The Canadian dollar weakened against its US counterpart on Monday as global uncertainty mounted after Greece shut its banks, but losses were limited. At 9:14 am EDT (1314 GMT), the Canadian dollar was trading at C$1.2371 to the greenback, or 80.83 US cents, weaker than the Bank of Canada's official close on Friday of C$1.2315, or 81.20 US cents. The currency's strongest level of the session was C$1.2304, while its weakest was C$1.2380.