A pirate — and not the roiling seas of the energy business — may have been behind recent sharp changes in course by Atlanta-based Mirant Corp.

The buccaneer was Thomas R. Hudson Jr., who heads Pirate Capital LLC, a Norwalk, Conn.-based hedge fund. After dealing with Hudson, Mirant turned away from a takeover bid of another company and, following Hudson’s demands, announced it would sell its energy businesses in the Caribbean and the Philippines and buy back millions of company shares.