London Stock Exchange in Toronto merger talks

TMX Group, the operator of the Toronto Stock Exchange, says it is in advanced talks to merge with the London Stock Exchange in a deal that would make it one of the world's largest stock markets.

TMX Group said the merged companies would be co-headquartered in London and Toronto and continue to be overseen by its existing regulatory authorities. Both exchanges are heavily weighted with mining stocks.

The TMX Group is valued at $3bn (£1.86bn), while the London group's value is slightly higher at around $3.25bn. The TMX Group said executives in the new company would be taken from both companies.

TMX Group, which operates Canada's largest exchange, issued the short statement after shares were halted on Tuesday amid reports of merger talks with the London Stock Exchange.

The merger would require Canadian government approval. Prime Minister Stephen Harper's Conservative government blocked BHP Billiton's foreign takeover of Potash Corp. of Saskatchewan last November.

Several exchanges have merged in recent years. The Singapore Exchange Ltd. said in October it would buy Australian counterpart ASX Ltd. for US$8.3bn in a merger of Asia's second-and third-largest trading operators. In addition to the Toronto Stock Exchange, TMX Group also operates the TSX Venture Exchange, Montreal Exchange, Natural Gas Exchange, Boston Options Exchange, Shorcan and Equicom. The London Stock Exchange Group operates the London Stock Exchange and the Italian stock exchange Borsa Italiana.