X0306 4 2018-04-01 1 0000720002 MAINSOURCE FINANCIAL GROUP MSFG 0001214961 BROWN ARCHIE M JR 2105 N STATE RD 3 BYPASS GREENSBURG IN 47240 1 1 0 0 Chairman, President and CEO Common Stock 2018-04-01 4 D 0 56188 D 0 D Common Stock 2018-04-01 4 D 0 28081 D 0 I By 401-k Plan Stock Option (right to buy) 16.08 2018-04-01 4 D 0 10287 D 2024-02-03 Common Stock 10287 0 D On April 1, 2018, MainSource completed its previously announced merger (the "Merger")with First Financial Bancorp, pursuant to an Agreement and Plan of Merger, dated as of July 25, 2017, between MainSource and First Financial. In accordance with the terms of the Merger Agreement, at the effective time of the Merger each share of MainSource common stock issued an outstanding immediately prior to the Merger was converted into the right to receive 1.3875 shares of common stock of First Financial Bancorp. A cash payment of equal value was made in lieu of the issuance of fractional shares. This stock option was assumed by First Financial in the Merger and converted into an option to purchase from First Financial common shares on the same terms and conditions as were applicable under such MainSource option, a number of shares of First Financial common stock determined by multiplying (x) the number of shares of MainSource common stock subject to such MainSource common stock option immediately prior to the effective time by (y) the exchange ratio, at a per share exercise price equal to the quotient obtained by dividing (i) the per share exercise price for each share of MainSource common stock subject to such MainSource stock option by (ii) 1.3875. As authorized by power of attorney /s/ Denise Manus, attorney in fact 2018-04-03