A one-time Saskatchewan Crown corporation is the target of a takeover bid by the world's largest mining company.Potash Corporation of Saskatchewan Inc. (PotashCorp), once a Crown corporation in the province until it was sold by the Devine Conservatives in the 1980s, received a takeover offer from BHP Billiton of Australia last week.BHP's first offer was made directly to the board of directors of PotashCorp. After it was rejected, with PotashCorp saying the bid "substantially undervalues" the company, BHP turned directly to the shareholders of the company, offering them $130 per share, making the bid worth approximately $38.6 billion.PotashCorp is currently the world's largest fertilizer producer, while BHP, a mining giant in the world, is making its first foray into the industry with the development of a potash mine near Jansen, south of LeRoy.Some people, including the Sask Party government, have expressed concern about losing head office jobs in the province should BHP take over PotashCorp, but BHP has publicly stated that they will headquarter their potash division in the province. BHP has already opened an office in Saskatoon to oversee the development of the Jansen project.While PotashCorp has Saskatchewan roots and an office in Saskatoon, the head office is in Chicago, where CEO Bill Doyle makes over $6 million a year. The company also has offices, mines, and processing facilities across North America and in countries around the world, including Israel, China, Chile, and Trinidad.BHP holds exploration permits for over 7,388 square kilometres in Saskatchewan.BHP bought out its Anglo Potash Ltd. joint venture in Canada for $282 million in 2008, taking total control of exploration in Saskatchewan. As well, it purchased Athabasca Potash Inc. earlier this year for about $320 million, expanding its potential exploration acreage in Canada to over 14,000 kilometres. The purchase gave BHP rights to the Burr project, just south of Humboldt, which Athabasca had been developing over the past couple of years.Since news of the takeover bid broke, PotashCorp share prices have jumped to just over $150 a share. PotashCorp shares were trading at just over $200 each in mid-2008 before the global recession hit. The company had troubles in 2009, laying off workers at its Saskatchewan mines for most of the year. PotashCorp shares were trading for $88.68 in early July, a 52-week low.Shareholders have until October 19 to decide if they want to accept the BHP offer.