Citigroup's first-quarter results suggest tough year ahead

Citigroup Inc reported a sharp decline in quarterly profit on Friday, hit by weak revenue, costs related to shrinking businesses, and loans to energy companies that are going bad. On conference calls, executives suggested the pain might not be over by saying the bank is unlikely to meet a key performance target, and that it could $400 million more in credit costs this year than previously thought if oil prices drop by a certain amount. "2016 didn't get off to the start we hoped for," Chief Execu