Cheering echoed through Regina’s Legislature late Wednesday as federal industry minister Tony Clement announced he had turned down BHP Billiton’s takeover bid for Potash Corp. of Saskatchewan.”Some decisions can only be taken once and there is no turning back, ever,” he told the national media in Ottawa. “Such is the case today.”Clement said the nearly $40-billion bid “does not present a likely net benefit to Canada.”While the country must always be open for business, potential foreign ownership must satisfy the net benefit test under Investment Canada legislation, he said.The decision becomes final in 30 days.