The Canadian dollar weakened against the greenback on Monday, and the yield on benchmark government debt climbed. The loonie was trading 0.2% lower at C$1.3632 to the greenback, or 73.36 U.S. cents, after trading in a range of 1.3601 to 1.3635. Canadian government 10-year bond yields rose 5.9 basis points to 3.625%. The yield on similar U.S. government benchmark debt rose to 4.4492%. U.S. June crude futures fell 67 cents to $79.39 a barrel on Monday.