Production of new CMOs and REMICs backed by agency pass-throughs declined 30 percent in the third quarter of 2004, sinking to $72.6 billion. Freddie Mac remained the largest issuer of agency-backed structured mortgage securities, with $154.8 billion in transaction volume on a year-to-date basis. That was down 16 percent from the same period in 2003, while the overall market dropped 42 percent.