NEW YORK CITY-The Blackstone Group has expanded a credit line to buy single-family homes to $2.1 billion from $600 million, it was reported Thursday at Bloomberg.com.

Deutsche Bank AG leads the syndicate of banks, while other lenders include Bank of America, Credit Suisse, Goldman Sachs and JPMorgan Chase, according to the report.

“The deal demonstrates that the market for these types of loans is expanding and maturing as major Wall Street banks become more and more comfortable with the asset class,” Stephen Blevit, an attorney for Sidley Austin LLP who represented Deutsche Bank, tells Bloomberg.

Blackstone has invested $3.5 billion to buy 20,000 single-family rental homes since last year, according to Bloomberg, making the New York-based company the largest investor of its type in the U.S. The firm is rushing to acquire properties as housing prices recover and as demand for rentals increases among people who can't qualify for a mortgage or don't want to own. The firm had been trying to increase the loan to $1.2 billion.

Blackstone declined to comment and Deutsche did not return a call seeking comment.

The single-family home rental business, which has been dominated by small investors, is attracting more institutional capital, Bloomberg notes. American Homes 4 Rent, a Malibu, California-based company headed by Public Storage founder B. Wayne Hughes, has acquired about 10,000 properties. Thomas Barrack's Colony Capital LLC has raised $2.2 billion for home purchases, according to the site.