Mortgage Guaranty Insurance Corporation

MGIC

250 E. Kilbourn Avenue

P.O. Box 488, Milwaukee, Wisconsin 53201-0488

Endorsement to Mortgage Guaranty Master Policy

Policy Issued To:

Attached to and Forming Part of Master Policy Number:

LaSalle Bank National Association as Trustee for the	12-670-4-3954
Structured Asset Investment Loan Trust Mortgage
Pass-Through Certificates Series 2004-BNC1
135 South LaSalle Street	Effective Date of Endorsement:
Suite 1625	July 1, 2004
Chicago, Illinois 60603

The purpose of this Endorsement is to amend terms and conditions of the Policy to provide for the insurance of Loans which may be in addition to other mortgage guaranty insurance coverage separately in effect for each of such Loans. This Endorsement will apply to all Loans insured under the Policy. To the extent of any inconsistency or conflict between the terms of the Policy and this Endorsement, this Endorsement will control. The terms and conditions of the Policy shall apply to a Loan insured under this Endorsement, but with the Policy amended by adding, deleting, or amending the following terms and conditions, as indicated:

Primary Policy

The following definitions are added to the Policy:

1.30

"Original LTV" means the ratio of the principal balance of a Loan at its origination to the Value of the Property, as calculated according to the Company's standard procedures.

1.31

"Primary Policy" means the policy or guarantee issued by a mortgage guaranty insurance company approved for insurance of mortgage loans sold to either the Federal National Mortgage Association ("Fannie Mae"), or the Federal Home Loan Mortgage Corporation ("Freddie Mac"), which provides the minimum coverage required by Section 5.14 hereof, and under a form of policy approved by Fannie Mae or Freddie Mac and in general use for the mortgage loans sold to Fannie Mae or Freddie Mac, as applicable. Upon the Company's request, from time to time, the Insured shall provide to the Company a copy of the form of each Primary Policy under which it obtains coverage.

1.32

"Per Loan Loss Percentage" means the indicated percentage as set forth for a Loan on the applicable Certificate.

The following additional exclusions from coverage contained in new Sections 4.11 and 4.12 are added to the Policy:

4.11

Coverage Required Under Primary Policy - Any Claim, if for any reason coverage under a Primary Policy described in Section 5.14 was not in effect at the time of conveyance of the Property as described in Section 6.1 of this Policy.

4.12

Payment of the Full Benefit of the Primary Policy - Any portion of any Claim for Loss to the extent the Insured under the related Primary Policy has not received the amount of the full benefit of the percentage option claim payment under the Primary Policy (irrespective of the reason or cause, including insolvency of the Primary Policy insurer or failure of the Insured to comply with the terms and conditions of the Primary Policy), assuming that all the terms and conditions of the Primary Policy were fully complied with.

Section 5.8 is amended by adding a new subparagraph (f) as follows:

A copy of the claim and evidence of the payment of, and any adjustments to, the claim under the Primary Policy, and other information related to such Primary Policy as the Company may reasonably request.

The following additional condition precedent to payment of Claim, in new Section 5.14, is added to the Policy:

5.14

Coverage Required Under Primary Policy - Except as hereinafter provided, the Insured shall have coverage in full force and effect under a Primary Policy at the time of conveyance of the Property as described in Section 6.1 of this Policy, which provides coverage against loss resulting from a Borrower's Default. The Primary Policy shall, as a minimum, provide coverage on the principal amount of the Loan for those Loans as set forth on the applicable Certificate and in at least the coverage percent as set forth on such Certificate.

Coverage of a Loan under a Primary Policy must remain in force until cancellation thereof is required under applicable law.

Section 6.1 is deleted in its entirety and replaced with the following:

The Insured must submit and settle its claim under a Primary Policy before a Claim on such Loan may be filed under this Policy, and the Insured shall file a Claim after, but no later than ninety (90) days following, the conveyance to the Insured of Borrower's Title to the Property, and the settlement of the claim under the Primary Policy, whichever is later. If the Insured is not required to have Borrower's Title to file a Claim for a reason described in Section 5.9, then, for purposes of the preceding requirements in which reference is made to a period of ninety (90) days following the conveyance to the Insured of Borrower's Title to the Property, in lieu of such reference shall be substituted, as applicable, (a) ninety (90) days after the Property is conveyed in a pre-foreclosure sale, at the foreclosure sale, or by exercise of the rights of redemption or (b) the time specified by Section 5.3. If the Insured fails to file a Claim within the applicable time, the Insured will not be entitled to, and the Company will not be obligated for, any payment under this Policy for amounts, including additional interest and expenses, which would otherwise be claimable, but which accrue or are incurred after the ninety (90) day period for filing of a Claim.

If the Insured fails to file a Perfected Claim within one hundred eighty (180) days after the filing of a Claim (or within such longer period of time as the Company may allow in writing), the Insured will no longer be entitled to payment of a Loss and the Company will not be obligated to make any payment under this Policy.

The introduction to Section 6.2 is deleted in its entirety and replaced with the following:

6.2

Calculation of Claim Amount --- Subject to Sections 7.5 and 5.3, and the requirement for a Primary Policy, if any, the Claim Amount will be an amount equal to the sum of:

Section 6.2 is amended by deleting "and" after subparagraph (iv) and inserting "; and" in place of the period at the end of (v), and by adding a new subparagraph (vi) as follows:

(vi).

The greater of the amount of any claim payment pursuant to a Primary Policy which the Insured received, or which the Insured should have received in order for the exclusion under Section 4.12 of this Policy not to have applied.

Section 6.3(b) is deleted in its entirety and replaced with the following:

Per Loan Loss Percentage Option. In the event the Company does not acquire the Property, allow the Insured to retain all rights and title to the Property and pay to the Insured as the Loss the lesser of: (i) the difference between the Claim Amount calculated in accordance with Section 6.2 and the amount realized by the Insured pursuant to its sale, if any, of the Property as provided in Section 5.10 and (ii) the Per Loan Loss Percentage option which shall be calculated by multiplying the applicable Per Loan Loss Percentage for such Loan times the Claim Amount (without any reduction for the Primary Policy claim payment pursuant to Section 6.2(vi)). However, if prior to the Company's payment of the Loss, a third party acquires title to the Property at the foreclosure sale or a Borrower redeems the Property (unless such acquisition or redemption occurs because the Insured failed to bid as provided in Section 5.11), then the Company shall pay the lesser of: (i) the Per Loan Loss Percentage option amount described above; or (ii) the difference between the Claim Amount and the amount realized by the Insured at the foreclosure sale or redemption; or

The following is added at the end of Section 6.3:

Without limiting the requirements and conditions to filing and payment of a Claim contained in this Policy, if the Property has been acquired by the insurer under a Primary Policy, no Loss shall be payable under this Policy. For purposes of this Policy any references to "percentage guaranty option" shall be to the "Per Loan Loss Percentage guaranty option".

II.

Other Provisions

Section 1.13 of the Policy is deleted in its entirety and replaced with the following:

1.13

Insured means:

The Person designated on the face of this Policy; or

Any Person to whom coverage has been assigned as permitted by Section 3.5 resulting in a change in the Insured named on a Certificate in accordance with this Policy.

Section 1.24 is amended by adding the following sentence at the end thereof:

"For purposes of this Policy, the term "Servicer" shall include the master servicer for a Loan of whom the Company has been notified, as well as any servicer acting on behalf of the master servicer of whom the Company has been notified."

Section 2.3 of the Policy is amended to read in its entirety as follows:

2.3

Company's Remedies for Misrepresentation -- Subject to Section 2.4, if any of the Insured's representations as described in Section 2.2 are materially false or misleading with respect to a Loan, the Company will have at its option, the right to defend against a Claim with respect to such Loan, or to the extent permitted by applicable law, to cancel or rescind coverage under any Certificate with respect to such Loan retroactively to commencement of coverage (or if the misrepresentation occurs with respect to continuation of coverage upon assumption of a Loan, to so defend, cancel or rescind retroactively to the date of such continuation with respect to such Loan). In the case of such cancellation or recission, the Company shall return at that time all paid premiums retroactively to such applicable date.

Section 2.4 and all references thereto in the Policy are deleted in their entirety.

Section 2.6a. of the Policy is amended to read in its entirety as follows:

The Company must give the Insured prior notice of the due date for payment of the applicable premium payable for coverage of all Loans insured under this Policy. The entire premium for all Loans must be paid within a forty-five (45) day grace period (or such longer grace period generally allowed by the Company) after the due date for payment, except that if a Default on a Loan occurs between the last date through which the applicable monthly renewal premium has been paid and the end of such grace period, the Insured shall not be required to pay monthly renewal premiums in connection with such Loan, and coverage of such Default will continue, while such Default exists. If such Default is not cured and results in a Claim, such unpaid monthly renewal premiums through the renewal month in which such Default occurred shall be paid as provided in Section 6.3 by deduction from the Loss.

Upon payment of the entire premium for all Loans within such grace period, this Policy will be in effect for the applicable period of coverage and a Default on a Loan occurring within said grace period which is not cured, and which results in a Claim being filed, will be covered.

If a Default occurs prior to the date through which the entire premium for all Loans has been paid, and if such Default is not cured and results in a Claim being filed, such Default shall remain covered and no further premium on such Loan in Default shall be due in order to maintain coverage of such Default. If such Default is cured, all monthly renewal premiums not paid during the period of Default shall be payable (unless previously paid by the Insured) within forty-five (45) days or such longer period generally allowed by the Company after notice from the Company in order to continue coverage.

If the entire premium for all Loans is not paid within the grace period, at the option of the Company, the coverage of this Policy and the Company's liability as to all Loans will terminate effective as of 12:01 a.m. on the first day following the date through which the applicable premium has been paid and as a result, any existing or future Defaults on any of the Loans will not be covered under this Policy.

Notwithstanding the foregoing, the Insured shall remain obligated to continue coverage in effect and pay any premium which is due, as required by Section 2.8 of this Policy.

Section 2.8 is amended to read in its entirety as follows:

2.8

Cancellation by the Insured of a Certificate --- Notwithstanding any provision to the contrary in this Policy, the Insured shall be obligated to maintain coverage of a Certificate for a Loan and to pay corresponding premiums for continuation of such coverage for each month or partial month coverage is in effect unless or until (a) the Loan is paid in full or (b) the ratio of the outstanding principal balance of the Loan to the Value (as defined in Section 1.26 of the Policy) of the Property securing the Loan is at least five (5 ) percentage points less than the Original LTV minus the percentage of coverage for such Loan under this Policy or (c) if otherwise permitted in writing by the Company. Subject to the foregoing obligation of the Insured to maintain coverage, the Insured may obtain cancellation of coverage on a Loan by making a written request to the Company for cancellation of coverage on the Loan. However, no refund will be paid upon cancellation of coverage on a Loan. Cancellation of coverage on a Loan will not cancel this Policy.

Section 3.5 is amended to read in its entirety as follows:

3.5

Change of Insured --- Change of Insured shall only be allowed if advance written approval is obtained from the Company (which approval shall be in the sole and absolute discretion of the Company). If coverage of a Loan is to be assigned or transferred by the Insured to a new Insured, the Insured shall request the Company's approval thereof and if the Company approves the change of Insured, the Company shall, thereafter, change its records to identify the new Insured for such Loan. Notwithstanding the foregoing, upon notice to the Company, the Insured may transfer coverage of a Loan to the Owner thereof or, upon the securitization of a Loan, to any trustee in such securitization, in each case without the prior approval of the Company; provided, however, that if in connection therewith there is a change in Servicer or if the servicing of the Loan is assumed by the new Insured or another Person, Section 3.4 of this Policy shall apply and the approval by the Company of such new Servicer, Insured or other Person shall be required.

All terms capitalized will have the meanings set forth in the Policy, except as otherwise defined herein. Nothing herein contained will be held to vary, alter, waive or extend any of the terms and conditions of the Policy, or any amendments thereto, except as expressly set forth above.

Structured Asset Investment Loan Trust 2004-BNC1 8-K