The Canadian provinces of Manitoba, New Brunswick and Quebec have joined Saskatchewan in opposing BHP Billiton's $39 billion takeover bid for Potash Corp, a spokeswoman for Saskatchewan Premier Brad Wall said on Friday.

New Brunswick is the only province outside Saskatchewan with a Potash Corp mine.

The premier of Alberta sided with Saskatchewan earlier this week. Saskatchewan wants Ottawa to reject BHP's bid on the grounds that it is not of net benefit to Canada.