TSX Group Inc. announced today the appointments of Rik Parkhill, executive vp of TSX Group and president of TSX Markets, and Michael Ptasznik, CFO of TSX Group as interim co-chief executives, effective immediately.

TSX Group CEO Richard Nesbitt announced his resignation earlier today to accept a senior appointment at CIBC World Markets Inc.

TSX Group says Nesbitt has agreed to remain with the organization in an advisory capacity, and as a member of the board, until February 27.

The TSX Group governance committee of the will begin its work to identify a permanent successor to Nesbitt immediately.

Wayne Fox, chairman of the board, will maintain an active dialogue with the co-chief executives during this time.