According to Citigroup Inc., BHP Billiton Ltd.’s $40 billion offer for Potash Corp. may not proceed because the bidder is unlikely to overpay and there’s little chance that a competitor will emerge. BHP stock is currently factoring in a bid of about $145 a share, $15 above the current offer. But BHP may need to offer $150 a share to win control of the Saskatoon, Saskatchewan-based Potash Corp. Saskatchewan Premier Brad Wall also isn’t convinced the deal for the world’s largest producer of potash is in the best interests of Canadians. He’s met with the head of global mining giant BHP Billiton but he remains skeptical about the company’s hostile takeover bid. Meanwhile, Prime Minister Stephen Harper says the government will also take a restrained approach to the possibility of a foreign takeover.