(Reuters) - Shares in Kier Group slumped as much as 14% after the British contractor posted an annual loss, as a radical overhaul to cut debt and simplify its structure to dodge the problems that have toppled others in the industry pushed costs higher.Kier, in the middle of a major revamp under a new boss, reported an operating loss of 217 million pounds in the year ended June 30, from a profit of 134 million pounds a year earlier.The company, which has contracts for London's Crossrail project,..