NEW YORK (MarketWatch) -- Canadian stocks opened lower on Wednesday as losses in the health and financial sectors offset an upbeat report about the U.S. job market. The S&P/TSX Composite Index /zigman2/quotes/205922611/realtime ISPTX 0.00% lost 55.13 points to 12,243.50. Shares of Nordion Inc. tumbled 7.3% after the health-products company posted a quarterly net loss. Laurentian Bank /zigman2/quotes/209831927/delayed CA:LB -0.27% shares dipped 0.7% after the Quebec-based bank said its first-quarter profit dropped 16% and earnings were below analysts' expectations. Among the gainers, Wi-LAN /zigman2/quotes/208205067/delayed CA:WIN 0.00% shares jumped 8.7% on a quarterly dividend hike and strong earnings results for the 2011 fiscal year.