TORONTO — Canada’s competition watchdog and Ontario’s securities regulator on Wednesday approved a bid by a group of Canadian financial institutions to take over the operator of the Toronto Stock Exchange and merge it with two other exchanges.

Maple Group Acquisition Corp. will be permitted to operate a combined exchange and clearing group involving the TMX Group, along with the alternative Alpha Trading Systems Inc. and the Canadian Depository for Securities Ltd.

TMX and Alpha control some 85 percent of all stock trades in Canada, raising some concerns that the merger would give too much power to a single market and clearing operator controlled by Canada’s big financial institutions.