Fitch Rates SASCO $1.896B Series 2005-WF4.

NEW YORK -- Fitch has rated the Structured Asset Securities Corporation Trust 2005-WF4 mortgage pass-through certificates as follows:

--$1.617 billion classes A1, A2, A3, and A4 'AAA';

--$60.8 million class M1 'AA+';

--$51 million class M2 'AA';

--$33.4 million class M3 'AA-';

--$26.5 million class M4 'A+';

--$22.6 million class M5 'A';

--$21.6 million class M6 'A-';

--$14.7 million class M7 'BBB+';

--$14.7 million class M8 'BBB';

--$14.7 million class M9 'BBB-';

--$19.6 million class B1 'BBB-'.

The 'AAA' rating on the senior certificates reflects the 17.60% total credit enhancement provided by the 3.10% class M1, the 2.60% class M2, the 1.70% class M3, the 1.35% class M4, the 1.15% class M5, the 1.10% class M6, the 0.75% class M7, the 0.75% class M8, the 0.75% class M9, the 1.00% class B1, the 2.10% privately offered class B2, and the 1.25% initial over-collateralization (OC). The class B2 is not rated by Fitch.

All certificates have the benefit of monthly excess cash flow to absorb losses. In addition, the ratings reflect the quality of the loans, the integrity of the transaction's legal structure as well as the capabilities of Wells Fargo Bank, N.A., rated 'RPS1' by Fitch, as servicer, and of U.S. Bank National Association as trustee.

The certificates are supported by two collateral groups. The first group of mortgage loans consists of 2,338 first and second lien, adjustable-rate and fixed-rate, fully amortizing and balloon, mortgage loans. The mortgage balance as of the cut-off date (Nov. 1, 2005) was $180,557,340. Approximately 22.66% of the mortgage loans are fixed-rate mortgage loans and 77.34% are adjustable-rate mortgage loans. The weighted average loan rate is approximately 7.89%. The weighted average remaining term to maturity is 354 months. The average principal balance of the loans is approximately $77,227. The weighted average original loan-to-value (OLTV) ratio is 91.28%. The properties are primarily located in Illinois (8.30%), Florida (7.63%), Wisconsin (6.44%), and Ohio (5.40%).

The second group of mortgage loans consists of 11,539 first and second, lien adjustable-rate and fixed-rate, fully amortizing and balloon, mortgage loans. The mortgage balance as of the cut-off date (Nov. 1, 2005) was $1,781,648,180. Approximately 25.87% of the mortgage loans are fixed-rate mortgage loans and 74.14% are adjustable-rate mortgage loans. The weighted average loan rate is approximately 7.02%. The weighted average remaining term to maturity is 348 months. The average principal balance of the loans is approximately $154,402. The weighted average OLTV ratio is 80.24%. The properties are primarily located in California (15.63%), Maryland (10.91%), Florida (9.81%), Virginia (6.37%), and Illinois (5.71%).

None of the mortgage loans are 'high cost' loans as defined under any local, state or federal laws. For additional information on Fitch's rating criteria regarding predatory lending legislation, please see the press releases issued May 1, 2003 entitled, 'Fitch Revises Rating Criteria in Wake of Predatory Lending Legislation' and Feb. 23, 2005 entitled, 'Fitch Revises RMBS Guidelines for Antipredatory Lending Laws', available on the Fitch Ratings web site at www.fitchratings.com.

The depositor, Structured Asset Securities Corporation, assigned to the trust fund loan-level primary mortgage insurance policies provided by Mortgage Guaranty Insurance Corporation, PMI Mortgage Insurance Co., Republic Mortgage Insurance Company, Radian Guaranty, Triad Guaranty, and United Guaranty Residential Insurance Company. In addition, the trust fund will have acquired loan-level primary mortgage insurance policies from Mortgage Guaranty Insurance Corporation, PMI Mortgage Insurance Co., and Republic Mortgage Insurance Corp prior to closing. Approximately 36.52% of the mortgage loans with OLTVs greater than 80% are covered.

All of the mortgage loans were purchased by the depositor from Lehman Brothers Holdings Inc.

The trust fund will make elections to treat some of its assets as one or more real estate mortgage investment conduits (REMICs) for federal income tax purposes.

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.