Document:

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                                                                     Exhibit 10A

                                    Viad Corp
                            1850 North Central Avenue
                                Phoenix, AZ 85077
                                  602-207-4000

                                                                   March 1, 2000

Mr. Paul B. Mullen
2332 Timberline Way
Las Vegas, Nevada 89117

Dear Paul:

      The provisions of this letter shall be effective as of March 1, 2000
("Commencement Date"), and shall constitute an "Agreement" governing your
employment with GES Exposition Services, Inc. ("GES"), a wholly-owned subsidiary
of Viad Corp ("Employer"). Effective upon the Commencement Date, the term of the
letter agreement dated as of April 25, 1996, between Employer and you shall be
deemed to have expired. In consideration of your entering into this Agreement,
you release and discharge Employer and GES from all claims in connection with
the prior agreement.

      1. Employment. You shall be employed as Chairman of GES during the term of
this Agreement. Unless you first obtain the written consent of the Employer, you
will devote your best efforts, energies, skills and all of your working time to
the discharge of the duties and responsibilities as may from time-to-time be
prescribed by GES' President and Chief Executive Officer and/or Employer's
Chairman or Board of Directors (including, but not limited to, developing new
business, helping retain existing customers and partnering customers); to serve
the best interest of Employer and GES; to perform your tasks to the reasonable
satisfaction of GES; and to be responsible to GES' President and Chief Executive
Officer and/or Employer's Chairman for the performance of the business of GES
and its subsidiaries. You understand that your duties may require you to travel
outside of the State of Nevada from time to time. However, you shall have as
your principal office the offices of the Employer in Las Vegas, Nevada
throughout the term of this Agreement and the Employer may not assign you for a
period to exceed thirty (30) days to a geographic location outside Clark County
without your permission. Written consent of the Employer shall not be required
as to your reasonable participation in educational, consultative, and
professional society activities related to the maintenance of your
qualifications and stature in your professional community.

      2.    Term.

      (a)   The initial term of your employment shall commence on the
            Commencement Date and continue for a period of one (1) year
            thereafter, and shall be automatically renewed for successive one
            year terms, subject to termination as provided below.
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Mr. Paul B. Mullen
March 1, 2000
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      (b)   Employer and you may terminate your employment under this Agreement
            at any time, with or without cause, upon thirty (30) days' prior
            written notice to the other party at any time after three (3) months
            after the Commencement Date.

      3. Compensation. You will be provided a base compensation of $322,905 per
year (prorated for partial years during the term of employment). This base
compensation will remain fixed for a period of time until Employer determines
when market conditions would indicate merit increases, based upon your
performance, should commence. You will be entitled to participate in incentive
compensation plans of Employer which shall include Employer's Management
Incentive Plan ("MIP") with a target eligibility of 45% of base compensation,
and, subject to Employer's Board approval, will be eligible to participate in
Employer's Stock Option Program, Performance Unit Incentive Plan, and
Performance-Based Stock Plan.

      4. Other Benefits. You shall be entitled to all fringe benefits or
perquisites provided by Employer or GES to its executives, generally using,
whenever applicable, base compensation as the basis for determining such
benefit. The benefits shall include, inter alia, participation in the Employer's
Executive Severance Plan, executive health, dental, life and disability plans,
and the GES 401K Plan and the GES Supplemental Employees Retirement Plan.

      In addition, in your case, such benefits or perquisites shall also include
the use of a luxury automobile, financial counseling, a country club's monthly
dues (excluding initiation fees), and a luncheon and health club dues. You are
also authorized to obtain first class air travel on Employer or GES business.

      5. Noncompete. In exchange for the additional consideration given pursuant
to paragraph 6 below, upon termination of your employment (by either you or
Employer), you will not, either for yourself or for another, or as an employee,
independent contractor, partner, consultant, affiliate or controlling
stockholder of any person or entity, (Nothing contained herein shall prevent you
from purchasing stock or issue of debt securities in any corporation listed on
any stock exchange or traded in the over-the-counter market provided that such
purchases shall not result in your ownership, in the aggregate, directly or
indirectly, five percent [5%] or more of the securities of any corporation or
other entity) for a period of twelve (12) months from the date of such
termination in connection with (a) and (b) below and for a period of two (2)
years from the date of such termination in connection with (c) below, directly
or indirectly:

      (a)   Call upon, solicit, divert or attempt to take away any of the
            customers or business of GES, Exhibitgroup/Giltspur or any of their
            affiliated companies (collectively, "Companies"); provided, however
            that such activity shall not be deemed a violation of this covenant
            if on behalf of an entity not in direct or indirect competition with
            the Companies;
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Mr. Paul B. Mullen
March 1, 2000
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      (b)   Induce or attempt to induce any employee of Companies to discontinue
            their employment with any of the Companies; or

      (c)   Disclose, make available or divulge to any corporation, partnership,
            individual, firm, other business or person any trade secrets,
            customer lists, business policies, pricing of services, financial
            information or other confidential or secret information concerning
            the business and affairs of the Companies, except: (1) information
            or knowledge which may now be in or subsequently may come into the
            public domain other than by way of unauthorized disclosure by you or
            anyone else owing a nondisclosure or confidentiality obligation to
            Employer; (2) information consisting of nothing more than the
            product of ordinary skill generally expected of comparable employees
            in the industry; or (3) information or knowledge which you are
            required to disclose by order of a governmental agency or court, if
            you notify Employer in advance of the disclosure requirement and
            reasonably assists Employer in obtaining protective orders or other
            available assurances of confidentiality if Employer so requests.

      You acknowledge that if your employment with Employer terminates for any
reason, you will be able to earn a livelihood without violating the foregoing
restrictions and that your ability to earn a livelihood without violating such
restrictions is a material condition to your employment with Employer.

      6. Additional Consideration. Upon termination of your employment by you or
Employer, Employer shall pay to you as severance and as further compensation for
the above covenant not to compete twelve (12) months base compensation at your
then current salary as follows:

      (a)   The payment shall be made monthly over an twelve (12) month period
            in accordance with the payroll practices of Employer. In no event
            shall you be obligated to seek other employment or take any other
            action to mitigate the amounts payable to you under this Agreement.
            However, at the sole option of the Employer, the Employer may elect
            instead to pay you a termination payment equal to the present value
            of the aggregate amount of base salary compensation that would have
            been payable to you over salary continuation period. In either
            event, you shall be entitled to continue to be covered over such
            eighteen (18) month period by all fringe benefits or perquisites to
            which you were entitled as of the date of termination, at the same
            coverage levels and on the same terms and conditions which applied
            immediately prior to the date of your termination of employment;

      (b)   Any Bonus to which you would have become entitled under paragraph 3,
            prorated, as applicable, except in the event of termination for
            cause pursuant to
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Mr. Paul B. Mullen
March 1, 2000
Page 4

            subparagraph 7(a);

      (c)   All of your stock options in the Employer's stock option plan shall
            become immediately and fully vested and exercisable if termination
            is elected by Employer, except in the event of termination for cause
            pursuant to subparagraph 7(a); and

      (d)   During the salary continuation period pursuant to subparagraph 6(a),
            you and your spouse and dependents shall be entitled to continue to
            be covered by all group medical, health, dental and accident
            insurance or other such health care arrangements in which you were a
            participant as of the date of termination, at the same coverage
            levels and on the same terms and conditions which applied
            immediately prior to the date of your termination of employment;
            provided, however, that if, as the result of the termination of your
            employment, you and/or your otherwise eligible dependents or
            beneficiaries shall become ineligible for benefits under any one or
            more of the Employer's benefit plans, the Employer shall continue to
            provide you and your eligible dependents or beneficiaries, through
            other means, with benefits at a level at least reasonably equivalent
            to the level of benefits for which you and your dependents and
            beneficiaries were eligible under such plans immediately prior to
            the date of your termination of employment. At the termination of
            the benefits coverage under the preceding sentence, you and your
            spouse and dependents shall be entitled to continuation coverage as
            required by the Consolidated Omnibus Budget Reconciliation Act of
            1985, as amended ("COBRA") or under any other applicable law, as if
            you had terminated employment with the Employer on the date such
            benefits coverage terminates.

      7.    Termination.

      (a)   Termination for Cause. Employer may suspend or terminate this
            Agreement without additional compensation and your employment at any
            time should you:

            (1)   Become incapable for more than 180 days of satisfactorily
                  performing the duties required of your position due to
                  personal injury or other physical or mental illness or
                  disease;

            (2)   Engage in activities that would constitute a material conflict
                  of interest with Employer, GES or GES' subsidiaries;

            (3)   Be convicted of a felony, or a crime of moral turpitude, fraud
                  or dishonesty, or commit an act which, in the reasonable
                  judgment of a majority of Employer's Board of Directors,
                  subjects Employer, GES or GES' subsidiaries to public
                  disrespect, scandal or ridicule or adversely and
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Mr. Paul B. Mullen
March 1, 2000
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                  materially affects the utility of your services to Employer or
                  GES; or

            (4)   Knowingly disregard or violate any instruction or policy
                  established by Employer or GES with respect to the operation
                  of the business and affairs of Employer, GES or GES's
                  subsidiaries; provided, however that such instruction or
                  policy does not require the commission of an act prohibited by
                  law or which is in violation of the terms of this Agreement.

      (b)   Termination by Employee With Good Reason. Notwithstanding anything
            to the contrary in this Agreement, whether express or implied,
            subject, however, to the fulfilment of the obligations set forth in
            paragraph 5 above, you may, at any time, resign from employment with
            Employer With Good Reason. In the event your employment hereunder is
            terminated by you for Good Reason (as defined below), you shall be
            entitled to receive:

            (1)   Your base salary compensation and additional consideration as
                  you would have received such amounts during the period as
                  defined in Paragraph 6, as if you were still employed
                  hereunder.

            (2)   For the purposes of this Agreement, "Good Reason" shall mean
                  the occurrence of any one or more of the following events
                  unless such events are fully cured within thirty (30) days
                  following written notification by you to the Employer that you
                  intend to terminate your employment hereunder for one or more
                  of the reasons set forth below:

                  (i)      a material breach by GES or Employer of any material
                           provision of this Agreement, including but not
                           limited to, the assignment to you of any duties
                           inconsistent with your position or duties of
                           employment;

                  (ii)     assignment to you of any duties materially and
                           adversely inconsistent with your position and
                           responsibilities;

                  (iii)    the Employer's requiring you to be based anywhere
                           other than in the geographic area specified in
                           Paragraph I without your written authorization;

                  (iv)     any decrease during the Term in your Base
                           Salary compensation; or

                  (v)      the failure of a successor company to assume this
                           Agreement, if such assumption is requested by you.

      (c)   Nondisparagement. Following the termination of employment in
            accordance with this paragraph 7, you will not take any action which
            disparages Companies, or their respective officers, directors,
            shareholders, agents or employees nor will you
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Mr. Paul B. Mullen
March 1, 2000
Page 6

            make any verbal or written disparaging statements. Further,
            Companies will not take any action which disparages you, nor will
            Companies. make any verbal or written statements which disparage you
            and will use its reasonable best efforts to ensure that none of its
            officers, directors, shareholders, agents or employees make any
            verbal or written statements which disparage you.

      8. Further Assistance. During and after the term of this Agreement, you
agree to cooperate with and assist Employer and GES as reasonably requested by
Employer, at Employees expense, in any lawsuit, action, litigation, proceeding,
claim or dispute with any third party that may arise involving GES's business;
including, but not limited to, any lawsuit, action, litigation, proceeding,
claim or dispute arising from allegations that operation of such business
infringes the patent, trade secret or other intellectual property rights of any
third party. After expiration of the salary continuation period defined in
paragraph 6, Employer shall pay you reasonable fees pursuant to your providing
such assistance.

      9.Remedies. You acknowledge that a breach of the provisions of this
Agreement irreparably and continually will harm Companies or their assigns, and
that money damages may not be adequate. Consequently, you agree that if you
breach or threaten to breach any of the restrictions herein, Companies shall be
entitled to both a preliminary and permanent injunction in order to prevent the
continuation of such harm. Nothing herein shall be construed to prohibit
Companies from also pursuing other remedies, the parties having agreed that all
remedies shall be cumulative.

      10. Settlement by Arbitration. Employer and you agree that, except for the
claims of either party hereto for injunctive relief, specific performance or any
other equitable remedy, any claim or controversy that arises out of or relates
to this Agreement, or the breach of it by either party, will be settled by
arbitration in the State of Nevada, in accordance with the Employment Dispute
Resolution Rules of the American Arbitration Association. The arbitrator
mutually selected by the parties shall reside in Nevada or California.

      11.   General Provisions.

      (a)   Entire Agreement. This Agreement constitutes the entire agreement
            and understanding with respect to your employment by Employer and
            supersedes any and all prior agreements and understandings, whether
            oral or written, relating thereto. Notwithstanding the foregoing,
            nothing in this Agreement shall prevent or limit your participation
            in any benefit, bonus, incentive or other plan, program, policy, or
            practice provided by the Employer and for which you may qualify.
            Amounts which you are otherwise entitled to receive under any plan,
            practice, policy or program of the Employer and any other payment or
            benefit required by law at or subsequent to your effective date of
            termination shall be payable in
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Mr. Paul B. Mullen
March 1, 2000
Page 7

            accordance with such plan, practice, policy or program or applicable
            law except as explicitly modified by this Agreement. This Agreement
            shall not be modified or amended except by written agreement signed
            by both you and the Employer.

      b)    Modification of Restrictions. The parties have attempted to limit
            your right to compete in this Agreement only to the extent necessary
            to protect the Companies from unfair competition. The parties
            recognize, however, that reasonable people may differ in making such
            a determination. Consequently, the parties hereby agree that, if the
            scope or enforceability of the restrictive covenant is in any way
            disputed at any time, a court or other trier of fact may modify and
            enforce the covenant to the extent that it believes to be reasonable
            under the circumstances existing at that time.

      (c)   Severability. If any provision of this Agreement is adjudged by any
            court to be void or unenforceable in whole or in part, this
            adjudication shall not affect the validity of the remainder of the
            Agreement.

      (d)   Governing Law. This Agreement shall be governed by, and construed
            and enforced in accordance with the laws of Nevada (without giving
            effect to choice of law or conflict of law principles), except to
            the extent governed by federal law, irrespective of the fact that
            one or more of the parties now is, or may become, a resident or
            citizen of a different state or country.

      (e)   Survival. The obligations imposed upon you in paragraphs 5, 6, 8, 9
            and 10 shall survive termination of this Agreement or your
            employment with Employer.

      (f)   Assigns. This Agreement shall be binding upon and shall inure to the
            benefit of the successors and assigns of Employer, but shall not be
            assignable by you.

      (g)   Notices. Any notice permitted or required hereunder shall be in
            writing and shall be deemed to have been given on the date of
            delivery or, if mailed by registered or certified mail, prepaid, on
            the date of mailing. If to you at the above address, or if to
            Employer at the above address, attention: General Counsel. Either
            party may, by notice to the other, change his or its address for
            notice hereunder.
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Mr. Paul B. Mullen
March 1, 2000
Page 8

      If you accept employment on the terms and conditions set forth in this
letter, please indicate by your signature in the space provided and return one
copy to me.

                                    Very truly yours,

                                    By:   /s/   Robert H. Bohannon
                                          -------------------------------------
                                                Chairman, President and
                                                Chief Executive Officer

ACCEPTED AND AGREED on this
11th day of April, 2000.

/s/   Paul B. Mullen
--------------------------
Paul B. Mullen<PAGE>   1
                                                                     Exhibit 10B

              AMENDMENT DATED MAY 9, 2000 TO VIAD CORP SUPPLEMENTAL
                                  PENSION PLAN

Section 13 of the Viad Corp Supplemental Pension Plan shall be amended by
addition of the following in its place:

SECTION 13  NON-COMPETE AND FORFEITURE PROVISIONS:

"Notwithstanding any other provision in this Plan to the contrary, from and
after January 1, 2000, an Eligible Employee's right to receive a benefit or
future benefits under this Plan shall be governed by the following provisions:

(a)   The right shall be conditioned upon certification by the Eligible Employee
      prior to their receipt of any future benefits under this Plan that the
      Eligible Employee has read and understands the non-compete and forfeiture
      provisions set forth in this Section 13, and that the Eligible Employee
      has no intent to engage in any activity or provide any services which are
      contrary to the spirit and intent of these provisions. The Eligible
      Employee's failure to so certify shall not constitute a waiver on the part
      of the Company as to the enforceability of these provisions under Section
      13.

(b)   In order to better protect the goodwill of the Company and its
      subsidiaries and to prevent the disclosure of the Company's or its
      subsidiaries' trade secrets and confidential information and thereby help
      insure the long-term success of the business, the Eligible Employee,
      without prior written consent of the Company, will not engage in any
      activity or provide any services, whether as a director, manager,
      supervisor, employee, adviser, agent, consultant, owner of more than five
      (5) percent of any enterprise or otherwise, for a period of two (2) years
      following the date of the Eligible Employee's termination of employment
      with the Company, or its subsidiaries, in connection with the manufacture,
      development, advertising, promotion, design, or sale or any other activity
      in furtherance of any business enterprise, service or product which is the
      same as or similar to or competitive with or in any way adverse to any
      services or products or other activities of the Company or its
      subsidiaries (including both existing services or products as well as
      services or products known to the Eligible Employee, as a consequence of
      the Eligible Employee's employment with the Company or one of its
      subsidiaries, to be in development):

      (1)   with respect to which the Eligible Employee's work has been directly
            concerned at any time preceding termination of employment with the
            Company or any of its subsidiaries, or

      (2)   with respect to which during that period of time the Eligible
            Employee, as a consequence of the Eligible Employee's job
            performance and duties, acquired knowledge of the trade secrets or
            other confidential information of the Company or its subsidiaries.
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For purposes of this Section 13, it shall be conclusively presumed that the
Eligible Employee has knowledge of information he or she was directly exposed to
through actual receipt or review of memos or documents containing such
information, or through actual attendance at meetings at which such information
was discussed or disclosed.

(c)   If, at any time during the two (2) year period after the Eligible
      Employee's termination of employment from the Company or any of its
      subsidiaries, the Eligible Employee engages in any conduct described in
      Section (b) above, then the amount of any payments made to the Eligible
      Employee from the Plan during that period (without regard to tax effects)
      shall be paid by the Eligible Employee to the Company. The Eligible
      Employee consents to the deduction from any amounts the Company or any of
      its subsidiaries owes the Eligible Employee from time to time to the
      extent of the amount the Eligible Employee owes the Company hereunder.

                                        2

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