TSX to force vote on dilutive takeover offers

* 25 percent dilution threshold for company acquisitions

* Rule change effective November 24

TORONTO, Sept 25 (Reuters) - The Toronto Stock Exchange said on Friday it is changing its rules to require a shareholder vote on highly dilutive takeover deals, a move it said strengthens investor rights and brings it in line with other major markets.

Canada's main stock exchange, run by TMX Group Inc (X.TO), said it received approval from the Ontario Securities Commission for the change, effective Nov. 24.

TSX-listed issuers will be required to obtain security holder approval for public company acquisitions that result in share dilution of 25 percent or more of their issued and outstanding securities.

The issue came to a boil in January when the Ontario Securities Commission ordered HudBay Minerals (HBM.TO) to allow shareholders to vote on its takeover of Lundin Mining (LUN.TO). HudBay had planned to issue around 150 million shares to pay for the deal, which was later scrapped.

A two-day OSC hearing that month followed a challenge by merchant bank Jaguar Financial to the TSX's preliminary approval of the deal.

"Today's announcement is in line with many of the world's major exchanges and provides us with an even stronger platform as we work to attract new investors and capital to Toronto Stock Exchange and to Canada," said Kevan Cowan, president, TSX markets and group head of equities.

Public comment on the issue was gathered in the spring of 2009, the exchange said, and the rule approval will be published on the OSC's weekly bulletin. (Reporting by Jennifer Kwan; Editing by Jeffrey Hodgson)