UNITED STATES
                       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): April 25, 2006

                        MainSource Financial Group, Inc.
             (Exact name of registrant as specified in its charter)

          Indiana                        0-12422               35-1562245
  State or Other Jurisdiction       Commission File No.     I.R.S. Employer
  of Incorporation or Organization                         Identification Number


                               201 North Broadway
                            Greensburg, Indiana 47240
                    (Address of principal executive offices)

                                 (812) 663-0157
                         (Registrant's Telephone Number,
                              Including Area Code)

                                       N/A
          (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:

     [ ] 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 7.01.  Regulation FD Disclosure

On April 25, 2006,  MainSource Bank, the  wholly-owned  subsidiary of MainSource
Financial  Group,  Inc.,  issued a press release  announcing  the execution of a
definitive  agreement with First  Financial  Bank, N.A. for the purchase of five
branch  locations.  The press  release is attached  hereto as an exhibit to this
Current Report on Form 8-K and is being furnished  pursuant to this Item 7.01 as
Exhibit 99.1 to this Current Report on Form 8-K.

Item 9.01.        Financial Statements and Exhibits

     (c) The following exhibit is furnished with this report:

         Exhibit No.       Description

         99.1              MainSource Bank's press release dated April 25, 2006.



                                   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, thereunto duly authorized.


                                    MAINSOURCE FINANCIAL GROUP, INC.

Date:    April 25, 2006             By:  /s/ James L. Saner, Sr.
                                         -------------------------------------
                                         James L. Saner, Sr.
                                         President and Chief Executive Officer