Exhibit 99.7a

Execution Version

ASSIGNMENT, ASSUMPTION AND RECOGNITION AGREEMENT

THIS ASSIGNMENT, ASSUMPTION AND RECOGNITION AGREEMENT (this “Assignment”), dated as of June 1, 2007 with an effective date of June 29, 2007 (the “Effective Date”), is entered into among Morgan Stanley Capital I Inc., a Delaware corporation (the “Depositor”), Morgan Stanley Mortgage Capital Holdings LLC, successor by merger to Morgan Stanley Mortgage Capital Inc. (“MSMCH”), Wachovia Mortgage Corporation as seller (“Wachovia,” or the “Seller”), and acknowledged by LaSalle Bank National Association, as trustee (the “Trustee”) of Morgan Stanley Mortgage Loan Trust 2007-11AR (the “Trust”).

RECITALS

WHEREAS Morgan Stanley Mortgage Capital Inc. and the Seller have entered into a certain Seller’s Purchase, Warranties and  Interim Servicing Agreement, dated as of February 28, 2005 and a certain First Amended and Restated Seller’s Purchase, Warranties and  Interim Servicing Agreement, dated as of June 1, 2006 (together, as amended or modified to the date hereof, the “Agreement”), pursuant to which MSMCH has acquired certain Mortgage Loans pursuant to the terms of the Agreement;

WHEREAS the Depositor has agreed, on the terms and conditions contained herein, to purchase from MSMCH certain of the Mortgage Loans (the “Specified Mortgage Loans”) which are subject to the provisions of the Agreement and are listed on the mortgage loan schedule attached as Exhibit I hereto (the “Specified Mortgage Loan Schedule”); and

WHEREAS the Trustee, on behalf of the Trust, has agreed, on the terms and conditions contained herein, to purchase from the Depositor the Specified Mortgage Loans;

NOW, THEREFORE, in consideration of the mutual promises contained herein and other good and valuable consideration (the receipt and sufficiency of which are hereby acknowledged), the parties agree as follows:

1.   Assignment and Assumption

(a)On and as of the date hereof, MSMCH hereby sells, assigns and transfers to the Depositor all of its right, title and interest in the Specified Mortgage Loans and all rights and obligations related thereto as provided under the Agreement to the extent relating to the Specified Mortgage Loans, the Depositor hereby accepts such assignment from MSMCH (the “First Assignment and Assumption”), and the Seller hereby acknowledges the First Assignment and Assumption.

MSMCH specifically reserves and does not assign to the Depositor hereunder any and all right, title and interest in, to and under and all obligations of MSMCH with respect to any Mortgage Loans subject to the Agreement which are not the Specified Mortgage Loans.

(b)On and as of the date hereof, immediately after giving effect to the First Assignment and Assumption, the Depositor hereby sells, assigns and transfers to the Trustee, on behalf of the Trust, all of its right, title and interest in the Specified Mortgage Loans and all rights and obligations related thereto as provided under the Agreement to the extent relating to the Specified Mortgage Loans, and the Trustee, on behalf of the Trust, hereby accepts such assignment from the Depositor (the “Second Assignment and Assumption”), and the Seller hereby acknowledges the Second Assignment and Assumption.

(c)On and as of the date hereof, MSMCH represents and warrants to the Depositor and the Trustee that MSMCH has not taken any action that would serve to impair or encumber the respective ownership interests of the Depositor and the Trustee in the Specified Mortgage Loans since the date of MSMCH’s acquisition of the Specified Mortgage Loans.

2.   Recognition of Trustee

(a)From and after the date hereof, both MSMCH and the Seller shall note the transfer of the Specified Mortgage Loans to the Trustee, in their respective books and records and shall recognize the Trustee, on behalf of the Trust, as of the date hereof, as the owner of the Specified Mortgage Loans. It is the intention of the Seller, the Servicer, the Depositor, the Trustee and MSMCH that this Assignment shall be binding upon and inure to the benefit of the Depositor, the Trustee and MSMCH and their respective successors and assigns.

(b)Without in any way limiting the foregoing, the parties confirm that this Assignment includes the rights relating to amendments or waivers under the Agreement.  Accordingly, the right of MSMCH to consent to any amendment of the Agreement and its rights concerning waivers as set forth in Sections 11.02 and 8.02 of the Agreement shall be exercisable, to the extent any such amendment or waiver affects the Specified Mortgage Loans or any of the rights under the Agreement with respect thereto (other than the servicing of the Specified Mortgage Loans, which shall be enforced by the Master Servicer) by the Trustee as assignee of MSMCH.

(c)It is expressly understood and agreed by the parties hereto that (i) this Assignment is executed and delivered by LaSalle Bank National Association, not individually or personally but solely on behalf of the Trust, as the assignee, in the exercise of the powers and authority conferred and vested in it, as Trustee, pursuant to the Pooling and Servicing Agreement dated as of the date hereof among the Depositor, Wells Fargo Bank, National Association, as securities administrator (the “Securities Administrator”) and as master servicer (the “Master Servicer”), and the Trustee (the “Pooling and Servicing Agreement”), (ii) each of the representations, undertakings and agreements herein made on the part of assignee is made and intended not as personal representations, undertakings and agreements by LaSalle Bank National Association but is made and intended for the purpose of binding only the Trust, (iii) nothing herein contained shall be construed as creating any liability for LaSalle Bank National Association, individually or personally, to perform any covenant (either express or implied) contained herein, (iv) under no circumstances shall LaSalle Bank National Association be personally liable for the payment of any indebtedness or expenses of the Trust, or be liable for the breach or failure of any obligation, representation, warranty or covenant made or undertaken by the Trust under this Assignment and (v) all recourse for any payment liability or other obligation of the assignee shall be had solely to the assets of the Trust.

3.   Representations and Warranties

(a)The Depositor represents and warrants that it is a sophisticated investor able to evaluate the risks and merits of the transactions contemplated hereby, and that it has not relied in connection therewith upon any statements or representations of the Seller or MSMCH other than those contained in the Agreement or this Assignment.

(b)Each of the parties hereto represents and warrants as of the Effective Date that it is duly and legally authorized to enter into this Assignment.

(c)Each of the Depositor, MSMCH, and Seller hereto represents and warrants as of the Effective Date that this Assignment has been duly authorized, executed and delivered by it and (assuming

2

due authorization, execution and delivery thereof by each of the other parties hereto) constitutes its legal, valid and binding obligation, enforceable against it in accordance with its terms, except as such enforcement may be limited by bankruptcy, insolvency, reorganization or other similar laws affecting the enforcement of creditors’ rights generally and by general equitable principles (regardless of whether such enforcement is considered in a proceeding in equity or at law).

(d)The Seller hereby makes, as of the Closing Date (as defined in the Pooling and Servicing Agreement referred to below), the representations and warranties set forth in Section 3.01 of the Agreement, to and for the benefit of the Depositor, the Trustee and the Trust, and by this reference incorporates such representations and warranties herein, as of such Closing Date.  The Seller hereby restates as of the closing date (as defined in the Agreement) the representations and warranties set forth in Section 3.02 of the Agreement to and for the benefit of the Depositor, the Trustee and the Trust, and by this reference incorporates such representations and warranties as of such date.

4.   Continuing Effect

Except as contemplated hereby, the Agreement shall remain in full force and effect in accordance with its terms.

5.   Governing Law

This Assignment and the rights and obligations hereunder shall be governed by and construed in accordance with the internal laws of the State of New York.

6.   Notices

Any notices or other communications permitted or required under the Agreement to be made to the Depositor, MSMCH, the Seller, and the Trustee shall be made in accordance with the terms of the Agreement and shall be sent as follows:

In the case of MSMCH:

Morgan Stanley Mortgage Capital Holdings LLC

1221 Avenue of the Americas

New York, New York 10020

Attention: Morgan Stanley Mortgage Loan Trust 2007-11AR

With a copy to:

Morgan Stanley & Co. Incorporated

1585 Broadway

New York, New York 10036

Attention: General Counsel’s Office

In the case of the Depositor:

Morgan Stanley Capital I Inc.

1585 Broadway

New York, New York 10036

Attention:  Morgan Stanley Mortgage Loan Trust 2007-11AR

3

In the case of the Trustee:

LaSalle Bank National Association

135 South LaSalle Street, Suite 1511

Chicago, Illinois 60603

Attention: Global Securities and Trust Services MSM 2007-11AR

In the case of Wachovia:

Wachovia Mortgage Corporation

901 South Tryon Street

Charlotte, North Carolina  28202

Attention:  Kendal Leeson

With a copy to:

Wachovia Mortgage Corporation

1100 Corporate Center Drive

Raleigh, North Carolina  27607

Attention:  Tom Fowler

or to such other address as may hereafter be furnished by the Depositor and the Trustee to the parties in accordance with the provisions of the Agreement.

7.   Ratification

Except as modified and expressly amended by this Assignment, the Agreement is in all respects ratified and confirmed, and all terms, provisions and conditions thereof shall be and remain in full force and effect.

8.   Counterparts

This Assignment may be executed in counterparts, each of which when so executed shall be deemed to be an original and all of which when taken together shall constitute one and the same instrument.

9.   Definitions

Any capitalized term used but not defined in this Assignment has the same meaning as in the Agreement.

[SIGNATURE PAGE FOLLOWS]

4

IN WITNESS WHEREOF, the parties hereto have executed this Assignment the day and year first above written.

MORGAN STANLEY MORTGAGE CAPITAL HOLDINGS LLC,

successor by merger to Morgan Stanley Mortgage Capital Inc.

By:  /s/ Valerie Kay                                                                              

Name:  Valerie Kay

Title:     Vice President

MORGAN STANLEY CAPITAL I INC.

By:  /s/ Valerie Kay                                                                              

Name:  Valerie Kay

Title:     Vice President

WACHOVIA  MORTGAGE CORPORATION

By:  /s/ Kendal A. Leeson                                                                              

Name:  Kendal A. Leeson

Title:    Vice President

Acknowledged and Agreed:

LASALLE BANK NATIONAL ASSOCIATION

as Trustee of Morgan Stanley Mortgage Loan Trust 2007-11AR

By: /s/ Andy Streepy                                            

Name:  Andy Streepy

Title:    Assistant Vice President

EXHIBIT I

Mortgage Loan Schedule

[see Schedule A to Pooling and Servicing Agreement]