 NEW YORK--BUSINESS WIRE--Blackstone Mortgage Trust, Inc. NYSE:BXMT today announced the closing of its underwritten public offering of its class A common stock. A total of 10,000,000 shares of class A common stock was sold. Aggregate net proceeds to the Company from the offering, after deducting estimated offering expenses, were approximately 312 million. The Company also granted the underwriters a 30-day option to purchase up to an additional 1,500,000 shares. The Company intends to use th 