Burger King says bringing back its “Chicken Fries” for a limited time has helped lift sales in the US and Canada by the biggest jump in two years. The Miami-based chain says global sales rose 2.4 per cent at established locations during the third quarter, including a 3.6 per cent increase in the US and Canada. McDonald’s previously reported a 3.3 per cent decline in the US for the same time, citing heightened competition. After factoring one time charges, such as costs r