US crude prices were down 0.9 percent at $61.23 a barrel. The recent climb in US Treasury yields helped the greenback gain ground against a basket of major currencies ahead of minutes of the Federal Reserve's most recent policy meeting.
At 9:21 am EST (1421 GMT), the Canadian dollar was trading 0.1 percent lower at C$1.2667 to the greenback, or 78.95 US cents. The currency's strongest level of the session was C$1.2643, while it touched its weakest since February 9 at C$1.2683.
Losses for the loonie came after recent data showed a drop in December manufacturing shipments and wholesale trade, which could dent prospects for monthly gross domestic product. Canada's retail sales report for December is due on Thursday and the country's January inflation report is set for Friday.
Canadian government bond prices were higher across the yield curve in sympathy with US Treasuries. The two-year price rose 2.5 Canadian cents to yield 1.814 percent and the 10-year climbed 15 Canadian cents to yield 2.305 percent. The gap between Canada's 2-year yield and its US equivalent widened by 0.9 of a basis point to a spread of -44.4 basis points, its widest since June 14.