<PAGE>

                                 EXHIBIT 10.84


                  FIRST AMENDMENT TO LEASE AGREEMENT FOR THE

                               COMDATA BUILDING
<PAGE>

                           FIRST AMENDMENT TO LEASE
                           ------------------------

     This First Amendment to Lease (the "Amendment") has been entered into as of
the 19th day of October, 2000, by and between THE NORTHWESTERN MUTUAL LIFE
INSURANCE COMPANY, a Wisconsin corporation, having its principal business
address located at 720 East Wisconsin Avenue, Milwaukee, Wisconsin 53202
("Lessor") and COMDATA NETWORK, INC., a Maryland corporation, having its
principal business address located at 5301 Maryland Way, Brentwood, TN, 37027
("Lessee").

     WHEREAS, Lessor and Lessee entered into that certain Lease Agreement dated
as of June 20, 1996 (the "Lease") under the terms of which Lessee leased the
Leased Premises (as defined in the Lease);

     WHEREAS, Lessor desires to sell the Leased Premises to a third party and is
marketing the Leased Premises for sale; and

     WHEREAS, Lessor and Lessee wish to extend and amend the Lease effective as
of the date of a sale to a third party to make the Leased Premises more
marketable.

     NOW, THEREFORE, for mutual consideration, the receipt and sufficiency of
which are hereby acknowledged, and intending to be legally bound hereby, Lessor
and Lessee agree as follows:

     1.  All capitalized terms used herein which are not defined herein shall
have the meanings ascribed to them in the Lease.

     2.  The terms of this Amendment shall be effective only in the event that
Lessor conveys the Leased Premises to a third party, and shall be effective from
and after the date on which such a conveyance occurs (the "Sale Date").

     3.  The first sentence of Article IV of the Lease is hereby replaced, in
its entirety, with the following:

     The term of the Lease shall commence on the Commencement Date and shall end
     on the date which is fifteen (15) years from the last day of the month in
     which the Sale Date occurs (the "Lease Term").

     4.  Article XXXII of the Lease is hereby replaced, in its entirety, with
the following:

                                 ARTICLE XXXII
                           ASSIGNMENT AND SUBLETTING

         32.1  Lessee shall not assign, transfer, mortgage or otherwise encumber
     this Lease or all or substantially all of Lessee's rights hereunder or
     interest herein or
<PAGE>

     sublet all or substantially all of the Leased Premises without obtaining
     the prior written consent of Lessor, which consent shall not be
     unreasonably withheld or delayed. No assignment or transfer of this Lease
     or the right of occupancy hereunder may be effectuated by operation of law
     or otherwise without the prior written consent of Lessor, which consent
     shall not be unreasonably withheld or delayed. Lessee's consent to any
     assignment, subletting or occupancy shall not be construed as relieving
     Lessee or any assignee, subtenant or occupant from the obligation of
     obtaining Lessor's prior written consent to any subsequent assignment,
     subletting or occupancy. Provided that Lessee is not in default hereunder,
     Lessor expressly consents to Lessee's assignment or subletting of the
     Leased Premises, or any part thereof, to any parent, subsidiary or
     affiliate of Lessee or of Ceridian Corporation.

          32.2  If at any time during the Lease Term Lessee desires to transfer,
     assign or sublet all or substantially all of the Leased Premises, then in
     connection with Lessee's request to Lessor for Lessor's consent thereto,
     Lessee shall give notice to Lessor in writing of the identity of the
     proposed assignee or subtenant and its business, the terms of the proposed
     assignment or subletting and the commencement date of the proposed
     assignment or subletting. Lessee shall also transmit therewith the most
     recent financial statement or other evidence of financial responsibility of
     such assignee or subtenant. Within ten (10) business days after receipt by
     Lessor of Lessee's notice and information, Lessor shall reasonably approve
     or disapprove the subletting or assignment.

          32.3  No subletting or assignment shall relieve Lessee of Lessee's
     obligations under this Lease. The consent by Lessor to any assignment,
     subletting, or occupancy shall not be construed as a waiver or release of
     Lessee from liability for the performance of any covenant or obligation to
     be performed by Lessee under this Lease, nor shall the collection or
     acceptance of Rent from any assignee, subtenant or occupant constitute a
     waiver or release of Lessee from any of its liabilities or obligations
     under this Lease.

          32.3  All restrictions and obligations imposed pursuant to this Lease
     on Lessee shall be deemed to extend to any subtenant, assignee, licensee,
     concessionaire or occupant of Lessee.

          32.4  Any attempted assignment or sublease by Lessee in violation of
     the terms and covenants of this Lease shall be null and void.

     5.   Article XXXIII of the Lease is hereby deleted in its entirety.

     6.   Article XXXIV of the Lease is hereby replaced, in its entirety, with
the following:

                                       2
<PAGE>

                                 ARTICLE XXXIV
                                   EXTENSION

          Lessee shall have one (1) option to extend the Lease under the same
     terms and conditions as provided herein for a five (5) year term,
     exercisable by providing Lessor written notice (the "Notice") of Lessee's
     intent to exercise the extension at least one year prior to the expiration
     date of the Lease Term.  The Base Rental for the renewal option period
     shall be calculated in accordance with the formula set forth on Exhibit D,
                                                                     ---------
     provided that Lessee shall have no obligation to extend pursuant to this
     Article XXXIV until the Base Rental for the option period is established
     and Lessee accepts such rate within sixty (60) days of Lessor's receipt of
     the Notice.

     7.  Exhibit D of the Lease is hereby replaced with the Exhibit D attached
hereto and made a part hereof.

     8.  Exhibit P of the Lease is hereby deleted in its entirety.  To the
extent that the Purchase Option Agreement set forth in Exhibit P was executed by
Lessor and Lessee, Lessor and Lessee hereby agree to terminate said Purchase
Option Agreement.

     9.  Lessor hereby agrees that, at Lessee's sole option, Lessor shall either
pay Lessee on the Sale Date the amount of $600,000.00 or shall provide Lessee,
on the Base Rental payment dates following the Sale Date, with a rent credit in
the aggregate amount of $600,000.00.

     10. The parties hereto hereby agree to execute and record the First
Amendment to Memorandum of Lease and Termination of Memorandum of Option
attached hereto as Exhibit A-1 and made a part hereof.

     11. Except as herein amended, the Lease remains in full force and effect.

     IN WITNESS WHEREOF, Lessor and Lessee have executed this First Amendment as
of the date first set forth above.

LESSOR:
------

THE NORTHWESTERN MUTUAL LIFE INSURANCE COMPANY, a Wisconsin corporation

By:  Northwestern Investment Management Company, a Wisconsin corporation, its
     wholly owned subsidiary and authorized representative

     By:/s/ Donald L. O'Dell
        ------------------------
        Donald L. O'Dell
        Its Managing Director
              SIGNATURES CONTINUED ON FOLLOWING PAGE

                                       3
<PAGE>

                    SIGNATURES CONTINUED FROM PREVIOUS PAGE
LESSEE:
------

COMDATA NETWORK, INC., a Maryland corporation

By:/s/ Jason Griska
   ---------------------------------
       Jason Griska
   ---------------------------------
   Its EVP, Finance
      ------------------------------


CONSENT OF GUARANTOR:

By its signature below, CERIDIAN CORPORATION, a Delaware corporation,
("Guarantor") the guarantor of the Lease under that certain Guaranty of Lease
dated as of June 20, 1996 (the "Guarantee"), hereby consents to the
modifications to the Lease set forth in this First Amendment.  Guarantor's
consent to said modifications shall not be deemed to be an amendment of the
provisions of section 2(a) of the Guarantee and Guarantor hereby agrees that its
consent shall not be required for the modifications set forth in this First
Amendment or in any future amendment of the Lease.

CERIDIAN CORPORATION, a Delaware corporation

By: /s/ Gary M. Nelson
   --------------------------------------
        Gary M. Nelson, Vice President
   --------------------------------------
   Its  General Counsel & Secretary
      -----------------------------------

                                       4
<PAGE>

                                  EXHIBIT A-1


Tennessee
RECORDING REQUESTED BY



WHEN RECORDED MAIL TO

The Northwestern Mutual Life Ins. Co.
720 East Wisconsin Ave. - Rm. N16WC
Milwaukee, WI 53202
Attn:  Rosemary Poetzel



            FIRST AMENDMENT TO MEMORANDUM OF LEASE AND TERMINATION
            ------------------------------------------------------
                        OF ORIGINAL MEMORANDUM OF LEASE
                        -------------------------------

     This First Amendment to Memorandum of Lease and Termination of Original
Memorandum of Lease (the "Amendment") has been entered into as of the ____ day
of ______________, 2000, by and between THE NORTHWESTERN MUTUAL LIFE INSURANCE
COMPANY, a Wisconsin corporation, having its principal business address located
at 720 East Wisconsin Avenue, Milwaukee, Wisconsin 53202 ("Lessor") and COMDATA
NETWORK, INC., a Maryland corporation, having its principal business address
located at 5301 Maryland Way, Brentwood, TN, 37027 ("Lessee").

     WHEREAS, Eakin & Smith, Inc., a Tennessee corporation, ("Eakin & Smith")
and Lessee entered into that certain Agreement of Lease dated as of November 29,
1988 (the "Original Lease"), and a Memorandum of Lease (the "Original Memorandum
of Lease") with respect to the Original Lease was recorded in Book 766, Page 238
in the Register's Office of Williamson County, Tennessee;

     WHEREAS, a second Memorandum of Lease (the "Memorandum of Lease") with
respect to the Lease was recorded in Book ______, Page ______ in the Register's
Office of Williamson County, Tennessee;

     WHEREAS, Lessor purchased the premises demised under the Original Lease
from Eakin & Smith and Lessor and Lessee terminated the Original Lease and
entered into that certain Lease Agreement dated as of June 20, 1996 (the "New
Lease") under the terms of which Lessee leased the Leased Premises (as defined
in the Lease); and

                                       5
<PAGE>

     WHEREAS, Lessor and Lessee have entered into that certain First Amendment
to Lease dated as of October 19, 2000.

     NOW, THEREFORE, for mutual consideration, the receipt and sufficiency of
which are hereby acknowledged, and intending to be legally bound hereby, Lessor
and Lessee agree as follows:

     1.  The Original Memorandum of Lease is hereby terminated as of the Sale
Date.

     2.  It is hereby acknowledged that the Agreement of Lease dated November
29, 1988 by and between Eakin & Smith and Lessee, as amended, was terminated and
replaced by that certain Lease Agreement dated as of June 20, 1996 by and
between Lessee and Lessor, as assignee of Eakin & Smith, demising the same
premises and additional premises (the "New Lease"), as amended by that certain
First Amendment to Lease dated as of October 19, 2000 (the "First Amendment") by
and between Lessor and Lessee (as amended, the "Amended New Lease"). All
references to the "Lease" in the Memorandum of Lease shall be deemed to refer to
the Amended New Lease. The terms of the Amended New Lease are as set forth
herein, and all provisions of the Memorandum of Lease and the Exhibit A attached
to the Memorandum of Lease are hereby deleted in their entirety and replaced
with the terms set forth herein.

     3.  The Amended New Lease demises the real property situated in Brentwood,
Williamson County, Tennessee, the legal description of which is attached hereto
as Exhibit A-1, and all improvements thereon (said land and said improvements
shall be known herein as the "Demised Premises").

     4.  The term of the Amended New Lease is fifteen (15) years from
_____________ [the last day of the month in which the conveyance of the premises
demised therein by Lessor to a third party occurs].  Lessee has one option to
extend the Amended New Lease for a five year term.  Such extension term is
subject to the terms and conditions set forth in the Amended New Lease.

     5.  The option to purchase provided for in the New Lease has been
terminated by the First Amendment.  There is no option to purchase or right of
first refusal in the Amended New Lease.

     6.  A true and correct copy of the New Lease and the First Amendment are
available for inspection at the office of Comdata Network, Inc., 5301 Maryland
Way, Brentwood, Tennessee, 37027.

     7.  NOW, THEREFORE, Lessor hereby grants, leases and demises unto Lessee
the Demised Premises together with all rights and privileges and appurtenances
thereto, and all buildings, improvements, equipment and other property now or
hereafter located on and within the Demised Premises, all subject to and in
accordance with the terms,

                                       6
<PAGE>

conditions and provisions of the Amended New Lease, all of which are
incorporated herein and made a part hereof by reference as fully and
particularly as if set out herein verbatim.

     8.  Except as herein amended, the Memorandum of Lease remains in full force
and effect. Lessor and Lessee hereby agree that this Amendment is solely for the
purpose of providing an instrument for recording, and in no way limits,
enlarges, supersedes or replaces any of the terms, covenants, conditions,
obligations, rights or remedies of Lessor or Lessee under the Amended New Lease.

     IN WITNESS WHEREOF, Lessor and Lessee have executed this Amendment as of
the date first set forth above.

LESSOR:
------

THE NORTHWESTERN MUTUAL LIFE INSURANCE COMPANY, a Wisconsin corporation

By:  Northwestern Investment Management Company, a Wisconsin corporation, its
     wholly owned subsidiary and authorized representative

     By:_______________________________
        _______________________________
        Its Managing Director

     Attest:___________________________
            ___________________________
            Its Assistant Secretary

LESSEE:
------

COMDATA NETWORK, INC., a Maryland corporation

By:_______________________________
   _______________________________
   Its____________________________

Attest:___________________________
       ___________________________
       ___________________________

                                       7
<PAGE>

STATE OF WISCONSIN    )
                      )ss.
COUNTY OF MILWAUKEE   )

On this ______ day of _____________, 2000, before me personally appeared
_________________ and _________________ with whom I am personally acquainted,
and who upon oath acknowledged themselves to be the Managing Director and
Assistant Secretary respectively, of Northwestern Investment Management Company,
a Wisconsin corporation, said corporation being known to me to be the authorized
representative of THE NORTHWESTERN MUTUAL LIFE INSURANCE COMPANY, the
corporation that executed the foregoing instrument, and acknowledged to me that
Northwestern Investment Management Company executed the same as such authorized
representative, and that they as such Managing Director and Assistant Secretary
respectively, being authorized so to do, executed the foregoing instrument for
the purposes therein contained, by signing the name of the corporation, as
authorized representatives, by themselves as Managing Director and Assistant
Secretary respectively, and by affixing thereto the common corporate seal of
such corporation.

WITNESS WHEREOF, I have hereunto set my hand and official seal.

My commission expires ___________________

                                                 _______________________________
                                                 Notary Public

                                       8
<PAGE>

STATE OF           )
                   )ss.
COUNTY OF          )

On this_______day of_____________, 2000, before me personally appeared
___________________ and __________________ with whom I am personally acquainted,
and who upon oath acknowledged themselves to be the ____________________ and
____________________, respectively, of COMDATA NETWORK, INC., a Maryland
corporation, and that as such ____________________ and _________________, being
authorized so to do, executed the foregoing instrument for the purposes therein
contained, by signing the name of the corporation by themselves as such
____________________ and _________________, and by affixing thereto the common
corporate seal of such corporation.

WITNESS WHEREOF, I have hereunto set my hand and official seal.

My commission expires

                                            ____________________________________
                                            Notary Public

                                       9
<PAGE>

                                  EXHIBIT A-1

             LEGAL DESCRIPTION OF ORIGINAL AND EXPANSION PROPERTY

                                       10
<PAGE>

                                   EXHIBIT D

                            BASE RENTAL CALCULATION
                            -----------------------

Monthly Base Rental payable during the initial Lease Term shall be determined as
follows:

     (a)  During the period from the Commencement Date until April 1, 1997, the
     Base Rental shall be $132,136.67 (which is one-twelfth of the product of
     (i) $15,856,400 multiplied by (ii) 10.00%).

     (b)  During the period from the April 1, 1997 through the end of the
     initial Lease Term, the Base Rental for the months during the remainder of
     the Lease Term shall be one-twelfth of the product of (i) $23,986,716.00,
     and (ii) the Rental Factor then in effect, as specified in the following
     table:

                Lease Year                      Rental Factor
                ----------                      -------------

                 1-5                              10.00%
                 6-10                             10.25%
                 11-15                            10.50%
                 15-End of Lease Term             10.75%

In the event that Lessee exercises the five (5) year option to extend the Lease
Term pursuant to Article XXXIV hereof, Base Rental for each month of the
extension period shall equal the greater of (i) the Base Rental in force during
the last Lease Year of the Lease Term, or (ii) 90% of the Market Rental Rate (as
hereafter defined and determined) as of the beginning of the last Lease Year of
the Lease Term.

As used herein, the "Market Rental Rate" shall be the fair market rental
(expressed in terms of dollars per square foot per month) for a lease of the
Leased Premises subject to the terms contained in the Lease for a term
equivalent to that of the extension option and shall be determined as follows:

          (i)  Upon Lessor's receipt of Lessee's written notice of its intent to
     exercise the option to extend pursuant to Article XXXIV of this Lease,
     Lessor and Lessee will consult with each other in an effort to arrive at
     the Market Rental Rate for the extension period. Any agreement as to the
     Market Rental Rate shall be set forth in a writing signed by Lessor and
     Lessee.

          (ii) If Lessor and Lessee fail to agree in writing on such Market
     Rental Rate within ten (10) days of Lessor's receipt of notice of Lessee's
     intent to exercise the option to extend, Lessor shall provide to Lessee a
     written appraisal ("Lessor's Appraisal") of the Market Rental Rate prepared
     by a Qualified

                                       11
<PAGE>

     Appraiser (as hereafter defined) selected by Lessor within thirty (30) days
     of expiration of the ten day period referred to above.

               (iii)  If Lessee agrees with Lessor's Appraisal, Lessee shall so
     notify Lessor in writing within thirty (30) days of its receipt thereof.
     If Lessee disagrees with Lessor's Appraisal, Lessee shall within thirty
     (30) days of its receipt of Lessor's Appraisal provide to Lessor a written
     appraisal ("Lessee's Appraisal") of the Market Rental Rate prepared by a
     Qualified Appraiser selected by Lessee.  Lessee's failure within such 30-
     day period to provide Lessor with either (A) written notice of its
     agreement with Lessor's Appraisal or (B) its own Lessee's Appraisal shall
     be conclusively deemed to mean that Lessee elects not to extend the Lease
     Term and thereafter Lessee shall have no further rights to extend the Lease
     Term pursuant to Article XXXIV.

               (iv)   If Lessee provides Lessor with Lessee's Appraisal within
     the 30-day period, and if the Market Rental Rate of Lessor's Appraisal is
     not more than 105% of Lessee's Appraisal, the Market Rental Rate shall be
     the average of the two appraisals.

               (v)    If Lessor's Appraisal is more than 105% of Lessee's
     Appraisal, Lessor's appraiser and Lessee's appraiser shall, within ten days
     of Lessee's delivery to Lessor of Lessee's Appraisal, choose a third
     Qualified Appraiser to make a third appraisal of the Market Rental Rate of
     the Property. If they are unable to select such third Qualified Appraiser
     within such ten day period, either party may apply to the head of the local
     unit of the American Arbitration Association (AAA) for appointment of the
     third Qualified Appraiser, and the selection by the AAA shall be
     conclusive. The Market Rental Rate shall then be the average of the two (2)
     appraisals closest to each other. If the appraisal of the third Qualified
     Appraiser is the average of the Lessor's Appraisal and the Lessee's
     Appraisal, the Market Rental Rate shall be the appraisal made by the third
     Qualified Appraiser.

Lessor and Lessee shall each pay the cost of its respective appraiser.  The
costs of the third Qualified Appraiser and the AAA shall be shared equally
between Lessor and Lessee.

As used in this Lease, a "Qualified Appraiser" shall be an appraiser who has
earned the MAI designation and who has at least seven (7) years of experience in
appraising commercial property in the Brentwood and Nashville, Tennessee area.

                                       12