Ford Motor Co (F.N) on Tuesday reported a profit that was less than analysts expected, selling fewer vehicles in North America as it worked to increase production of the redesigned F-150 pickup truck and losing money in South America. The company raised its forecast for North American operating margin to 8.5 percent to 9.5 percent from 8 percent to 9 percent, but highlighted worsening business conditions in South America. “The external environment in South America has deteriorated compared to where we were just a few months ago,” Ford Chief Financial Officer Bob Shanks said to reporters.