October 8, 1997

                                                        [EXHIBIT 99.10 TO S-4]








                                   October 8, 1997 



P.T.C. Bancorp
0000 Xxxxxxxx Xxxxxx
Xxxxxxxxxx, XX  00000

Indiana United Bancorp
000 X. Xxxxxxxx
Xxxxxxxxxx, XX  00000

Gentlemen:

     In my capacity as a shareholder of P.T.C. Bancorp ("PTC"), and not in my
capacity as a current director or officer of PTC, I hereby confirm my agreement
made with each of you to induce you to execute respectively the Agreement and
Plan of Merger (the "Agreement") dated as of October 8, 1997 between Indiana
United Bancorp ("IUB") and PTC.  Our agreement is as follows:

     1.   At any meeting of the shareholders of PTC: 

          (a)  I will vote all of my shares of PTC Common Stock ("Shares") in
               favor of the transactions contemplated by the Agreement;

          (b)  I will vote my Shares against any action or agreement that would
               result in a breach in any material respect of any covenant,
               representation or warranty or any other obligation of IUB under
               the Agreement; and

          (c)  I will vote my Shares against any action or agreement that would
               impede, interfere with or attempt to discourage the consummation
               of the transactions contemplated by the Agreement, including, but
               not limited to:

               (i)  any extraordinary corporate transaction (other than the
                    merger contemplated by the Agreement), such as a merger,
                    consolidation, business combination, share exchange,
                    reorganization, recapitalization or liquidation involving
                    PTC;



October 8, 1997
Page 2

               (ii) a sale or transfer of a material amount of assets of PTC;

               (iii)any change in the management or board of directors of PTC,
                    except as otherwise agreed to in writing by you; or

               (iv) any other material change in PTC's corporate structure or
                    business.

     2.   Until termination of the Agreement in accordance with its terms:

          (a)  I will maintain full voting power over all of the Shares over
               which I have such power at the date of this agreement; and

          (b)  I will not solicit or enter into any negotiations with, or
               furnish or cause to be furnished any information concerning the
               business or assets of PTC to, any person or entity (other than
               PTC or IUB in connection with the Agreement) and I will promptly
               communicate to you any solicitation or inquiry I receive.

     It is understood and acknowledged that nothing contained in our agreement
is intended to restrict me from voting on any matter, or otherwise from acting,
in my capacity as a director or officer of PTC with respect to any matter,
including but not limited to, the management or operation of PTC.

                                   Very truly yours,



                                     /s/  Xxxxx X. Xxxxx
                                    ----------------------------------