CSFB MBS Classes Downgraded

Three tranches from two deals issued by Credit Suisse First Boston Mortgage Securities Corp. in 2002 and 2003 have been downgraded by Moody's Investors Service.The downgrades to the CSFB Mortgage-Backed Pass-Through Certificates deals were as follows: series 2002-AR2, class I-B-1, from Aaa to A1, and class I-B-2, from Baa1 to Ba2; and series 2003-AR12, class IV-M-2, from Baa3 to Ba3. "Although the 2002 and 2003 deals have pool factors of 1.40% and 4.88%, respectively, the ratings were placed under review for downgrade based on existing credit enhancement levels relative to the current projected losses on the underlying pools," Moody's said. "The affected tranches from series 2002-AR2, for instance, are backed by only 24 remaining loans, and the pool factor is less than 2%." The collateral consists chiefly of first-lien, adjustable-rate jumbo A mortgage loans.