TORONTO -- The materials and energy sectors posted losses as Canada's main stock index fell in late-morning trading, while U.S. markets were mixed.

The S&P/TSX composite index was down 40.55 points to 15,175.63, after 90 minutes of trading.

In New York, the Dow Jones industrial average was up 21.91 points to 22,879.62. The S&P 500 index was down 4.55 points to 2,606.07 and the Nasdaq composite index was down 58.59 points to 6,950.22.

The Canadian dollar was trading at 77.58 cents US, down from an average price of 77.71 cents US on Tuesday.

The May crude contract was down 69 cents to US$64.56 per barrel and the May natural gas contract was down one cent to US$2.70 per mmBTU.

The June gold contract was down US$13.40 to US$1,334.50 an ounce and the May copper contract was down one cent to US$2.99 a pound.