SEVERANCE AGREEMENT

Exhibit 10.4

SEVERANCE AGREEMENT

THIS SEVERANCE AGREEMENT (hereinafter referred to as this “Agreement”) is entered into as of the 8th day of November, 2007, by and between The National Bank and Trust Company, a national banking association (hereinafter referred to as “NB&T”), and Howard T. Witherby, Senior Vice President and Operations Division Manager of NB&T, an individual (hereinafter referred to as the “Employee”);

WITNESSETH:

WHEREAS, as a result of the skill, knowledge and experience of the Employee, the Board of Directors of NB&T desires to retain the services of the Employee as the Senior Vice President and Operations Division Manager of NB&T;

WHEREAS, the Employee desires to serve as the Senior Vice President and Operations Division Manager of NB&T; and

WHEREAS, the Employee and NB&T desire to enter into this Agreement to set forth their understanding as to their respective rights and obligations in the event of the termination of the Employee’s employment under the circumstances set forth in this Agreement.

NOW, THEREFORE, in consideration of the premises and mutual covenants herein contained, NB&T and the Employee hereby agree as follows:

1. Term. This Agreement shall commence on the date set forth above and shall end thirty-six (36) months thereafter, subject to earlier termination as provided herein (hereinafter referred to as the “Term”). The Term shall be extended automatically for one year on each anniversary of the date of this Agreement and shall continue to extend until NB&T elects not to extend the Term by providing notice to the Employee at least six months before the anniversary date.

2. Termination of Employment. For purposes of this agreement: (i) a termination of employment shall mean the Employee’s separation from service, as that phrase is defined in Section 409A of the Internal Revenue Code of 1986, as amended (“Code”) and Treasury Regulation (“Reg.”) § 1.409A-1(h); and (ii) any reference to a termination by or from NB&T shall include a termination by or from NB&T and any other entity that, along with NB&T, would be considered a “service recipient” within the meaning of Section 409A of the Code and Reg. § 1.409A-1(f).

(a) Termination for Just Cause.

(i) In the event that NB&T terminates the employment of the Employee before the expiration of the Term because of the Employee’s personal dishonesty; incompetence; willful misconduct; breach of fiduciary duty involving personal profit; intentional failure or refusal to perform the duties and responsibilities performed by the Employee at the time of execution of this Agreement or as otherwise consistent with the positions of Senior Vice President and Operations Division Manager of NB&T; willful violation of any law, rule, regulation (other than traffic violations or similar offenses) or final cease-and-desist order; conviction or plea of guilty or nolo contendere of a felony or for fraud or embezzlement; or material breach of any provision of this Agreement (hereinafter collectively referred to as “Just Cause”), the Employee shall not receive, and shall have no right to receive, any compensation or other benefits for any period after such termination.

(ii) For purposes of Section 2(a)(i):

(b) Termination without Just Cause and without a Change of Control. In the event that NB&T terminates the employment of the Employee before the expiration of the Term without Just Cause and on a date that is more than six months before the occurrence of a Change of Control (hereinafter defined) or that is more than one year following the occurrence of a Change of Control, the Employee shall not receive, and shall have no right to receive, any compensation or other benefits for any period after such termination.

(c) Termination in Connection with a Change of Control.

(i) In the event that NB&T terminates the employment of the Employee before the expiration of the Term without Just Cause and within six months before the occurrence of a Change of Control or within one year following the occurrence of a Change of Control, then the following shall occur:

(A) NB&T shall pay to the Employee, or to his dependents, beneficiaries or estate, an amount equal to two (2) times the Employee’s Compensation (as defined below) in a lump sum without reduction for time value of money or other discount. This payment shall be made as promptly as practicable, but in no event later than March 15 of the calendar year following the calendar year in which the termination occurred. For purposes of this section, the term “Employee’s Compensation” shall mean: (I) the higher of base salary immediately prior to the occurrence of the Change of Control or termination of the Employee’s employment; plus (II) the highest bonus paid to the Employee during the five (5) years preceding his termination;

(B) NB&T, its successors, survivors or assigns shall pay one hundred percent (100%) of all applicable premiums for continuation coverage for the Employee and his dependents under the group health plan of NB&T in which the Employee was a participant at any time during the period referred to in Section 2(c)(i) until the earlier of the expiration of the Term or the date on which the Employee is eligible to participate in a group health plan of another employer as a full-time employee; provided, however, that in no event shall this period extend beyond the period of time during which the Employee would be entitled to continuation coverage under the group health plan of NB&T under Section 4980B (COBRA) of the Code;

(C) NB&T, its successors, survivors or assigns shall reimburse the Employee for one hundred percent (100%) of all applicable premiums paid by the Employee and not otherwise reimbursed or compensated for by insurance for disability and life insurance policies not to exceed, in scope or benefit, any group disability and/or life insurance plan of NB&T in which the Employee was a participant at any time during the period referred to in Section 2(c)(i) until the earliest of the expiration of the Term, eighteen (18) months after the Employee’s termination of employment, or the date on which the Employee is eligible to participate in a similar disability or life insurance plan of another employer as a full-time employee. Any reimbursement made pursuant to this Section 2(c)(i)(C)) shall be made no later than the last day of the calendar year in which the Employee incurred the expense being reimbursed. In no event shall the amount of expenses eligible for reimbursement under this Section 2(i)(C) for any calendar year affect the expenses eligible for reimbursement in an other calendar year, and in no event may the Employee liquidate or exchange any right to reimbursement under this Section 2(i)(C) for any other right or benefit; and

(D) The Employee shall not be required to mitigate the amount of any payment provided for in this Agreement by seeking other employment or otherwise, nor shall any amounts received from other employment or otherwise by the Employee offset in any manner the obligations of NB&T hereunder, except as specifically stated in subsections (B) and (C).

(ii) The Employee may voluntarily terminate his employment with NB&T for Good Reason (as defined below) during the one-year period following the occurrence of a Change of Control and shall be entitled to the compensation and benefits as set forth in Section 2(c)(i) of this Agreement. For purposes of this subsection, the term “Good Reason” shall mean the occurrence of any of the following during the one-year period following the occurrence of a Change of Control:

(A) A material diminution in the Employee’s base compensation; or

(B) A material change in the geographic location at which the Employee is required to perform services (for this purpose and without limiting the foregoing, a material change is deemed to occur if the Employee is required to move his personal residence or perform his principal executive functions more than fifty (50) miles from his primary office as of the date of the commencement of the Term).

The Employee shall be required to provide written notice to NB&T or its successors, survivors or assigns within ninety (90) days of the initial existence of the condition constituting Good Reason and NB&T shall have thirty (30) days from the giving of this written notice in which to remedy the condition constituting Good Reason and not be required to pay the compensation and benefits described in Section 2(c)(i). If the Employee shall fail to provide such written notice to NB&T within the period described above, then he will be deemed to have consented to such condition and NB&T shall have no obligation to pay the compensation and benefits described in Section 2(c)(i) with respect to such condition.

(d) Death of the Employee. The Term shall automatically terminate upon the death of the Employee before his employment terminates. In the event of such death, the Employee’s estate shall be entitled to receive the compensation due the Employee through the last day of the calendar month in which the death occurred, except as otherwise specified herein, which compensation shall be paid no later than March 15 of the calendar year following the calendar year during which the Employee died.

(e) “Golden Parachute” Provisions.

(i) Any payments made to the Employee pursuant to this Agreement, or otherwise, are subject to and conditioned upon their compliance with 12 U.S.C. §1828(k) and regulations of the Office of the Comptroller of the Currency, the Federal Deposit Insurance Corporation and the Board of Governors of the Federal Reserve.

(ii) In the event that any payments pursuant to Section 2(c), alone or in combination with any other compensation, is subject to the excise tax described in Section 280G(b)(3) of the Code and the regulations promulgated thereunder (hereinafter collectively referred to as “Section 280G”), such payments shall be reduced to the maximum amount that may be paid under Section 280G without being considered an excess parachute payment subject to the excise tax imposed by Section 4999 of the Code. For purposes of this Section, any determination that a payment is subject to Section 280G and any determination of the maximum amount that may be paid under Section 280G shall be made in writing by the principal certified accounting firm or other professional selected by NB&T in its sole discretion. In the event a reduction in payments is necessary in order to comply with the requirements of this Agreement relating to the limitations of Section 280G or other applicable regulatory limits, the Employee may determine, in his sole discretion, the categories of current payments to be reduced or eliminated.

(f) Definition of “Change of Control”. A “Change of Control” shall mean any one of the following events: (i) the acquisition of ownership of, or power to vote, more than fifty (50) percent of the voting stock of NB&T or NB&T Financial Group, Inc., an Ohio corporation (hereinafter referred to as “NBTF”); (ii) the merger of NB&T or NBTF into, or the consolidation of NB&T or NBTF with, another corporation, or the merger of another corporation into NB&T or NBTF, on a basis whereby less than fifty (50) percent of the total voting power of the surviving corporation is represented by shares held by former shareholders of NBTF prior to such merger or consolidation; (iii) the acquisition of the ability to control the election of a majority of the directors of either of NB&T or NBTF; (iv) during any period of two consecutive years, individuals who at the beginning of such period constitute the Board of Directors of NB&T or NBTF cease for any reason to constitute at least a majority thereof; provided, however, that any individual whose election or nomination for election as a member of the Board of Directors of NB&T or NBTF was approved by a vote of at least two-thirds of the directors then in office shall be considered to have continued to be a member of the Board of Directors of NB&T or NBTF; (v) the acquisition by any person or entity of the power to direct NB&T’s management or policies, if the Board of Directors has made a determination that such acquisition constitutes or will constitute an acquisition of control of NB&T or NBTF for the purpose of the Bank Holding Company Act or the Change in Bank Control Act and the regulations thereunder; or (vi) NB&T shall have sold substantially all of its assets. For purposes of this paragraph, the term “person” refers to an individual, corporation, partnership, trust, association, joint venture, pool, syndicate or other organization or entity.

(g) Legal Fees. NB&T shall promptly pay all legal fees and expenses (including the costs of experts, evidence and counsel) that the Employee may incur as a result of the Employee or NB&T contesting the validity or enforceability of this Agreement or the Employee seeking to obtain or enforce any right or benefit provided by this Agreement if a court of competent jurisdiction renders a final decision in favor of the Employee with respect to any such contest, or to the extent agreed to by NB&T and the Employee in an agreement of settlement with respect to any such contest.

3. Consolidation, Merger or Sale of Assets. Nothing in this Agreement shall preclude NB&T from consolidating with, merging into, or transferring all, or substantially all, of its assets to another corporation that assumes all of NB&T’s obligations and undertakings hereunder. Upon such a consolidation, merger or transfer of assets, the term “NB&T” as used herein shall mean such other corporation or entity and this Agreement shall continue in full force and effect; provided, however, that the assumption of NB&T’s obligations and undertakings hereunder shall not affect the Employee’s right to payments pursuant to Section 2(c)(i) of this Agreement in connection with such consolidation, merger or transfer of assets.

4. Confidential Information. The Employee acknowledges that during his employment he will learn and have access to confidential information regarding NB&T and NBTF, and their customers and businesses. The Employee agrees and covenants not to disclose or use for his own benefit, or the benefit of any other person or entity, any confidential information, unless or until NB&T and NBTF consent to such disclosure or use. The Employee shall not knowingly disclose or reveal to any unauthorized person any confidential information relating to NB&T and NBTF, their parents, subsidiaries or affiliates, or to any of the businesses operated by them, and the Employee confirms that such information constitutes the exclusive property of NB&T and NBTF. The Employee shall not otherwise knowingly act or conduct himself (a) to the material detriment of NB&T and NBTF, their parents, subsidiaries or affiliates, or (b) in a manner which is inimical or contrary to the interests of NB&T and NBTF.

5. Nature of Employment. Nothing contained in this Agreement shall create any employment relationship between NB&T and NBTF other than an employment relationship that is terminable “at will.” NB&T may terminate the Employee’s employment at any time, subject to providing any payments specified herein in accordance with the terms hereof.

6. Nonassignability. Neither this Agreement nor any right or interest hereunder shall be assignable by the Employee, his beneficiaries or his legal representatives without NB&T’s prior written consent; provided, however, that nothing in this Section 6 shall preclude (a) the Employee from designating a beneficiary to receive any benefits payable hereunder upon his death, or (b) the executors, administrators, or other legal representatives of the Employee or his estate from assigning any rights hereunder to the person or persons entitled thereto.

7. No Attachment. Except as required by law, no right to receive payment under this Agreement shall be subject to anticipation, commutation, alienation, sale, assignment, encumbrance, charge, pledge or hypothecation or to execution, attachment, levy, or similar process of assignment by operation of law, and any attempt, voluntary or involuntary, to effect any such action shall be null, void and of no effect.

8. Amendment of Agreement. This Agreement may not be modified or amended, except by an instrument in writing signed by the parties hereto.

9. Waiver. No term or condition of this Agreement shall be deemed to have been waived, nor shall there be an estoppel against the enforcement of any provision of this Agreement, except by written instrument of the party charged with such waiver or estoppel. No such written waiver shall be deemed a continuing waiver, unless specifically stated therein, and each waiver shall operate only as to the specific term or condition waived and shall not constitute a waiver of such term or condition for the future or as to any act other than the act specifically waived.

10. Severability. If, for any reason, any provision of this Agreement is held invalid, such invalidity shall not affect the other provisions of this Agreement not held so invalid, and each such other provision shall, to the full extent consistent with applicable law, continue in full force and effect.

11. Headings. The headings of the paragraphs herein are included solely for convenience of reference and shall not control the meaning or interpretation of any of the provisions of this Agreement.

12. Governing Law; Regulatory Authority. This Agreement has been executed and delivered in the State of Ohio and its validity, interpretation, performance and enforcement shall be governed by the laws of the State of Ohio, except to the extent that federal law is governing.

13. Effect of Prior Agreements. This Agreement contains the entire understanding between the parties hereto and supersedes any other prior agreement between NB&T or any predecessor of NB&T and the Employee.

14. Notices. Any notice or other communication required or permitted pursuant to this Agreement shall be deemed delivered if such notice or communication is in writing and is delivered personally or by facsimile transmission or is deposited in the United States mail, postage prepaid, addressed as follows:

15. Compliance with Section 409A of the Code. The compensation and benefits payable pursuant to this Agreement are intended to be exempt from the requirements of Section 409A of the Code and, to the maximum extent permitted by law, shall be interpreted in a manner that results in its continued exemption from the requirements of that section. In the event it is determined that any compensation or benefit payable pursuant to this Agreement is deferred compensation and that the Employee is a “specified employee”, both within the meaning of Section 409A of the Code, then payments of such amount shall not be made until the earlier of six months following the date of the Employee’s termination or his death.

IN WITNESS WHEREOF, NB&T has caused this Agreement to be executed by its duly authorized officer, and the Employee has signed this Agreement, each as of the day and year first above written.