The Globe and Mail reports in its Wednesday edition that Canada's main stock index ended lower for a fourth straight day as lower commodity prices weighed on resource shares and traders nervously monitored political turmoil in Ottawa. A Reuters dispatch to The Globe says that the S&P/TSX Composite Index ended down 27.50 points at 25,119.71, its lowest closing level since Nov. 20. U.S. stocks posted bigger declines as investors exercised caution ahead of a U.S. Federal Reserve policy announcement on Wednesday. The S&P 500 slid 0.39 per cent. U.S. retail sales increased more than expected in November, buoyed in part by an acceleration in motor-vehicle purchases, consistent with strong underlying momentum in a resilient economy. Canada's annual inflation rate declined to 1.9 per cent in November from 2 per cent in October. Measures of underlying inflation were higher, but money markets continued to lean toward another interest-rate cut by the central bank in January. That kept a weak tone in the Canadian dollar, as did U.S. dollar strength on Tuesday. The Canadian 10-year bond yield eased 4.2 basis points to 3.149 per cent. The price of oil fell 1.6 per cent to $69.57 (U.S.) a barrel on Chinese demand concerns.