**Wilshire
                  Credit Corporation****Payments**P.O.
                  Box 30040; Los Angeles, CA 90030-0040or
                  P.O. Box 650314; Dallas, TX 75265-0314Exhibit
                  T
              **Correspondence**P.O.
                  Box 8517; Portland, OR 97207-8517SARBANES-OXLEY
                    CERTIFICATION
              **Phone**(503)
                  952-7947(888)
                  502-0100**Fax**(503)
                  952-7476March
                  1, 2007
              **Web
                  Site**www.wfsg.com


Merrill
      Lynch Mortgage Investors, Inc.


250
      Vesey
      Street


4
      World
      Financial Center, 10th Floor


New
      York,
      New York 10080




LaSalle
      Bank National Association


135
      South
      LaSalle Street


Chicago,
      Illinois 60603


Attn:      
      Jennifer Wilt, Corporate Trust Services—Merrill Lynch Mortgage


Investors
      Trust, Series
      2006-SD1




Re: Merrill
      Lynch Mortgage Investors Trust, Mortgage Loan Asset-Backed Certificates, Series
      2006-SD1, Pool 674




I,
      Ken Frye, Senior Vice President,
      Loan Servicing, certify that:




1.  I
      have reviewed the report on Form 10-K and all reports on Form 10-D required
      to
      be filed in respect of the period covered by this report on Form 10-K of Merrill
      Lynch Mortgage Investors, Inc., Depositor (the “Exchange Act periodic
      reports”);




2.  Based
      on my knowledge, the Exchange Act periodic reports, taken as a whole, do not
      contain any untrue statement of a material fact or omit to state a material
      fact
      necessary to make the statements made, in light of the circumstances under
      which
      such statements were made, not misleading with respect to the period covered
      by
      this report;




3.  Based
      on my knowledge, all of the distribution, servicing and other information
      required to be provided under Form 10-D for the period covered by this report
      is
      included in the Exchange Act periodic reports;




4.  I
      am responsible for reviewing the activities performed by the Servicer and based
      on my knowledge and the compliance review conducted in preparing the Servicer
      compliance statement required by this report under Item 1123 of Regulation
      AB,
      and except as disclosed in the Exchange Act periodic reports, the Servicer
      has
      fulfilled its obligations under the Servicing Agreement; and




5.  All
      of the reports on assessment of compliance with servicing criteria for ABS
      and
      their related attestation reports on assessment of compliance with servicing
      criteria for asset-backed securities required to be included in this report
      in
      accordance with Item 1122 of Regulation AB and Exchange Act Rules 13a-18 and
      15d-18 have been included as an exhibit to this report, except as otherwise
      disclosed in this report. Any material instances of noncompliance described
      in
      such reports have been disclosed in this report on Form 10-K.




In
      giving the certifications above, I
      have reasonably relied on information provided to me by the Trustee, LaSalle
      Bank National Association, an unaffiliated party.




Wilshire
      Credit Corporation,


as
      Servicer




By:
/s/
      Ken Frye


Name:
      Ken
      Frye


Title:
      Senior Vice President Loan Servicing


(Senior
      Officer in charge of the servicing function of the servicer