<PAGE>

                                                                    EXHIBIT 10.8

United Bancorp, Inc.
Director Supplemental Life Insurance Plan

                              UNITED BANCORP, INC.
                                AND SUBSIDIARIES
                    DIRECTOR SUPPLEMENTAL LIFE INSURANCE PLAN

                         EFFECTIVE _______________, 2003

<PAGE>

United Bancorp, Inc.
Director Supplemental Life Insurance Plan

                              UNITED BANCORP, INC.
                                AND SUBSIDIARIES
                    DIRECTOR SUPPLEMENTAL LIFE INSURANCE PLAN

         Pursuant to due authorization by its Board of Directors, the
undersigned, United Bancorp, Inc., an Ohio Corporation located in Martins Ferry,
Ohio (the "Company"), did constitute, establish and adopt the following Director
Supplemental Life Insurance Plan (the "Plan"), effective ________________, 2003.

         The purpose of this Plan is to attract, retain, and reward highly
qualified Directors, by dividing the death proceeds of certain life insurance
policies which are owned by the Company on the lives of the participating
Directors with the designated beneficiary of each insured participating
Director. The Company will pay the life insurance premiums from its general
assets.

                                    ARTICLE 1
                                   DEFINITIONS

         Whenever used in this Plan, the following terms shall have the meanings
specified:

1.1         "Beneficiary" means each designated person, or the estate of a
            deceased Participant, entitled to benefits, if any, upon the death
            of a Participant.

1.2         "Beneficiary Designation Form" means the form established from time
            to time by the Plan Administrator that a Participant completes,
            signs and returns to the Plan Administrator to designate one or more
            Beneficiaries.

1.3         "Board" means the Board of Directors of the Company as from time to
            time constituted.

1.4         "Change of Control" means a change in control of a nature that would
            be required to be reported in response to Item 5(f) of Schedule 14A
            of Regulation 14A promulgated under the Securities Exchange Act of
            1934, as amended (the "Exchange Act"), whether or not the Company is
            then subject to such reporting requirement; provided that, without
            limitation, such a change in control shall be deemed to have
            occurred if (A) any "person" (as such term is used in Sections 13(d)
            and 14(d) of the Exchange Act) is or becomes the "beneficial owner"
            (as defined in Rule 13d-3 under the Exchange Act), directly or
            indirectly, of securities of the Company representing 30% or more of
            the combined voting power of the Company's then outstanding
            securities; (B) during any period of two (2) consecutive years,
            individuals who at the beginning of such period constitute the
            Board, including for this purpose any new director whose election or
            nomination for election by the Company's stockholders was approved
            by a vote of at least two-thirds of the directors then still in
            office who were directors at the beginning of the period, cease for
            any reason to constitute a majority thereof; or (C) the business of
            the Company for which your services are principally performed is
            disposed of by the Company pursuant to a partial or complete
            liquidation of the Company, a sale of assets (including stock of a
            subsidiary) of

                                       1
<PAGE>

United Bancorp, Inc.
Director Supplemental Life Insurance Plan

         the Company, or otherwise.

1.5      "Company" means United Bancorp, Inc. and any of its subsidiaries (now
         in existence or hereafter formed or acquired) that have been selected
         by the Board to participate in the Plan and have adopted the Plan as a
         sponsor.

1.6      "Director" means an active director of the Board.

1.7      "Disability" means the Participant's suffering a sickness, accident or
         injury which has been determined by the Plan Administrator, in its sole
         and absolute discretion, to render the Participant disabled. Upon the
         request of the Plan Administrator, the Participant must submit to
         reasonable physical examination(s) by a physician chosen by the Plan
         Administrator.

1.8      "Company's Interest" means the benefit set forth in Section 3.2.

1.9      "Election to Participate" means the form required by the Plan
         Administrator of an eligible Director to indicate acceptance of
         participation in this Plan.

1.10     "Insured" means the individual Participant whose life is insured.

1.11     "Insurer" means the insurance company issuing the life insurance policy
         on the life of the Insured.

1.12     "Net Death Proceeds" means the total death proceeds of the Policy minus
         the cash surrender value.

1.13     "Normal Retirement Age" means the Participant attaining age 75.

1.14     "Normal Retirement Date" means the later of the Normal Retirement Age
         or the date of Termination of Service.

1.15     "Participant" means a Director (i) who is selected to participate in
         the Plan, (ii) who elects to participate in the Plan, (iii) who signs
         an Election to Participate and a Beneficiary Designation Form, (iv)
         whose signed Election to Participant and Beneficiary Designation Form
         are accepted by the Plan Administrator, (v) who commences participation
         in the Plan, and (vi) whose Participation has not terminated.

1.16     "Participant's Interest" means the benefit set forth in Section 3.1.

1.17     "Policy" means the individual insurance policy or policies adopted by
         the Plan Administrator for purposes of insuring a Participant's life
         under this Plan.

1.18     "Plan Administrator" means the plan administrator described in Article
         9.

                                       2
<PAGE>

United Bancorp, Inc.
Director Supplemental Life Insurance Plan

1.19     "Termination of Service" means the termination of Participant's
         service, for any reason, before Normal Retirement Age.

                                    ARTICLE 2
                                  PARTICIPATION

2.1      Selection by Plan Administrator. Participation in the Plan shall be
         limited to those Directors of the Company selected by the Plan
         Administrator, in its sole discretion, to participate in the Plan.

2.2      Enrollment Requirements. As a condition to participation, each selected
         Director shall complete, execute and return to the Plan Administrator
         (i) an Election to Participate, and (ii) a Beneficiary Designation
         Form. In addition, the Plan Administrator shall establish from time to
         time such other enrollment requirements as it determines in its sole
         discretion are necessary.

2.3      Eligibility; Commencement of Participation. Provided a Director
         selected to participate in the Plan has met all enrollment requirements
         set forth in this Plan and required by the Plan Administrator, that
         Director will become a Participant, be covered by the Plan and will be
         eligible to receive benefits at the time and in the manner provided
         hereunder, subject to the provisions of the Plan.

2.4      Termination of Participation. A Participant's rights under this Plan
         shall automatically cease and his or her participation in this Plan
         shall automatically terminate upon Termination of Service prior to
         Normal Retirement Age for reasons other than Disability or within
         twelve (12) months following a Change of Control. In the event that the
         Company decides to maintain the Policy after the Participant's
         termination of participation in the Plan, the Company shall be the
         direct beneficiary of the entire death proceeds of the Policy.

2.5      Disability.

         (a)      Except as otherwise provided in paragraph (b) of this Section
                  2.5, if the Participant's service on the Board is terminated
                  because of the Participant's Disability, the Company shall
                  maintain the Policy in full force and effect and, in no event,
                  shall the Company amend, terminate or otherwise abrogate the
                  Participant's Interest in the Policy. However, the Company may
                  replace the Policy with a comparable insurance policy to cover
                  the benefit provided under this Plan.

         (b)      Notwithstanding the provisions of paragraph (a) of this
                  Section 2.5, upon the disabled Participant's service on the
                  board of directors of any entity that the Plan Administrator,
                  in its sole and absolute discretion, determines to be in
                  competition with the Company, the Company shall have no
                  further obligation to the disabled Participant, and the
                  disabled Participant's rights pursuant to the Plan shall
                  cease.

                                       3
<PAGE>

United Bancorp, Inc.
Director Supplemental Life Insurance Plan

                  In the event the disabled Participant's rights are terminated
                  hereunder and the Company decides to maintain the Policy, the
                  Company shall be the direct beneficiary of the entire death
                  proceeds of the Policy.

2.6      Retirement. If the Participant remains in the continuous service on the
         Board, upon the Participant's Normal Retirement Date, the Company shall
         maintain the Policy in full force and effect and in no event shall the
         Company amend, terminate or otherwise abrogate the Participant's
         Interest in the Policy. However, the Company may replace the Policy
         with a comparable insurance policy to cover the benefit under this
         Plan.

2.7      Change of Control. If the Participant suffers Termination of Service
         within twelve (12) months following a Change of Control, the Company
         shall maintain the Policy in full force and effect and in no event
         shall the Company amend, terminate or otherwise abrogate the
         Participant's Interest in the Policy. However, the Company may replace
         the Policy with a comparable insurance policy to cover the benefit
         under this Plan.

                                    ARTICLE 3
                           POLICY OWNERSHIP/INTERESTS

3.1      Participant's Interest. The Participant, or the Participant's assignee,
         shall have the right to designate the Beneficiary of an amount of death
         proceeds equal to One Hundred Thousand Dollars ($100,000), not to
         exceed the Net Death Proceeds, subject to:

         (a)      Forfeiture of Participant's rights upon Termination of
                  Service;

         (b)      Termination of the Plan and the corresponding forfeiture of
                  rights for all Participants or any one Participant in
                  accordance with Section 9.1 hereof; and

         (c)      Forfeiture of the Participant's rights and interest hereunder
                  that the Company may reasonably consider necessary to conform
                  with applicable law (including the Sarbanes-Oxley Act of
                  2002).

3.2      Company's Interest. The Company shall own the Policy and shall have the
         right to exercise all incidents of ownership except that the Company
         shall not sell, surrender or transfer ownership of a Policy so long as
         a Participant has an interest in the Policy as described in Section
         3.1. This provision shall not impair the right of the Company, subject
         to Article 9, to terminate this Plan. With respect to each Policy, the
         Company shall be the beneficiary of the remaining death proceeds of the
         Policy after the Participant's Interest is determined according to
         Section 3.1.

                                    ARTICLE 4
                                    PREMIUMS

4.1      Premium Payment. The Company shall pay all premiums due on all
         Policies.

                                        4
<PAGE>

United Bancorp, Inc.
Director Supplemental Life Insurance Plan

4.2      Economic Benefit. The Plan Administrator shall determine the economic
         benefit attributable to any Participant based on the amount of the
         current term rate for the Participant's age multiplied by the aggregate
         death benefit payable to the Participant's Beneficiary. The "current
         term rate" is the minimum amount required to be imputed under Internal
         Revenue Notice 2002-8, or any subsequent applicable authority.

4.3      Imputed Income. The Company shall impute the economic benefit to the
         Participant on an annual basis, by adding the economic benefit to the
         Participant's W-2, or if applicable, Form 1099.

                                    ARTICLE 5
                                  BENEFICIARIES

5.1      Beneficiary. Each Participant shall have the right, at any time, to
         designate a Beneficiary(ies) to receive any benefits payable under the
         Plan to a beneficiary upon the death of a Participant. The Beneficiary
         designated under this Plan may be the same as or different from the
         Beneficiary designation under any other plan of the Company in which
         the Participant participates.

5.2      Beneficiary Designation; Change. A Participant shall designate a
         Beneficiary by completing and signing the Beneficiary Designation Form,
         and delivering it to the Plan Administrator or its designated agent.
         The Participant's beneficiary designation shall be deemed automatically
         revoked if the Beneficiary predeceases the Participant or if the
         Participant names a spouse as Beneficiary and the marriage is
         subsequently dissolved. A Participant shall have the right to change a
         Beneficiary by completing, signing and otherwise complying with the
         terms of the Beneficiary Designation Form and the Plan Administrator's
         rules and procedures, as in effect from time to time. Upon the
         acceptance by the Plan Administrator of a new Beneficiary Designation
         Form, all Beneficiary designations previously filed shall be cancelled.
         The Plan Administrator shall be entitled to rely on the last
         Beneficiary Designation Form filed by the Participant and accepted by
         the Plan Administrator prior to the Participant's death.

5.3      Acknowledgment. No designation or change in designation of a
         Beneficiary shall be effective until received, accepted and
         acknowledged in writing by the Plan Administrator or its designated
         agent.

5.4      No Beneficiary Designation. If the Participant dies without a valid
         designation of beneficiary, or if all designated Beneficiaries
         predecease the Participant, then the Participant's surviving spouse
         shall be the designated Beneficiary. If the Participant has no
         surviving spouse, the benefits shall be made payable to the personal
         representative of the Participant's estate.

5.5      Facility of Payment. If the Plan Administrator determines in its
         discretion that a benefit is to be paid to a minor, to a person
         declared incompetent, or to a person incapable of handling the
         disposition of that person's property, the Plan Administrator may
         direct

                                       5
<PAGE>

United Bancorp, Inc.
Director Supplemental Life Insurance Plan

         payment of such benefit to the guardian, legal representative or person
         having the care or custody of such minor, incompetent person or
         incapable person. The Plan Administrator may require proof of
         incompetence, minority or guardianship as it may deem appropriate prior
         to distribution of the benefit. Any payment of a benefit shall be a
         payment for the account of the Participant and the Participant's
         Beneficiary, as the case may be, and shall be a complete discharge of
         any liability under the Plan for such payment amount.

                                    ARTICLE 6
                                   ASSIGNMENT

         Any Participant may irrevocably assign without consideration all or
part of such Participant's Interest in this Plan to any person, entity or trust.
In the event a Participant shall transfer all or part of such Participant's
Interest, then all or part of that Participant's Interest in this Plan shall be
vested in his or her transferee, who shall be substituted as a party hereunder,
and that Participant shall have no further interest in this Plan.

                                    ARTICLE 7
                                     INSURER

         The Insurer shall be bound only by the terms of its given Policy. Any
payments the Insurer makes or actions it takes in accordance with a Policy shall
fully discharge it from all claims, suits and demands of all persons relating to
that Policy. The Insurer shall not be bound by or deemed to have notice of the
provisions of this Plan. The Insurer shall have the right to rely on the Plan
Administrator's representations with regard to any definitions, interpretations
or Policy interests as specified under this Plan.

                                    ARTICLE 8
                           CLAIMS AND REVIEW PROCEDURE

8.1      Claims Procedure. A Participant or Beneficiary ("claimant") who has not
         received benefits under the Plan that he or she believes should be paid
         shall make a claim for such benefits as follows:

         8.1.1    Initiation - Written Claim. The claimant initiates a claim by
                  submitting to the Plan Administrator a written claim for the
                  benefits.

         8.1.2    Timing of Plan Administrator Response. The Plan Administrator
                  shall respond to such claimant within 90 days after receiving
                  the claim. If the Plan Administrator determines that special
                  circumstances require additional time for processing the
                  claim, the Plan Administrator can extend the response period
                  by an additional 90 days by notifying the claimant in writing,
                  prior to the end of the initial 90-day period, that an
                  additional period is required. The notice of extension must
                  set forth the special circumstances and the date by which the
                  Plan Administrator expects to render its decision.

                                       6
<PAGE>

United Bancorp, Inc.
Director Supplemental Life Insurance Plan

         8.1.3    Notice of Decision. If the Plan Administrator denies part or
                  all of the claim, the Plan Administrator shall notify the
                  claimant in writing of such denial. The Plan Administrator
                  shall write the notification in a manner calculated to be
                  understood by the claimant. The notification shall set forth:

                  (a)      The specific reasons for the denial;

                  (b)      A reference to the specific provisions of the Plan on
                           which the denial is based;

                  (c)      A description of any additional information or
                           material necessary for the claimant to perfect the
                           claim and an explanation of why it is needed; and

                  (d)      An explanation of the Plan's review procedures and
                           the time limits applicable to such procedures.

8.2      Review Procedure. If the Plan Administrator denies part or all of the
         claim, the claimant shall have the opportunity for a full and fair
         review by the Plan Administrator of the denial, as follows:

         8.2.1    Initiation - Written Request. To initiate the review, the
                  claimant, within 60 days after receiving the Plan
                  Administrator's notice of denial, must file with the Plan
                  Administrator a written request for review.

         8.2.2    Additional Submissions - Information Access. The claimant
                  shall then have the opportunity to submit written comments,
                  documents, records and other information relating to the
                  claim. The Plan Administrator shall also provide the claimant,
                  upon request and free of charge, reasonable access to, and
                  copies of, all documents, records and other information
                  relevant to the claimant's claim for benefits.

         8.2.3    Considerations on Review. In considering the review, the Plan
                  Administrator shall take into account all materials and
                  information the claimant submits relating to the claim,
                  without regard to whether such information was submitted or
                  considered in the initial benefit determination.

         8.2.4    Timing of Plan Administrator's Response. The Plan
                  Administrator shall respond in writing to such claimant within
                  60 days after receiving the request for review. If the Plan
                  Administrator determines that special circumstances require
                  additional time for processing the claim, the Plan
                  Administrator can extend the response period by an additional
                  60 days by notifying the claimant in writing, prior to the end
                  of the initial 60-day period, that an additional period is
                  required. The notice of extension must set forth the special
                  circumstances and the date by which the Plan Administrator
                  expects to render its decision.

                                       7
<PAGE>

United Bancorp, Inc.
Director Supplemental Life Insurance Plan

         8.2.5    Notice of Decision. The Plan Administrator shall notify the
                  claimant in writing of its decision on review. The Plan
                  Administrator shall write the notification in a manner
                  calculated to be understood by the claimant. The notification
                  shall set forth:

                  (a)      The specific reasons for the denial;

                  (b)      A reference to the specific provisions of the Plan on
                           which the denial is based; and

                  (c)      A statement that the claimant is entitled to receive,
                           upon request and free of charge, reasonable access
                           to, and copies of, all documents, records and other
                           information relevant to the claimant's claim for
                           benefits.

                                    ARTICLE 9
                           AMENDMENTS AND TERMINATION

9.1      Amendment or Termination of Plan. Except as otherwise provided in
         Sections 2.5, 2.6, 2.7, and 9.2 or as otherwise agreed to in writing in
         an Addendum, the Company may amend or terminate this Plan for all
         Participants or for any Participant at any time prior to a
         Participant's death. Such amendment or termination shall be by written
         notice to the Participant(s). In the event that the Company decides to
         maintain the Policy after the Participant's termination of
         participation in the Plan, the Company shall be the direct beneficiary
         of the entire death proceeds of the Policy.

9.2      Amendment or Termination of Plan Upon Change of Control.
         Notwithstanding the provisions of Section 9.1, in the event of a Change
         of Control, the Company, or its successor, shall maintain in full force
         and effect each Policy that is in existence on the date the Change of
         Control occurs and shall not terminate or otherwise abrogate a
         Participant's Interest in the Policy. However, the Company may replace
         the Policy with a comparable insurance policy to cover the benefit
         provided under this Plan. This Section 9.2 shall apply to all
         Participants in the Plan on the date the Change of Control occurs,
         including but not limited to (i) a retired Participant who has an
         interest in the Plan pursuant to Section 2.6; (ii) a disabled
         Participant who has an interest in the Plan pursuant to Section 2.5;
         and (iii) a terminated Participant who has an interest in the Plan
         pursuant to Section 2.7.

9.3      Option to Purchase Upon Termination. If the Company exercises the right
         to terminate the Plan or a Participant's participation in the Plan, the
         Company shall not sell, surrender or transfer ownership of a Policy
         without first giving a Participant or the Participant's transferee the
         option to purchase the Policy for a period of sixty (60) days from
         written notice of such intention. The purchase price shall be an amount
         equal to the cash surrender value of the Policy.

9.4      Waiver of Participation. A Participant may, in the Participant's sole
         and absolute

                                       8
<PAGE>

United Bancorp, Inc.
Director Supplemental Life Insurance Plan

         discretion, waive his or her rights under the Plan at any time. Any
         waiver permitted under this Section 9.4 shall be in writing and
         delivered to the Plan Administrator.

                                   ARTICLE 10
                                 ADMINISTRATION

10.1     Plan Administrator Duties. This Plan shall be administered by a Plan
         Administrator which shall consist of the Board, or such committee as
         the Board shall appoint. Members of the Plan Administrator may be
         Participants under this Plan. The Plan Administrator shall also have
         the discretion and authority to (i) make, amend, interpret and enforce
         all appropriate rules and regulations for the administration of this
         Plan and (ii) decide or resolve any and all questions including
         interpretations of this Plan, as may arise in connection with the Plan.

10.2     Agents. In the administration of this Plan, the Plan Administrator may
         employ agents and delegate to them such administrative duties as it
         sees fit, (including acting through a duly appointed representative),
         and may from time to time consult with counsel who may be counsel to
         the Company.

10.3     Binding Effect of Decisions. The decision or action of the Plan
         Administrator with respect to any question arising out of or in
         connection with the administration, interpretation and application of
         the Plan and the rules and regulations promulgated hereunder shall be
         final and conclusive and binding upon all persons having any interest
         in the Plan.

10.4     Indemnity of Plan Administrator. The Company shall indemnify and hold
         harmless the members of the Plan Administrator against any and all
         claims, losses, damages, expenses or liabilities arising from any
         action or failure to act with respect to this Plan, except in the case
         of willful misconduct by the Plan Administrator or any of its members.

10.5     Information. To enable the Plan Administrator to perform its functions,
         the Company shall supply full and timely information to the Plan
         Administrator on all matters relating to the date and circumstances of
         the retirement, Disability, death or Termination of Service of its
         Participants, and such other pertinent information as the Plan
         Administrator may reasonably require.

                                   ARTICLE 11
                                  MISCELLANEOUS

11.1     Binding Effect. This Plan shall bind each Participant and the Company,
         their beneficiaries, survivors, executors, administrators and
         transferees and any Beneficiary.

11.2     No Guarantee Service. This Plan is not a contract. It does not give a
         Participant the right to remain a Director of the Company, nor does it
         interfere with the shareholders' right to terminate the service of a
         Participant. It also does not require a Participant to remain a

                                       9
<PAGE>

United Bancorp, Inc.
Director Supplemental Life Insurance Plan

         Director nor interfere with a Participant's right to terminate service
         at any time.

11.3     Applicable Law. The Plan and all rights hereunder shall be governed by
         and construed according to the laws of the State of Ohio, except to the
         extent preempted by the laws of the United States of America.

11.4     Reorganization. The Company shall not merge or consolidate into or with
         another company, or reorganize, or sell substantially all of its assets
         to another company, firm or person unless such succeeding or continuing
         company, firm or person agrees to assume and discharge the obligations
         of the Company under this Plan. Upon the occurrence of such event, the
         term "Company" as used in this Plan shall be deemed to refer to the
         successor or survivor company.

11.5     Notice. Any notice or filing required or permitted to be given to the
         Plan Administrator under this Plan shall be sufficient if in writing
         and hand-delivered, or sent by registered or certified mail, to the
         address below:

                                   United Bancorp, Inc

                                   Attention CEO

                                   201 S. 4th Street, P.O. Box 10

                                   Martins Ferry OH 43935

         Such notice shall be deemed given as of the date of delivery or, if
         delivery is made by mail, as of the date shown on the postmark or the
         receipt for registration or certification.

         Any notice or filing required or permitted to be given to a Participant
         under this Plan shall be sufficient if in writing and hand-delivered,
         or sent by mail, to the last known address of the Participant.

11.6     Entire Agreement. This Plan, along with a Participant's Election to
         Participate, Beneficiary Designation Form and any Addendum, constitute
         the entire agreement between the Company and the Participant as to the
         subject matter hereof. No rights are granted to the Participant under
         this Plan other than those specifically set forth herein.

      IN WITNESS WHEREOF, the Company executes this Plan as of the date
indicated above.

                                          United Bancorp, Inc.

                                          By ___________________________________

                                          Title ________________________________

                                       10
<PAGE>

                             ELECTION TO PARTICIPATE

         I, _____________________________, a Director designated as set forth in
Article 2 of the United Bancorp, Inc. Director Supplemental Life Insurance Plan
(the "Plan") dated ___________________________, hereby elect to become a
Participant of this Plan according to Article 2 of the Plan.

Additionally, I acknowledge that I have read the Plan document and agree to be
bound by its terms.

Executed this _____________ day of ____________________, 2003.

___________________________________
Participant

___________________________________
Plan Administrator

<PAGE>

United Bancorp, Inc.
Director Supplemental Life Insurance Plan

I designate the following as Beneficiary of benefits under this Plan payable
following my death.

Primary: _______________________________________________________________________

________________________________________________________________________________

Contingent:  __________________________________________________________________

________________________________________________________________________________

NOTE: TO NAME A TRUST AS BENEFICIARY, PLEASE PROVIDE THE NAME OF THE TRUSTEE(S)
      AND THE EXACT NAME AND DATE OF THE TRUST AGREEMENT.

I understand that I may change these designations of beneficiary by filing a new
written designation with the Plan Administrator. I further understand that the
designations will be automatically revoked if the Beneficiary predeceases me,
or, if I have named my spouse as beneficiary and our marriage is subsequently
dissolved.

PRINTED NAME: ______________________________

SIGNATURE:    ______________________________

DATE:         ______________________________

Acknowledged by the Plan Administrator this ________ day of ___________________,
20____

By ___________________________________

Title ________________________________

                                        1