TORONTO - Ontario Finance Minister Dwight Duncan says the Toronto Stock Exchange is a strategic asset in Canada's largest city and decisions about its future must be made in the public interest, not just for shareholders.

The proposed takeover of TMX Group Ltd. (TSX:X) by the London Stock Exchange in what has been called a "merger of equals" requires various approvals, including from Canadian provincial regulators and the federal industry minister.

Industry Minister Tony Clement decided last year to block the US$38.6-billion takeover of Potash Corp. of Saskatchewan (TSX:POT) because it didn't meet the act's test of "net benefit" to Canada.

Clement has provided little detail about his reasons for making that decision, which came after intense lobbying by Saskatchewan Premier Brad Wall, except to say PotashCorp was a strategic asset to Canada.

Duncan reiterated Friday at the Ontario legislature that the province considers the TSX to be strategically important.

"I guess when you announce something like this ... on what I would call a strategically important industry to this country's largest city and largest province, not to mention its impact on Quebec and British Columbia, of course there are political considerations," Duncan said.