canadian realestate operating company mainstreet equity corp said monday that it has received authorization to purchase up to 10 of its public float over the course of a oneyear period mainstreet equity said that the toronto stock exchange has accepted its notice of intention to make a normal course issuer bid to buy back up to 477109 shares at fridays closing price of 11311 canadian dollars the equivalent of us8891 the value of the shares would be worth around c54 million the company said the buyback period will begin on june 1 and run until may 31 of next year