WaMu Alt-A Classes Downgraded

Four classes of Washington Mutual alternative-A residential mortgage pass-through certificates, WMALT series 2006-3, have been downgraded by Fitch Ratings.The downgrades were as follows: class B-2, from A to BBB and placed on Rating Watch Negative; class B-3, from BBB to BB and placed on Rating Watch Negative; class B-4, from BB to C/DR4; and class B-5, from B to C/DR5 and removed from Rating Watch Negative. The negative rating actions were based on deterioration in the relationship between credit enhancement and expected losses, Fitch said. The collateral for the deals consists primarily of 15- and 30-year, fixed-rate, first-lien mortgages extended to alternative-A borrowers.