Fitch Rates $435.7MM Lehman Mortgage Trust P-T Ctfs, 2006-4.

NEW YORK -- Fitch rates Lehman Mortgage Trust (LMT) $435.7 million mortgage pass-through certificates, series 2006-4, as follows:

--$420 million classes 1-A1 through 1-A4, 2-A1, 2-A2, 3-A1, 4-A1, 5-A1, AX1, AX2, AP1, AP2 and R 'AAA';

--$10.2 million class 1B1 and 2B1 'AA';

--$2.99 million class 1B2 and 2B2 'A';

--$2.1 million class 1B3 and 2B3 'BBB';

--$1.5 million class 1B4 and 2B4 'BB';

--$1.1 million class 1B5 and 2B5 'B'.

The Pool 1 'AAA' rating on the senior certificates reflects the 6.50% total credit enhancement provided by the 3.35% class 1B1, the 1.05% class 1B2, the 0.80% class 1B3, the 0.55% class 1B4, and the 0.40% class 1B5, as well as the non-rated 0.35% class 1B6.

The Pool 2 'AAA' rating on the senior certificates reflects the 2.70% total credit enhancement provided by the 1.55% class 2B1, the 0.40% class 2B2, the 0.25% class 2B3, the 0.20% class 2B4, and the 0.15% class 2B5, as well as the non-rated 0.15% class 2B6.

Fitch believes that the amount of credit enhancement will be sufficient to cover credit losses, including limited bankruptcy, fraud and special hazard losses. In addition, the ratings reflect the quality of the mortgage collateral, the strength of the legal and financial structures, and the master servicing capabilities of Aurora Loan Services, Inc. (rated 'RMS1-' by Fitch) and the primary servicing capabilities of IndyMac Bank, F.S.B., Aurora Loan Services LLC and Countrywide Home Loans Servicing LP.

The Pool 1 trust consists of 745 fixed-rate, conventional, first lien residential mortgage loans, substantially all of which have original terms to stated maturity of 30 years. As of the cut-off date (July 1, 2006), the mortgages have an aggregate principal balance of approximately $189,662,967. The mortgage pool has a weighted average original loan-to-value ratio (OLTV) of 70.65%, a weighted average coupon (WAC) of 6.973%, and a weighted average remaining term to maturity (WAM) of 356.

The Pool 2 trust consists of 837 fixed-rate, conventional, first lien residential mortgage loans, substantially all of which have original terms to stated maturity of 15 years. As of the cut-off date (July 1, 2006), the mortgages have an aggregate principal balance of approximately $249,733,050. The mortgage pool has a weighted average OLTV of 62.29%, a WAC of 6.207%, and a WAM of 175.

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 release issued May 1, 2003 entitled 'Fitch Revises Rating Criteria in Wake of Predatory Lending Legislation' available on the Fitch Ratings web site at www.fitchratings.com.

The mortgage loans were primarily originated or acquired by IndyMac Bank, F.S.B, Lehman Brothers Bank, FSB and Countrywide Home Loans, Inc.

Structured Asset Securities Corporation (SASCO), a special purpose corporation, deposited the loans in the trust, which issued the certificates. For federal income tax purposes, an election will be made to treat the trust fund as multiple real estate mortgage investment conduits (REMICs).

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.