The debt consists of six tranches of securities, with ratings ranging from AAA to BB-, according to people familiar with the matter. An interest-only loan backing the CMBS bonds will carry a floating rate, the people said. 

The bonds add to an earlier $2.95 billion of commercial mortgage-backed securities that Blackstone sold in July which were also backed by AIR Communities properties.

A representative for Blackstone declined to comment.

Blackstone struck a deal in April to buy Apartment Income REIT, known as AIR Communities, for $10 billion. It said at the time that it would invest more than $400 million to maintain and bolster the company's portfolio of apartment buildings. 

Issuance of CMBS has been torrid recently, with overall sales this year through Monday of $69.7 billion. Spreads on the debt are wider today than they were at the start of the year, but are still below levels from much of last year when concerns over the credit quality of commercial real estate were widespread.