The Canadian dollar weakened against the greenback on Tuesday, and the yield on benchmark government debt slipped. The loonie was trading 0.4% lower at C$1.3585 to the greenback, or 73.61 U.S. cents, after trading in a range of 1.3535 to 1.3591. Canadian government 10-year bond yields fell 7.2 basis points to 3.377%. The yield on similar U.S. government benchmark debt fell to 4.2011%. U.S. January crude futures fell 39 cents to $72.65 a barrel on Tuesday.