EXHIBIT 99.1


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                                  NEWS RELEASE

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     DATE:           December 27, 2005      11:30 a.m. E.S.T.
     CONTACT:        James L. Saner, Sr., President and CEO
                     MainSource Financial Group, Inc.   812-663-0157


                    MAINSOURCE FINANCIAL GROUP-NASDAQ, MSFG -
        Announces Restructuring of a Portion of Its Securities Portfolio


     MainSource  Financial  Group,  Inc.  (NASDAQ:  MSFG), the parent company of
MainSource Bank of Indiana and MainSource Bank of Illinois, announced today that
it  intends  to sell  approximately  $85  million  of  certain  under-performing
investment  securities.  The securities involved represent  approximately 18% of
the Company's securities portfolio and are currently yielding an average rate of
3.15%. As a result of this action, the Company expects to realize  approximately
$2.7 million in pre-tax  securities  losses in the fourth  quarter of 2005.  The
proceeds  generated  from  the  sale  will be used to  acquire  higher  yielding
investment  securities,  which is expected to improve the Company's net interest
margin and net interest  income in future periods.  MainSource  expects to fully
recover  these  losses in the next 18 to 24  months,  primarily  through  higher
tax-equivalent  income.  The restructuring  likely will have a minimal impact to
the Company's  shareholders'  equity as the decline in value of the  investments
currently is reflected in accumulated other comprehensive income.


     "These  securities  sales represent  important steps to better position the
Company for current and expected market  conditions,"  said James L. Saner, Sr.,
President and CEO of  MainSource.  "The  persistence  of low long-term  interest
rates and the  corresponding  flattening  of the yield  curve  continue to place
pressure on net interest margins industry-wide. In response to these challenging
conditions,  management  and the  Board of  Directors  have  decided  that it is
appropriate  to  reposition  our balance  sheet to enhance  our future  earnings
potential.  While this  action will  adversely  impact  earnings  for the fourth
quarter and year ended December 31, 2005, we expect it to help maintain  margins
prospectively.  Based upon our  current  interest  rate  forecasts,  longer-term
performance   should  be  enhanced  compared  with  holding  existing  portfolio
securities."

     MainSource Financial Group, Inc., headquartered in Greensburg,  Indiana, is
listed on the  NASDAQ  National  Market  (under  the  symbol:  "MSFG")  and is a
community-focused,  financial holding company with assets of approximately  $1.6
billion.  The Company operates 54 offices in 23 Indiana counties and six offices
in three  Illinois  counties  through its two banking  subsidiaries,  MainSource
Bank, Greensburg,  Indiana and MainSource Bank of Illinois,  Kankakee, Illinois.
Through its non-banking subsidiaries, MainSource Insurance LLC, MainSource Title
LLC,  and  MainSource  Mortgage  LLC,  the Company and its banking  subsidiaries
provide various related financial services.

Forward-Looking Statements

     Except for historical  information contained herein, the discussion in this
press  release  may  include  certain  forward-looking   statements  based  upon
management  expectations.  Factors  which could cause  future  results to differ
materially  from these  expectations  include the  following:  general  economic
conditions; legislative and regulatory initiatives; monetary and fiscal policies
of the federal  government;  deposit flows;  the costs of funds;  general market
rates of  interest;  interest  rates on competing  investments;  demand for loan
products;  demand for  financial  services;  changes in  accounting  policies or
guidelines;  and changes in the quality or composition of the Company's loan and
investment portfolios.