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                                                                   Exhibit 10.13

                            STERLING COMMERCE, INC.

                    SUPPLEMENTAL EXECUTIVE RETIREMENT PLAN
                    --------------------------------------

                                   PREAMBLE
                                   --------


The purpose of this Supplemental Executive Retirement Plan is to continue the
benefits accrued for Warner C. Blow under the Informatics General Corporation
Supplemental Executive Retirement Plan II (the "Prior Plan"). This Plan amends
and supersedes, effective as of January 1, 1997, the Prior Plan in its entirety
with respect to the Prior Plan benefits of Warner C. Blow.


                                   SECTION I
                                   ---------

                                  Definitions
                                  -----------

1.1    "Basic Plan Benefit" has the meaning set forth in Section 3.1.

1.2    "Change in Control Agreement" means the Change in Control and Severance
       Agreement between the Company and the Participant, effective February 12,
       1996, as well as any amendments made to such agreement.

1.3    "Code" means the Internal Revenue Code of 1986, as may be amended from
       time to time.

1.4    "Committee" means the Executive Committee of the Board of Directors of
       the Company (excluding, however, the Participant), which has been given
       authority by the Board of Directors to administer this Plan.

1.5    "Company" means Sterling Commerce, Inc., a Delaware corporation.

1.6    "CPI" means the Consumer Price Index or appropriate equivalent index as
       determined by the Committee.

1.7    "Earnings" means base salary payable plus cash incentive compensation
       payable for a calendar year, but excluding all incentive cash
       compensation in excess of 50% of base salary in the calendar year in
       which such incentive awards are received by the Participant or, if the
       Participant elects to defer receipt of all or part of such incentive
       awards pursuant to the Company's Deferred Compensation Plan or otherwise,
       in the calendar year in which such incentive awards first would have been
       otherwise received by the Participant, all such amounts averaged over the
       highest consecutive three calendar years of Service. Notwithstanding any
       provision contained herein, the limitation for recognition of incentive
       cash compensation as "Earnings" contained in the previous sentence shall
       be applied to the Participant's base salary for his last full calendar
       year of Service in

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       determining such limitation with respect to the Participant's incentive
       compensation for his last full calendar year of Service. Salary deferred
       by the election of the Participant pursuant to the Company's Deferred
       Compensation Plan or otherwise shall be included in Earnings in the
       calendar year for which such salary relates (i.e., the year in which the
       related services are performed), cash incentive compensation so deferred
       shall be included in Earnings in the calendar year in which, but for such
       deferral, such incentive compensation first would have been received, and
       deferred compensation (both salary and incentive compensation) that is
       included in Earnings pursuant to this sentence shall not be included in
       Earnings when it is later actually received by the Participant. For
       example, annual incentive cash compensation is earned in calendar year
       1995 in the amount of $80,000 and is paid in calendar year 1996. The
       $80,000 paid in 1996 is compared to a $120,000 1996 base salary. Since
       $80,000 is greater than $60,000 (50% of 1996 base salary) only $60,000 of
       the award will be used towards Earnings for 1995 under the Plan. The
       Earnings for 1995 would be the same even if the Participant deferred
       receipt of all or a portion of the $80,000 or $120,000 until some time
       after 1996. As used herein, "monthly Earnings" means one-twelfth of
       Earnings.

1.8    "Informatics Plan" means the Informatics General Corporation Retirement
       Plan II, a terminated money purchase pension plan.

1.9    "Participant" means Warner C. Blow.

1.10   "Plan" means the Sterling Commerce, Inc. Supplemental Executive
       Retirement Plan.

1.11   "Retirement" means the termination of the Participant's employment with
       the Company on one of the retirement dates specified in Section 2.1.

1.12   "Service" means the Participant's months of service from September 30,
       1974, his date of hire by Informatics General Corporation, to Retirement.
       Such service will include without duplication periods of employment with
       Informatics General Corporation; Sterling Software, Inc.; the Company;
       and any of their subsidiaries, affiliates, or successors. If the
       Participant becomes disabled and is receiving long-term disability
       benefits from the Company's Long-Term Disability Plan, such period shall
       be considered Service under this Plan.

1.13   "Severance Agreement" means the Severance Agreement between the Company
       and the Participant, dated February 12, 1996, as well as any amendments
       made to such agreement.

1.14   "Surviving Spouse" means the Participant's spouse married to him for at
       least one year prior to the earlier of the Participant's death or
       Retirement.

1.15   The singular may include the plural, unless the context clearly indicates
       the contrary. 

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                                   SECTION II
                                   ----------

                            Eligibility for Benefits
                            ------------------------


2.1    Subject to Section IV of this Plan, the Participant is eligible to retire
       and receive a benefit under this Plan beginning on one of the following
       dates.

       (a)  "Normal Retirement Date," which is the first day of the month
            following the month in which the Participant reaches age 65.

       (b)  "Early Retirement Date," which is the first day of any month
            hereafter before the Normal Retirement Date or Disability Retirement
            Date.

       (c)  "Postponed Retirement Date," with the Committee's consent, which is
            the first day of the month following the Participant's Normal
            Retirement Date in which the Participant terminates employment with
            the Company.

       (d)  "Disability Retirement Date," which is the first day of the month in
            which the Participant begins receiving a long-term disability
            benefit from the Company's Long-Term Disability Plan.

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<PAGE>
 
                                  SECTION III
                                  -----------

                               Amount of Benefit
                               -----------------


3.1    The monthly retirement benefit payable to the Participant if he retires
       at his Normal Retirement Date or his Postponed Retirement Date under the
       Plan will equal the lesser of (i) or (ii), where

       (i)  is equal to 1/6 of 1% times Service times monthly Earnings; and

       (ii) is equal to 50% of monthly Earnings less the Basic Plan Benefit (as
            hereinafter defined).

       For purposes of the Plan, the term "Basic Plan Benefit" means the monthly
       annuity payment (as hereinafter determined), payable (x) in the form of a
       50% joint and survivor annuity to the Participant if he has a Surviving
       Spouse at the Normal Retirement Date or Postponed Retirement Date; or (y)
       if the Participant does not have a Surviving Spouse at such time, in the
       form of a single life annuity, that could be provided by the sum of:

       (a) $241,425 (which is equal to the accumulation with interest of 3% of
           Compensation for each calendar year of the Participant's Service
           beginning with the calendar year in which he first participated in
           the Informatics Plan and ending on December 31, 1995), together with
           interest on such amount at the Applicable Rate (as hereinafter
           defined) from January 1, 1996 to the later of the Participant's
           Normal Retirement Date or his Postponed Retirement Date; and

       (b) with respect to each calendar year of the Participant's Service after
           December 31, 1995, the accumulation (with interest thereon at the
           Applicable Rate) of 3% of Compensation for each such calendar year to
           the later of the Participant's Normal Retirement Date or his
           Postponed Retirement Date.

       For purposes of this Section, (1) the term "Applicable Rate" means an
       annual rate of interest equal to 5%; (2) the term "Compensation" means
       the Participant's taxable wages as reported on Form W-2 up to any limit
       under Section 401(a)(17) of the Code or any successor provision; and (3)
       all annuity amounts will be determined by using the annual rate of
       interest on 30-year Treasury securities for the month of November
       preceding the calendar year in which benefit payments begin and the
       applicable mortality table as prescribed by the Secretary of the Treasury
       under Section 417(e)(3) of the Code or any successor provision.

3.2    The monthly benefit payable to the Participant if he retires on an Early
       Retirement Date will equal the benefit determined in Section 3.1, except
       that the benefit described in Section 3.1(ii) will be multiplied by a
       fraction, the numerator of which is Service as of his

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       Early Retirement Date and the denominator of which is his Service
       projected to his Normal Retirement Date. For example, if the Participant
       was 35 when hired and retired early at age 55, his annual benefit would
       be determined as the lessor of (i) or (ii), where

       (i)  is equal to 1/6 of 1% times Service at Early Retirement Date times
            monthly Earnings at Early Retirement Date; and

       (ii) is equal to 33-1/3% of monthly Earnings less the Basic Plan Benefit;

       where 33-1/3% is equal to 50% multiplied by the fraction 240/360; and
       where 240 is his Service to age 55 and 360 is the service he would have
       had if he had continued to work to age 65, his Normal Retirement Date.
       The monthly benefit determined under this Section 3.2 will become payable
       on the Participant's Normal Retirement Date. For purposes of determining
       the Basic Plan Benefit under this section, all amounts to be determined
       under paragraphs (a) and (b) of Section 3.1 shall be determined as of the
       Participant's Early Retirement Date. At the Committee's discretion,
       payments may begin any time after the Participant's Early Retirement Date
       and prior to his Normal Retirement Date and such monthly benefit shall be
       actuarially reduced based on the interest and mortality assumptions
       contained in clause (3) of the last sentence of Section 3.1.

3.3    The monthly benefit payable at a Postponed Retirement Date, will be equal
       to the monthly benefit determined in accordance with Section 3.1 based on
       Service, Earnings, and the Participant's Basic Plan Benefit, as of the
       Participant's Postponed Retirement Date.

3.4    If the Participant becomes disabled and if he receives long-term
       disability benefits from the Company's Long-Term Disability Plan, the
       monthly benefit payable at Normal Retirement Date to the Participant
       under this Plan will be equal to the monthly benefit determined in
       accordance with Section 3.1 based on Service to Normal Retirement Date
       and Earnings and the Participant's Basic Plan Benefit as of the
       Participant's date of disability.

3.5    The monthly benefit payable at a Disability Retirement Date, will be
       equal to 66-2/3% of the Participant's monthly Earnings as of his
       Disability Retirement Date, in excess of $7,500. Such benefit, payable
       monthly, shall commence on the date the Participant begins receiving a
       long-term disability benefit from the Company's Long-Term Disability Plan
       and will be payable as long as the Participant continues to receive a
       long-term disability benefit from such plan. Benefits from this Plan,
       payable as a result of a disability, will stop when benefits from the
       Long-Term Disability Plan cease. At age 65, benefits will commence in
       accordance with Section 3.4.

3.6    The benefits payable under the Plan, as determined in accordance with the
       appropriate preceding section of this Section III, except those
       determined in accordance with Section 3.5, will be payable in equal
       monthly installments, adjusted if appropriate as provided in 

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       Section 3.7, during the Participant's lifetime with benefits ceasing upon
       the Participant's death; however, if, at the time of the Participant's
       death, he has a Surviving Spouse, such Surviving Spouse shall receive a
       benefit equal to 50% of the Participant's benefit as so adjusted,
       commencing on the first day of the month following the later of the month
       in which the surviving Spouse reaches age 55 or the month in which the
       Participant dies with such payments continuing to the death of the
       Surviving Spouse.

3.7    Any benefits payable hereunder, except those determined in Section 3.5,
       shall be adjusted upward annually, effective each March 1, beginning with
       the March 1 occurring at least 12 months after entitlement to benefit
       payments first occurs, to the extent that the CPI for the preceding
       calendar year exceeds a 5% increase from the next preceding calendar
       year.

       Any benefits payable hereunder shall be adjusted downward annually,
       effective each March 1, beginning with the March 1 occurring at least 12
       months after entitlement to benefit payments first occurs, to the extent
       that any decrease in the CPI for the preceding calendar year over the CPI
       for the next preceding calendar year exceeds 5%; provided, however, that,
       in no event shall the Participant's monthly benefit be less than the
       monthly benefit paid to him during the first month after entitlement to
       benefit payments first occurs.

3.8    To the extent that the Participant's employment is terminated in a manner
       that entitles him to severance benefits under the provisions of the
       Severance Agreement, (a) his benefit under this Plan shall be calculated
       by giving the Participant credit as Service the number of months for
       which the Participant is entitled to severance benefits pursuant to the
       terms of the Severance Agreement; and (b) any severance benefits to which
       the Participant is entitled pursuant to the terms of the Severance
       Agreement shall not be included in the calculation of "Earnings."

3.9    In the event of a Change in Control (as hereinafter defined), the
       following provisions shall apply to the Participant's benefit under this
       Plan:

       (a) his monthly benefit shall be calculated by (i) giving the Participant
           credit as Service the number of months for which the Participant is
           or would be entitled to severance benefits upon termination of his
           employment following a Change in Control pursuant to the terms of the
           Change in Control Agreement and (ii) giving the Participant credit
           for Earnings during each such year of Service at the rate of Earnings
           in effect for the year in which the Change in Control occurred;

       (b) except as provided in paragraph (a) above, no benefits to which the
           Participant is entitled as a result of termination of his employment
           following a Change in Control pursuant to the terms of the Change in
           Control Agreement shall be included in Earnings;

       (c) the present value of his benefit at the time of the Change in Control
           (determined 

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           by using his Service, Earnings and Basic Plan Benefit as of such date
           (including any adjustments required under paragraphs (a) and/or (b)
           above) and the interest and mortality assumptions contained in clause
           (3) of the last sentence of Section 3.1) shall be paid to the
           Participant in a single lump sum payment on the first day of the
           month following the Change in Control; and

       (d) a Gross-Up Payment (as defined in the Change in Control Agreement)
           with respect to any portion of the payment required under paragraph
           (c) of this Section 3.9 that is determined to be subject to Excise
           Tax (as defined in the Change in Control Agreement) shall be paid to
           the Participant in a single lump sum payment on the first day of the
           third month following the occurrence of the Change in Control, but
           only to the extent that the payment required under such paragraph (c)
           is not taken into account in determining the amount of the
           Participant's Gross-Up Payment under the Change in Control Agreement.

       To the extent that the Participant's employment is terminated upon a
       Change in Control, the provisions of this Section 3.9 shall supersede the
       provisions of Section 3.8 in determining the treatment of the
       Participant's benefit under this Plan.

       As used in this Plan, the term "Change in Control" means a Change in
       Control as defined in the Change in Control Agreement (whether or not
       such agreement has been terminated or has expired), except that "50%"
       will be substituted for "20%" in Section 1(b)(iii) of the Change in
       Control Agreement. 

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<PAGE>
 
                                   SECTION IV
                                   ----------

                         Payment of Retirement Benefits
                         ------------------------------


4.1    Benefits payable in accordance with Section III, except Section 3.5, will
       commence on the Participant's Normal or Postponed Retirement Date or upon
       a date determined by the Committee in accordance with Section 3.2. The
       last payment will be on the first day of the month in which the
       Participant dies unless he has a Surviving Spouse in accordance with
       Section 3.6.

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                                   SECTION V
                                   ---------

                             Death Benefits Payable
                             ----------------------


5.1    If the Participant dies before Retirement, excluding Disability
       Retirement, his Surviving Spouse will receive a monthly benefit equal to
       50% of the amount of the Participant's monthly benefit determined in
       accordance with Section 3.1 as if the Participant had retired and
       commenced receiving a benefit on the first day of the month following the
       date of his death.

5.2    A surviving Spouse's benefits will be payable monthly, and will commence
       on the first day of the month following the later of the month in which
       the Surviving Spouse reaches age 55 or the month in which the Participant
       dies. The last payment will be on the first day of the month in which the
       Surviving Spouse dies.

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                                   SECTION VI
                                   ----------

                                 Miscellaneous
                                 -------------


6.1    Nothing contained herein will confer upon the Participant the right to be
       retained in the service of the Company, nor will it interfere with the
       right of the Company to discharge or otherwise deal with the Participant
       without regard to the existence of this Plan.

6.2    The Committee shall establish a trust fund to provide for contributions
       made by the Company to satisfy its obligations to the Participant under
       this Plan. Except as may be provided in the agreement governing such
       trust, all assets held in the trust shall be assets of the Company
       subject to its general creditors.

6.3    To the maximum extent permitted by law, no benefit under this Plan shall
       be assignable or subject in any manner to alienation, sale, transfer,
       claims of creditors, pledge, attachment, or encumbrance of any kind.

6.4    The Committee may adopt rules and regulations to assist it in the
       administration of the Plan.

6.5    The Participant shall receive a copy of this Plan and the Committee will
       make available for inspection by the Participant a copy of the rules and
       regulations used by the Committee in administering the Plan.

6.6    The Plan will be construed and governed in all respects in accordance
       with applicable federal law and, to the extent not preempted by such
       federal law, in accordance with the laws of the State of Texas, including
       without limitation, the Texas statute of limitations, but without giving
       effect to the principles of conflicts of laws of such State.


                                 STERLING COMMERCE, INC.



                              By  /s/ ALBERT K. HOOVER
                                 ------------------------------------------

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