EXHIBIT 99.1

Certification
of Principal Executive Officer Pursuant to 31 CFR Section 30.15

I,
Archie M. Brown, Jr., Chief Executive Officer, certify, based on my knowledge, that:

(i)  The
Executive Compensation Committee of MainSource Financial Group, Inc. has discussed, reviewed, and evaluated with senior risk officers at least every six
months during the period beginning on the later of September 14, 2009, or ninety days after the closing date of the agreement between MainSource Financial Group, Inc. and Treasury and
ending with the last day of MainSource Financial Group, Inc.'s fiscal year containing that date, the senior executive officer (SEO) compensation plans and the employee compensation plans and
the risks these plans pose to MainSource Financial Group, Inc.;

(ii)  The
Executive Compensation Committee of MainSource Financial Group, Inc. has identified and limited during the applicable period any features of the SEO
compensation plans that could lead SEOs to take unnecessary and excessive risks that could threaten the value of MainSource Financial Group, Inc. and during the same applicable period has
identified any features of the employee compensation plans that pose risks to MainSource Financial Group, Inc. and has limited those features to ensure that MainSource Financial
Group, Inc. is not unnecessarily exposed to risks;

(iii)  The
Executive Compensation Committee has reviewed, at least every six months during the applicable period, the terms of each employee compensation plan and identified
any features of the plan that could encourage the manipulation of reported earnings of MainSource Financial Group, Inc. to enhance the compensation of an employee, and has limited any such
features;

(iv)  The
Executive Compensation Committee of MainSource Financial Group, Inc. will certify to the reviews of the SEO compensation plans and employee compensation
plans required under (i) and (iii) above;

(v)  The
Executive Compensation Committee of MainSource Financial Group, Inc. will provide a narrative description of how it limited during any part of the most
recently completed fiscal year that included a TARP period the features in:



(vi)  MainSource
Financial Group, Inc. has required that bonus payments, as defined in the regulations and guidance established under section 111 of EESA (bonus
payments), of the SEOs and twenty next most highly compensated employees be subject to a recovery or "clawback" provision during any part of the most recently completed fiscal year that was a TARP
period if the bonus payments were based on materially inaccurate financial statements or any other materially inaccurate performance metric criteria;

(vii)  MainSource
Financial Group, Inc. has prohibited any golden parachute payment, as defined in the regulations and guidance established under section 111 of
EESA, to an SEO or any of the next five most highly compensated employees during the period beginning on the later of the closing date of the agreement between MainSource Financial Group, Inc.
and Treasury or June 15, 2009 and ending with the last day of MainSource Financial Group, Inc.'s fiscal year containing that date;

(viii)  MainSource
Financial Group, Inc. has limited bonus payments to its applicable employees in accordance with section 111 of EESA and the regulations and
guidance established thereunder during the period beginning on the later of the closing date of the agreement between MainSource Financial Group, Inc. and Treasury or June 15, 2009 and
ending with the last day of MainSource Financial Group, Inc.'s fiscal year containing that date;

(ix)  The
board of directors of MainSource Financial Group, Inc. has established an excessive or luxury expenditures policy, as defined in the regulations and guidance
established under section 111 of EESA, by the later of September 14, 2009, or ninety days after the closing date of the agreement between MainSource Financial Group, Inc. and
Treasury; this policy has been provided to Treasury and its primary regulatory agency; MainSource Financial Group, Inc. and its employees have complied with this policy during the applicable
period; and any expenses that, pursuant to this policy, required approval of the board of directors, a committee of the board of directors, an SEO, or an executive officer with a similar level of
responsibility, were properly approved;

(x)  MainSource
Financial Group, Inc. will permit a non-binding shareholder resolution in compliance with any applicable federal securities rules and regulations on
the disclosures provided under the federal securities laws related to SEO compensation paid or accrued during the period beginning on the later of the closing date of the agreement between MainSource
Financial Group, Inc. and Treasury or June 15, 2009 and ending with the last day of MainSource Financial Group, Inc. fiscal year containing that date;

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(xi)  MainSource
Financial Group, Inc. hereby discloses that it has not offered during the period beginning on the later of the closing date of the agreement between
MainSource Financial Group, Inc. and Treasury or June 15, 2009 and ending with the last day of MainSource Financial Group, Inc.'s fiscal year containing that date any perquisites,
as defined in the regulations and guidance established under section 111 of EESA, whose total value exceeds $25,000 for any employee who is subject to the bonus payment limitations identified
in paragraph (viii);

(xii)  No
compensation consultant has been engaged by MainSource Financial Group, Inc., the board of directors of MainSource Financial Group, Inc., or the
Executive Compensation Committee of MainSource Financial Group, Inc. during the period beginning on the later of the closing date of the agreement between MainSource Financial
Group, Inc. and Treasury or June 15, 2009 and ending with the last day of MainSource Financial Group, Inc.'s fiscal year containing that date;

(xiii)  MainSource
Financial Group, Inc. has prohibited the payment of any gross-ups, as defined in the regulations and guidance established under section 111
of EESA, to the SEOs and the next twenty most highly compensated employees during the period beginning on the later of the closing date of the agreement between MainSource Financial Group, Inc.
and Treasury or June 15, 2009 and ending with the last day of MainSource Financial Group, Inc.'s fiscal year containing that date;

(xiv)  MainSource
Financial Group, Inc. has substantially complied with all other requirements related to employee compensation that are provided in the agreement
between MainSource Financial Group, Inc. and Treasury, including any amendments;

(xv)  MainSource
Financial Group, Inc. has submitted to Treasury a complete and accurate list of the SEOs and the twenty next most highly compensated employees for the
current fiscal year and the most recently completed fiscal year, with the non-SEOs ranked in descending order of level of annual compensation, and with name, title, and employer of each SEO and most
highly compensated employee identified; and

(xvi)  I
understand that a knowing and willful false or fraudulent statement made in connection with this certification may be punished by fine, imprisonment, or both. (See,
for example, 18 U.S.C. 1001)

Date:
March 10, 2010

By:    /s/
ARCHIE M. BROWN, JR.
          Archie M. Brown, Jr., Chief Executive Officer

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