Reuters: U.S. power company Duke Energy Corp (DUK.N: Quote, Profile, Research) on Thursday said it bought wind energy company Catamount Energy Corp from private equity firm Diamond Castle Holdings for about $240 million. Catamount has about 300 megawatts of renewable energy in operation, as well as about 1,750 megawatts of development interest in the United States and the United Kingdom. Duke said the deal price does not include $80 million of assumed debt. Duke bought Tierra …