SECURITIES AND EXCHANGE COMMISSION
                             WASHINGTON, D.C. 20549

                                    FORM 8-K

                                 CURRENT REPORT

                       PURSUANT TO SECTION 13 OR 15(D) OF
                       THE SECURITIES EXCHANGE ACT OF 1934

       Date of Report (Date of earliest event reported): December 8, 2009

                        MERIDIAN INTERSTATE BANCORP, INC.
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               (Exact Name of Registrant as Specified in Charter)

        Massachusetts                  001-33898                20-4652200
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(State or Other Jurisdiction     (Commission File No.)     (I.R.S. Employer
 of Incorporation)                                          Identification No.)


10 Meridian Street, East Boston, Massachusetts                    02128
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(Address of Principal Executive Offices)                        (Zip Code)

Registrant's telephone number, including area code:  (617) 567-1500
                                                     --------------


                                 Not Applicable
          -------------------------------------------------------------
          (Former name or former address, if changed since last report)

Check the appropriate box below if the Form 8-K filing is intended to
simultaneously satisfy the filing obligation of the registrant under any of the
following provisions (see General Instruction A.2. below):

[  ]  Written communications pursuant to Rule 425 under the Securities Act
      (17 CFR 230.425)

[  ]  Soliciting material pursuant to Rule 14a-12 under the Exchange Act
      (17 CFR 240.14a-12)

[  ]  Pre-commencement communications pursuant to Rule 14d-2(b) under the
      Exchange Act (17 CFR 240.14d-2(b))

[  ]  Pre-commencement communications pursuant to Rule 13e-4(c) under the
      Exchange Act (17 CFR 240.13e-4(c))





Item 1.01.     Entry into a Material Definitive Agreement

     On December 8, 2009, Meridian Interstate Bancorp, Inc., the parent company
of East Boston Savings Bank, entered into an amendment to the Agreement and Plan
of Merger (the "Merger Agreement") with Mt. Washington Cooperative Bank ("Mt.
Washington"). Pursuant to the Merger Agreement, Mt. Washington will merge with
and into East Boston Savings Bank. As a result of the amendment, the deadline
for completing the merger has been extended until January 8, 2010.

     The foregoing summary of the amendment to the Merger Agreement is not
complete and is qualified in its entirety by reference to the complete text of
such document, which is filed as Exhibit 2 to this Form 8-K and which is
incorporated herein by reference in its entirety.

Item 9.01.     Financial Statements and Exhibits

     (a) Financial Statements of Businesses Acquired. Not applicable.
     (b) Pro Forma Financial Information. Not applicable.
     (c) Shell Company Transactions. Not applicable.
     (d) Exhibits.

               Exhibit 2      Amendment No. 1 to Agreement and Plan of Merger,
                              dated as of December 8, 2009, by and among
                              Meridian Financial Services, Incorporated,
                              Meridian Interstate Bancorp, Inc., East Boston
                              Savings Bank and Mt. Washington Cooperative Bank





                                   SIGNATURES

     Pursuant to the requirements of the Securities Exchange Act of 1934, the
Registrant has duly caused this report to be signed on its behalf by the
undersigned, hereunto duly authorized.

                                        MERIDIAN INTERSTATE BANCORP, INC.



DATE: December 10, 2009             By: /s/ Richard J. Gavegnano
                                        ---------------------------------------
                                        Richard J. Gavegnano
                                        Chairman and Chief Executive Officer