EXHIBIT 99.1


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                                  NEWS RELEASE

        DATE:      April 25, 2006        9:15 a.m. E.S.T.
        CONTACT:   Daryl R. Tressler, Chairman and CEO
                   MainSource Bank - 812-663-4711

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                    MainSource Bank and First Financial Bank
                   Announce Purchase and Assumption Agreement


MainSource Financial Group, Inc., Greensburg,  Indiana (NASDAQ: MSFG) - Daryl R.
Tressler,  Chairman  and  Chief  Executive  Officer  of  MainSource  Bank  today
announced that MainSource Bank has executed a purchase and assumption  agreement
with First  Financial  Bank,  N.A. to purchase  five branch  locations  with one
office in each of Madison, East Enterprise and Liberty,  Indiana and two offices
in Vevay,  Indiana. In total, these branches comprise  approximately $30 million
in loans and $56 million in  deposits.  MainSource  Bank  currently  maintains a
presence in Jefferson and Switzerland Counties through three offices in Madison,
one office in Hanover, and one office in Vevay, Indiana.

The agreement calls for these offices to be merged into MainSource  Bank,  which
is a wholly owned  subsidiary of MainSource  Financial  Group.  The transaction,
which is expected to close in the third  quarter of 2006,  is subject to various
regulatory  approvals.  MainSource  Financial  Group  anticipates the deal to be
accretive to earnings within the first full year of consolidation.

Mr. Tressler stated, "This acquisition is a strategic opportunity for MainSource
Bank to expand our relationships in the Madison and Vevay markets.  In addition,
we are eager to expand  our  brand of  community  banking  to the  residents  of
Liberty and East  Enterprise,  Indiana.  This  acquisition will allow MainSource
Bank to be a stronger financial  institution that remains committed to community
values and local decision making."

The agreement  provides that the majority of consumer and small business deposit
accounts  and  loans,   including  checking,   savings,  home  equity,  CDs  and
installment  loans,  will be transferred to MainSource  Bank.  Consumers will be
notified in the coming  months with the  details of how their  accounts  will be
impacted.

MainSource Bank, Greensburg, Indiana, is a wholly-owned subsidiary of MainSource
Financial  Group,   Inc.,  a   community-focused,   financial   holding  company
headquartered in Greensburg,  Indiana.  MainSource  Financial Group is listed on
the  NASDAQ  National  Market  (under  the  symbol:   "MSFG"),   has  assets  of
approximately  $1.9 billion and  operates 60 offices in 27 Indiana  counties and
six offices in three Illinois  counties through its three banking  subsidiaries,
MainSource Bank,  Greensburg,  Indiana,  MainSource Bank of Illinois,  Kankakee,
Illinois, and MainSource Bank - Crawfordsville, Crawfordsville, Indiana. 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
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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 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 MainSource and its  subsidiaries'  loan and investment
portfolios; the timing of the closing of the transaction; the timing and success
of  integration   efforts  once  the   transaction  is  complete;   MainSource's
expectations  or ability to realize  success with the acquisition of branches of
First  Financial  Bank; and the impact of this  transaction,  if successful,  on
MainSource's business.

The forward-looking statements included in the press release relating to certain
matters  involve  risks  and  uncertainties,   including  anticipated  financial
performance,  business  prospects,  and other  similar  matters,  which  reflect
management's best judgment based on factors currently known.  Actual results and
experience  could  differ  materially  from  the  anticipated  results  or other
expectations expressed in MainSource's forward-looking statements as a result of
a number of factors,  including but not limited to, those discussed in the press
release.


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