(), the largest private U.S. real estate investor, is in talks with () to double its line of credit for buying single-family rental homes to $1.2 billion, according to two people with knowledge of the negotiations.

Deutsche Bank extended a $600 million line of credit in October to Blackstone to pay for the properties.

The Frankfurt- based lender will lead a group of banks that will contribute an additional $600 million, according to the people, who asked to be identified because the talks are private.