Freddie Mac this week issued $1.04 billion of mortgage-backed securities backed by modified loans.The notes are being pooled into new Freddie Mac “Fixed-Rate Modified Participation Certificates” with new "MA-MD" prefixes. The GSE bought the majority of these loans out of participation certificates when they were at least 120 days past due. A Freddie official said that it will not sell the new bonds in the open market and instead will hold them on balance sheet.