The Canadian dollar weakened against the greenback on Tuesday, and the yield on benchmark government debt slipped. The loonie was trading 0.1% lower at C$1.3673 to the greenback, or 73.14 U.S. cents, after trading in a range of 1.3661 to 1.3691. Canadian government 10-year bond yields fell 3.3 basis points to 3.579%. The yield on similar U.S. government benchmark debt fell to 4.4468%. U.S. June crude futures fell 56 cents to $77.92 a barrel on Tuesday.