japan's economy grew less than economists estimated, reigniting concern that a five-month, 52 percent rally in developed nations' stock markets was overdone. The MSCI World Index of global stocks dropped 2.7 percent.

"Asian data is critically important to the Canadian market because it is the source of demand for our commodities," said Paul Taylor, chief investment officer of BMO Harris Private Banking, which manages about C$11 billion in assets.

A rise in the US dollar also discouraged investors from buying commodities as a hedge against the currency.

The Dollar Index, which tracks the dollar against a group of world currencies, increased 0.5 percent to the highest level this month.

The Reuters/Jefferies CRB Index of 19 raw materials fell 1.6 percent to a two-week low. Oil, natural gas, gold, copper and silver prices declined.