Tannenbaum himself owns 25% stake in MLSE, but the exact amount he's selling has not yet been disclosed. The assumption is that he would likely retain a larger portion of his stake.
MLSE not only encompasses the Toronto Maple Leafs but also the Toronto Raptors, Toronto FC, the Toronto Argonauts, the Toronto Marlies, the Raptors 905, and Toronto FC II. On top of the fact that they also own the Scotiabank Arena and the OVO Athletic Centre, while having invested in BMO Field, Coca-Cola Coliseum, Ford Performance Centre, and the BMO Training Ground.
The deal has not yet been disclosed or finalized because Rogers and Bell each own an identical 37.5% stake in the company. They have the right of first refusal should they see a need and have the option to acquire any shares being sold. In addition to Rogers and Bell, they will need the approval from the NHL and the NBA as well.
If everything passes through, it will add to the valuation of NHL franchises. Several teams have finally reached the billion-dollar-club in the most recent Forbes list, the Ottawa Senators were sold at a valuation of a billion dollars, and the Tampa Bay Lightning are in the works of selling a stake at a $1.4 billion valuation.