<PAGE>

                                                                    EXHIBIT 10.4

                        AMENDMENT TO EMPLOYMENT AGREEMENT

         This Amendment to Employment Agreement is entered between Mark W.
Immelt and First Financial Bancorp, effective as of the date of signing by the
undersigned executive, under the following circumstances:

         E.       Certain changes in the FFBC Split Dollar Life Insurance
                  Program and interest rates make it desirable for parties to
                  amend and clarify paragraph 5(h) of the employment agreement
                  in letter form, entered between the parties on or about August
                  4, 2000 (hereinafter "Employment Agreement").

         F.       The parties desire to reduce their agreement to amend their
                  Employment Agreement to writing.

         NOW, THEREFORE, the parties agree to the following amendment in
consideration of continued employment and other valuable consideration:

         5.       Section 5(h) of the Employment Agreement is amended as
                  follows:

                  (j)      If your Date of Termination is within twelve (12)
                           months after a Change in Control, and provided that
                           you either elect to have that Policy described in
                           your Split Dollar Agreement assigned to you as
                           specified in Section IX of the Split Dollar Agreement
                           or you consent to the termination of your rights
                           under the Split Dollar Agreement, you will receive a
                           payment (the "Split Dollar Payment") within ninety
                           (90) days of your Date of Termination in one lump-sum
                           equal to the present value of the death benefit you
                           would have received under the Split Dollar Agreement,
                           determined as if your last day of work was your Date
                           of Termination, were then eligible to receive a
                           retirement benefit under the early, normal, late, or
                           disability retirement provisions of First Financial
                           Bancorp Employees' Pension Plan (whether or not this
                           is actually the case), and died at age 75 when the
                           Split Dollar Agreement was still in effect. For
                           purposes of this Section 5, present value will be
                           determined using a discount rate based upon the
                           effective U.S. Treasury securities rate for the
                           applicable discount period (the number reached by
                           subtracting your age at Date of Termination from 75),
                           not to exceed 10 years. Notwithstanding the prior two
                           sentences, if you elect to receive an assignment of
                           the policy under Section IX of the Split Dollar
                           Agreement, the Split Dollar Payment shall be applied
                           to the cash payment to FFBC required under Section IX
                           of the Split Dollar Agreement, and any portion of the
                           Split Dollar Payment in excess of the amount required
                           under Section IX shall be paid to you. The provisions
                           of this Paragraph (h) will apply whether or not your
                           Split

<PAGE>

                           Dollar Agreement is terminated before you receive the
                           Split Dollar Payment.

                  6.       All of the terms of the Employment Agreement will
                           remain in effect.

FIRST FINANCIAL BANCORP:

By: /s/ Brian D. Moriarty           5/9/03
   ---------------------------------------
         Name                       Date

   Senior Vice President
------------------------------------------
         Title

EXECUTIVE:

/s/ Mark W. Immelt                 5/20/03
------------------------------------------
Mark W. Immelt                     Date