PotashCorp is a member of Canpotex, a consortium that sells potash overseas. (Canadian Press)

Premier Brad Wall is talking tougher in the debate over the future of Potash Corporation of Saskatchewan, saying any federal approval of the sale should include conditions to protect the province's interests.

Earlier this month, Australian mining giant BHP Billiton made a $38.6-billion US hostile takeover bid for the Saskatoon-based fertilizer company, prompting the government to say it is looking at its options.

Now, Wall is elaborating on the province's position, saying Saskatchewan people own the potash in Saskatchewan's mines and conditions need to be attached to any sale.

He said he's particularly concerned about the future of Canpotex, the consortium that sells the province's potash overseas on behalf of PotashCorp and two other companies, Mosaic and Agrium.

Wall says if that consortium falls apart and miners undercut each other on price, the people of Saskatchewan could suffer.

Typically, the provincial treasury takes in hundreds of millions of dollars in potash revenue every year, money the government spends on health care, education and other services. But lower potash prices would result in lower potash revenues, the province says.

Offer still on table

Wall wondered aloud whether the federal government can require continued Canpotex membership as a condition of approving the deal.

"We're going to need to find the answer," Wall said. "Can Investment Canada, in approving the deal — if they do approve a deal, if in fact a deal comes together ... can they put a condition on there about Canpotex?"

The PotashCorp board has already rejected BHP Billiton's $130 US per share offer, but industry observers say the bid isn't dead yet.

Asked this week if BHP would stay in Canpotex if it acquires PotashCorp, Graham Kerr, president BHP Billiton diamond and specialty products, was not making any promises.

"No, I think we'd have to understand a little bit more about what the province is looking for," Kerr said. "We haven't spoken to them on that particular issue at the moment. We'd obviously have to understand how Canpotex currently works."

Still, while BHP prefers to sell to its own customers, if staying in the consortium helps the company's bottom line, BHP is all for it, Kerr said.