Fitch Affirms 6 Classes from Wells Fargo Mortgage Backed Securities 2005-4

Business Wire, June 27, 2006

NEW YORK -- Fitch Ratings has affirmed the following ratings from Wells Fargo Mortgage Backed Securities, series 2005-4:

-- Class A affirmed at 'AAA';

-- Class B1 affirmed at 'AA';

-- Class B2 affirmed at 'A';

-- Class B3 affirmed at 'BBB';

-- Class B4 affirmed at 'BB';

-- Class B5 affirmed at 'B'.

The affirmations, affecting approximately $257.65 million in outstanding certificates, reflect adequate levels of credit enhancement relative to expected losses and low seasoning. The pool is seasoned 15 months and has a pool factor of 86%. The transaction has not taken a loss to date, and the serious delinquencies (more than 60 days delinquent, inclusive of foreclosures (FC) and real estate owned (REO)) account for only approximately 56 basis points of the outstanding balance. There are currently no loans in FC or REO.

The mortgage pool consists of fully amortizing, fixed interest rate, first lien mortgage loans, extended to prime borrowers, primarily on one- to four-family properties. All of the loans are master serviced by Wells Fargo Bank, N.A., rated 'RPS1' by Fitch.

Fitch's rating definitions and the terms of use of such ratings are available on the agency's public site, 'www.fitchratings.com'. Published ratings, criteria and methodologies are available from this site, at all times. Fitch's code of conduct, confidentiality, conflicts of interest, affiliate firewall, compliance and other relevant policies and procedures are also available from the 'Code of Conduct' section of this site.