The asset management giant and prolific real estate investor sought an extension from the bondholders to repay the debt, but they voted against it, the report said on Thursday, citing people familiar with the matter.

"This debt relates to a small portion of the Sponda portfolio. We are disappointed that the Servicer has not advanced our proposal," Blackstone said in an emailed statement on Thursday.

"We continue to have full confidence in the core Sponda portfolio and its management team," the company added.