William B. Conway Jr.
Illinova Corporation
500 South 27th Street
Decatur, Illinois 62521

Dear Mr. Conway:

         This letter is to confirm the terms of your  employment  with  Illinova
Corporation.

I.  Employment  Date.  Your first day of employment  will be April 12, 1999 (the
"Employment Date").

I. Salary. Your annual base salary will be $295,000,  subject to periodic review
to determine whether an increase is appropriate.

I.  Bonus.  You will be  entitled  to  participate  in the  Executive  Incentive
Compensation  Plan. Your bonus under the Executive  Incentive  Compensation Plan
will  be  $118,000  (which  is 40%  of  your  salary)  if the  target  level  of
performance is achieved,  and your bonus will be $177,000  (which is 60% of your
salary) at the maximum achievement level.

I. Long-Term  Incentive Award.  For 1999, your entire long-term  incentive award
will be in the form of a stock  option,  the terms of which are reflected in the
enclosed stock option agreement. The option will be granted as of the Employment
Date,  and the exercise price per share will be the fair market value of a share
of stock on the grant date.  After 1999, 50% of your long-term  incentive  award
will be made as a stock  option  grant,  and the  remaining  50% will be made as
performance share grant.

I. Supplemental Pension. In lieu of participation in the Company's  Supplemental
Executive  Retirement  Plan,  you will be covered by the  enclosed  Supplemental
Pension Plan.

I. Retention  Agreement.  You will be covered by the enclosed Employee Retention
Agreement, which provides benefits in the event of a Change in Control.

I. Loan.  To compensate  you for amounts you have  foregone by leaving  Troutman
Sanders LLP to join  Illinova  Corporation,  you will be entitled to a loan form
the Company of  $250,000.  The terms of the loan are  reflected  in the enclosed
letter and promissory note.

I. Lump Sum Death Benefits. If your death should occur while you are employed by
the  Company,  your  surviving  spouse  (or, if she does not  survive  you,  the
beneficiary  designated  by you) will be entitled to a lump sum death benefit of
two times the amount of your salary  plus your target  bonus at the time of your
death. In lieu of receiving this lump sum death benefit,  your surviving  spouse
may elect to receive the surviving spouse benefit under the Supplemental Pension


Plan. (If your spouse does not survive you, only the death benefit  described in
this paragraph is payable.  The  Supplemental  Pension Plan does not provide for
other survivor benefits.)

I. Termination.  You may resign from the Company at any time for any reason, and
the Board of Directors of the company may terminate your  employment at any time
for any reason.  At the time of your  termination  of  employment,  you (or your
estate)  will be entitled to the  compensation  and  benefits  specified in this
letter and the enclosed  material,  as well as to the other  benefits you earned
while employed by the Company,  to the extent such compensation and benefits are
payable on your termination of employment.

         If the  foregoing  reflects  your  understanding  of the  terms of your
agreement  with the Company,  please so indicate by signing and returning a copy
of this  letter  to the  undersigned,  along  with a signed  copy of each of the
enclosures.


                                                            Very truly yours,

                                                            Illinova Corporation



                                                            Charles E. Bayless

Accepted and agreed to this 13th day of April, 1999.



         William B. Conway Jr.

                      NON-QUALIFIED STOCK OPTION AGREEMENT
                              ILLINOVA CORPORATION
                   1992 LONG-TERM INCENTIVE COMPENSATION PLAN

     THIS AGREEMENT,  entered into as of the 12th day of April, 1999 (the "Grant
Date"),  by and  between  Illinova  Corporation,  an Illinois  corporation  (the
"Company") and William B. Conway Jr. (the "Employee"),

                                WITNESSETH THAT:

         WHEREAS,  the Company maintains the Illinova Corporation 1992 Long-Term
Incentive Compensation Plan (the "Plan"), which is incorporated and forms a part
of this  Agreement,  for the  benefit of key  employees  of the  Company and its
Subsidiaries;

         WHEREAS,  to induce the Employee to accept  employment  by the Company,
the Company has agreed to grant to the  Employee  the option  described  in this
Agreement; and

         WHEREAS,  the  Employee  and the  Company  desire  to enter  into  this
Agreement reflecting the award of such option;

         NOW,  THEREFORE,  IT IS AGREED,  by and  between  the  Company  and the
Employee as follows:

                                   SECTION ONE
                                      GRANT

         Subject to the terms and conditions of the Plan and this Agreement, the
Employee  is hereby  awarded an option to purchase  30,000  shares of Stock (the
"Option"). The Option is not intended, and shall not be treated, as an incentive
stock option (as that term is used in Section 422 of the Code).

                                   SECTION TWO
                                  OPTION PRICE

         The  option  price of each  share of stock  subject  to the  Option  is
$21.781.

                                  SECTION THREE
                            EXERCISE, EXPIRATION AND
                             CANCELLATION OF OPTION

         The Option shall be exercisable by the Employee in accordance  with the
following schedule:



If the Employee is employed through     The Option shall become exercisable with
       the following  date:               respect to the following number of 
                                          shares on and after that date:
- ------------------------------------ -------------------------------------------
One-year anniversary of Grant Date                  10,000 shares
- ------------------------------------ -------------------------------------------
Two-year anniversary of Grant Date                  10,000 shares
- ------------------------------------ -------------------------------------------
Three-year anniversary of Grant Date                10,000 shares
- ------------------------------------ -------------------------------------------

     If the  Employee's  employment by the Company  continues  through the 9-1/2
year  anniversary  of the Grant  Date,  then any  portion of the  Option  herein
granted  and  not  previously  exercisable  shall  become  exercisable  on  such
9-1/2-year anniversary.

     The Option shall expire as to any  unexercised  portion on the earliest of:

     (a) the tenth anniversary of the date first above written;

     (b) the first anniversary of the Employee's death;

     (c) five years following the Employee's date of retirement; or

     (d)  the  date  of  the  Employee's  Termination;   provided  that  if  the
          Employee's employment ceases because of a Termination, any exercise of
          the Option  occurring on or after the  Employee's  date of Termination
          shall be void and shall be ineffective.

         For purposes of this  Agreement,  the  Employee's  "date of retirement"
shall be the date of Retirement,  Early  Retirement or Disability  Retirement as
those terms are defined in the Plan.

         If the Employee exercises the Option with respect to a portion, but not
all, of the shares of Stock subject  thereto,  the Option shall thereafter cease
to be exercisable with respect to the shares of Stock for which it was exercised
but,  subject to the terms and conditions of the Plan and this Agreement,  shall
continue to be  exercisable  with respect to the shares of Stock with respect to
which it was not exercised.

         If the  Employee's  Termination  occurs  prior to the date on which any
portion of the Option has become  exercisable,  that portion of the Option shall
be forfeited upon such Termination.  Notwithstanding the foregoing provisions of
this Agreement,  the Option shall not become  exercisable and shall be forfeited
if the Employee does not become an employee of the Company, and the Option shall
be forfeited if the Employee  becomes an employee of the Company but voluntarily
resigns within 30 days after his initial date of employment.

                                  SECTION FOUR
                               METHOD OF EXERCISE

         Subject to the terms and conditions of the Plan and this Agreement, the
Option may be exercised,  in whole or in part,  by filing a written  notice with
the Secretary of the Company at its corporate  headquarters prior to the date on
which the Option expires or is otherwise canceled. Such notice shall specify the
date as of which  the  exercise  is to occur  and the  number of shares of Stock
which  the  Employee  elects  to  purchase  and  shall be in such form and shall
contain such other  information  as the Secretary of the Company may  reasonably
require.  The election  shall be  accompanied by payment of the option price for
such shares of Stock  indicated by the  Employee's  election,  together with the
amount of any required  state,  federal or local  withholding  taxes  arising in
connection  with the purchase of such Stock.  Subject to the  provisions  of the
preceding  sentence and the terms of the Plan, payment shall be by cash or check
payable to the Company,  by delivery of shares of Stock having an aggregate Fair
Market Value  (determined as of the date of exercise) equal to the option price,
and if elected in accordance with this Section 4, the Employee's tax withholding
obligation for the shares of Stock,  indicated by the Employee's election,  or a
combination of both.

                                  SECTION FIVE
                                 TRANSFERABILITY

         The Option shall not be transferable by the Employee other than by will
or the laws of descent and distribution and, during the life of the Employee, is
exercisable only by the Employee or Employee's guardian or legal representative.

                                   SECTION SIX
                         NOTICE OF DISPOSITION OF SHARES

         The  Employee  agrees to notify the  Company  promptly  in the event of
disposal  of any  shares of Stock  acquired  upon the  exercise  of the  Option,
including a disposal by sale, exchange, gift or transfer of legal title.

                                  SECTION SEVEN
                                 ADMINISTRATION

         The authority to manage and control the operation and administration of
this Agreement  shall be vested in the Committee,  and the Committee  shall have
all powers with respect to this  Agreement that it has with respect to the Plan.
Any  interpretation  of this Agreement by the Committee and any decision made by
it with respect to the Agreement is final and binding on all persons.

                                  SECTION EIGHT
                                  PLAN GOVERNS

         Notwithstanding  anything in this Agreement to the contrary,  the terms
of this Agreement shall be subject to the terms of the Plan, a copy of which may
be obtained by the  Employee  from the office of the  Secretary  of the Company.
Unless the context  clearly  implies or indicates the contrary,  a word, term or
phrase used or defined in the Plan is similarly  used or defined for purposes of
this Agreement.

                                  SECTION NINE
                                    AMENDMENT

         This Agreement may be amended by written  agreement of the Employee and
the  Company,  acting  pursuant to  authority  from the  Committee,  without the
consent of any other person.

                                   SECTION TEN
                   CONTINUED EMPLOYMENT, RIGHTS AS SHAREHOLDER

         This Agreement  does not constitute a contract of employment,  and does
not  give  the  Employee  the  right  to be  employed  by  the  Company  or  its
Subsidiaries.  This  Agreement  does not confer on the  Employee any rights as a
shareholder of the Company prior to the date on which the Employee  fulfills all
conditions for receipt of Stock pursuant to this Agreement and the Plan.

                                 SECTION ELEVEN
                                  GOVERNING LAW

         This Agreement  shall be construed and  administered in accordance with
the laws of the State of Illinois, without regard to the principles of conflicts
of law.


         IN WITNESS  WHEREOF,  the  parties  have caused  this  Agreement  to be
executed as of the day and year first above written.

                                                ------------------------------
                                                William B. Conway Jr.


                                                Illinova Corporation

                                                By:___________________________
                                                   Charles E. Bayless
                                                   Chairman, President and Chief
                                                   Executive Officer

ATTEST:



- ---------------------------------

                              ILLINOVA CORPORATION
                            SUPPLEMENTAL PENSION PLAN

     The Supplemental Pension Plan (the "Plan") is adopted effective as of April
12, 1999. The Plan is established and maintained by Illinova Corporation for the
purpose  of  providing  benefits  for the  Participant,  William  B.  Conway Jr.
Accordingly,  Illinova  Corporation hereby adopts the Plan pursuant to the terms
and provisions set forth below:

                                    ARTICLE I

                                   Definitions

         Wherever  used  herein the  following  terms  shall  have the  meanings
hereinafter set forth:

         1.1 "Accrued Vested Benefit" of the Participant  shall have the meaning
determined in accordance with Section 3.1.

         1.2 "Board" means the Board of Directors of the Company.

         1.3  "Cause" means:

     (a)  the  Participant's  conviction  of any  criminal  violation  involving
          dishonesty, fraud, or breach of trust,

     (b)  the  Participant's   willful  engagement  in  any  misconduct  in  the
          performance  of the  Participant's  duty that  materially  injures the
          Company,

     (c)  the  Participant's  performance  of any act  which,  if  known  to the
          shareholders or regulators of the Company or any of its  subsidiaries,
          would  materially and adversely  affect the business of the Company or
          any of its subsidiaries, or

     (d)  the Participant's  willful and substantial  nonperformance of assigned
          duties;  provided that such nonperformance has continued more than ten
          days after the Company has given written notice of such nonperformance
          and of its intention to terminate the Participant's employment because
          of such nonperformance.

     1.4 "Code" means the Internal Revenue Code of 1986, as amended from time to
time, and any regulations relating thereto.

     1.5 "Company" means Illinova Corporation,  an Illinois corporation,  or, to
the extent  provided in Section 7.8, any successor  corporation  or other entity
resulting from a merger or consolidation  into or with the Company or a transfer
or sale of substantially all of the assets of the Company.


     1.6  "Earnings"  of the  Participant  for  any  calendar  month  means  the
Participant's  accrued  salary and bonus for that month and,  for this  purpose,
shall include any portion of such salary or bonus that would otherwise have been
includible  for the month but is  contributed  by the  Company  on behalf of the
Participant  pursuant to the  Participant's  election under a "qualified cash or
deferred arrangement" (as defined in section 401(k) of the Code) that is part of
any qualified  profit  sharing plan  maintained by the Company.  For purposes of
this  definition,  the  Participant's  bonus for any  month is the bonus  amount
earned under the Executive  Incentive  Compensation Plan (or any other successor
plan providing for an annual bonus) for that month.  For each calendar year, the
annual  bonus shall be deemed to be earned  evenly  during each of the months in
which the Participant was employed by the Company during that year.

     1.7 "Final Average Earnings" means the average of the Participant's monthly
Earnings  during the 36  consecutive  calendar  months that produces the highest
average  and that  occurs  during the last 60  calendar  months  ending with the
calendar  month  in  which  the   Participant's   employment  with  the  Company
terminates.  If the Participant total employment period with the Company is less
than 36 calendar  months,  his Final  Average  Earnings  shall be  determined by
averaging  (on a calendar  month  basis) the  Earnings  received by him from the
Company during his entire period of employment.

     1.8  "Normal  Retirement  Date" means the first day of the  calendar  month
coinciding with or next following the Participant's 65th birthday.

     1.9 "Participant" means William B. Conway Jr.

     1.10 "Plan" means the Illinova Corporation Supplemental Pension Plan.

     1.11 "Qualified  Plan" means the Illinois Power Company  Retirement  Income
Plan for Salaried Employees or any successor plan.

     1.12  "Qualified  Plan  Retirement  Benefit" means the benefit payable to a
Participant  pursuant  to the  Qualified  Plan by reason of his  termination  of
employment with the Company for any reason other than death.

     1.13 "Qualified Plan Surviving Spouse Benefit" means the benefit payable to
the Surviving  Spouse of the  Participant  pursuant to the Qualified Plan in the
event of the  death of the  Participant  at any time  prior to  commencement  of
payment of his Qualified Plan Retirement Benefit.

     1.14  "Supplemental  Retirement  Benefit" means the benefit  payable to the
Participant pursuant to the Plan by reason of his termination of employment with
the Company for any reason other than death.

     1.15 "Surviving Spouse" means a person who is married to the Participant at
the date of his death and for at least one year prior thereto.

     1.16 "Supplemental Surviving Spouse Benefit" means the benefit payable to a
Surviving Spouse pursuant to the Plan.

     1.17 The  Participant's  "termination" of employment with the Company shall
be deemed to occur on the day immediately following the date on which he is last
employed by the Company.

     1.18 Words in the  masculine  gender  shall  include the  feminine  and the
singular  shall  include the plural,  and vice versa,  unless  qualified  by the
context.  Any headings used herein are included for ease of reference  only, and
are not to be construed so as to alter the terms hereof.

                                   ARTICLE II
                                   Eligibility

     The  Participant  shall be  eligible to receive a  Supplemental  Retirement
Benefit to the extent  provided in Article III of the Plan.  If the  Participant
dies prior to commencement of payment of his Qualified Plan Retirement  Benefit,
the  Surviving  Spouse  of the  Participant  shall  be  eligible  to  receive  a
Supplemental  Surviving  Spouse Benefit to the extent  provided in Article IV of
the Plan.

                                   ARTICLE III
                         Supplemental Retirement Benefit

     3.1 Amount.  The  Supplemental  Retirement  Benefit shall be payable to the
Participant  in the form of a straight  life  annuity  over the  lifetime of the
Participant only, commencing on his Normal Retirement Date, and shall consist of
a monthly  amount equal to the excess of the amount  described in paragraph  (a)
over the amount described in paragraph (b) below:

          (a)  the Participant's Accrued Vested Benefit;

           LESS

          (b) the  monthly  amount  of the  Qualified  Plan  Retirement  Benefit
     actually payable to the Participant under the Qualified Plan.

     The  amounts  described  in (a) and (b) shall be computed as of the date of
termination of employment of the  Participant  with the Company in the form of a
straight  life  annuity  payable  over  the  lifetime  of the  Participant  only
commencing on his Normal Retirement Date.

     The   Participant's   "Accrued  Vested  Benefit"  shall  be  determined  in
accordance with the following:



     (i)  if the  Participant's  employment with the Company  terminates for any
          reason prior to January 1, 2000,  his Accrued  Vested Benefit shall be
          zero, and he shall not be entitled to any benefits under the Plan;

     (ii) if the  Participant's  employment  with the Company  terminates  after
          December 31, 1999, and the  termination  occurs by reason of his being
          discharged  by the  Company  without  Cause,  or if the  Participant's
          employment with the Company  terminates on or after April 12, 2009 for
          any reason, the Participant's Accrued Vested Benefit shall be equal to
          40% of the Participant's  Final Average Earnings as of the date of his
          termination of employment; and

     (iii)if the  Participant's  employment  with the Company  terminates  after
          December  31, 1999 and prior to April 12,  2009,  and the  termination
          occurs for any reason other than his being  discharged  by the Company
          without Cause, the Participant's Accrued Vested Benefit shall be equal
          to 40% of the  Participant's  Final Average Earnings as of the date of
          his  termination of employment,  multiplied by the vesting  percentage
          determined in accordance with the following schedule:

- ----------------------------------------- --------------------------------------
If the Participant's employment with the        The vesting percentage shall be:
   Company terminates during this period:
- ----------------------------------------- --------------------------------------
  On or after April 12, 2000, and before
              April 12, 2001                               10%
- ----------------------------------------- --------------------------------------
  On or after April 12, 2001, and before
              April 12, 2002                               20%
- ----------------------------------------- --------------------------------------
  On or after April 12, 2002, and befor
              April 12, 2003                               30%
- ----------------------------------------- --------------------------------------
  On or after April 12, 2003, and before
              April 12, 2004                               40%
- ----------------------------------------- --------------------------------------
  On or after April 12, 2004, and before
              April 12, 2005                               50%
- ----------------------------------------- --------------------------------------
  On or after April 12, 2005, and before 
              April 12, 2006                               60%
- ----------------------------------------- --------------------------------------
  On or after April 12, 2006, and before
              April 12, 2007                               70%
- ----------------------------------------- --------------------------------------
  On or after April 12, 2007, and before 
              April 12, 2008                               80%
- ----------------------------------------- --------------------------------------
  On or after April 12, 2008, and before 
              April 12, 2009                               90%
- ----------------------------------------- --------------------------------------
        After April 12, 2009                              100%
- ----------------------------------------- --------------------------------------

         3.2 Form of Benefit. The Supplemental Retirement Benefit payable to the
Participant  shall be paid in the same  form  under  which  the  Qualified  Plan
Retirement  Benefit is payable to the Participant.  The  Participant's  election
under the Qualified  Plan of any optional form of payment of his Qualified  Plan
Retirement  Benefit shall also be applicable to the payment of his  Supplemental
Retirement Benefit.


         3.3  Commencement of Benefit.  Payment of the  Supplemental  Retirement
Benefit to the  Participant  shall  commence  on the same date as payment of the
Qualified Plan  Retirement  Benefit to the Participant  commences.  Any election
under  the  Qualified  Plan  made  by  the  Participant   with  respect  to  the
commencement of payment of his Qualified Plan  Retirement  Benefit shall also be
applicable  with  respect to the  commencement  of  payment of his  Supplemental
Retirement Benefit.

         3.4 Approval of Company. Notwithstanding the provisions of Sections 3.2
and 3.3 above, an election made by the Participant under the Qualified Plan with
respect to the form of payment of his Qualified Plan  Retirement  Benefit or the
date for  commencement of payment thereof shall not be effective with respect to
the form of payment  or date for  commencement  of  payment of his  Supplemental
Retirement  Benefit  hereunder  unless such  election is  expressly  approved in
writing by the Company with respect to his Supplemental  Retirement  Benefit. If
the Company shall not approve such election in writing, then the form of payment
or date for commencement of payment of the Participant's Supplemental Retirement
Benefit shall be selected by the Company in its sole discretion. If benefits are
payable to the  Participant  under this Plan, but no benefits are payable to the
Participant  under the  Qualified  Plan,  the time and form of benefit  shall be
selected by the Participant,  subject to the consent of the Company,  from among
the alternatives that would be available under the Qualified Plan (or such other
alternatives permitted by the Company).

         3.5 Actuarial  Equivalent.  A Supplemental  Retirement Benefit which is
payable in any form other than a straight  life annuity over the lifetime of the
Participant,  or which commences at any time prior to the  Participant's  Normal
Retirement  Date,  shall  be  the  actuarial   equivalent  of  the  Supplemental
Retirement  Benefit  set forth in Section  3.1 above as  determined  by the same
actuarial  adjustments as those  specified in the Qualified Plan with respect to
determination of the amount of the Qualified Plan Retirement Benefit.

                                   ARTICLE IV
                      Supplemental Surviving Spouse Benefit

         4.1 Amount. If the Participant dies either:

(i)      while employed by the Company; or

(ii)     prior to commencement of payment of his Supplemental Retirement Benefit
         under  this  Plan,  but  after  his  employment  with the  Company  has
         terminated with an Accrued Vested Benefit that is greater than zero;


          then  a  Supplemental  Surviving  Spouse  Benefit  is  payable  to his
          Surviving  Spouse as hereinafter  provided.  The monthly amount of the
          Supplemental  Surviving  Spouse Benefit payable to a Surviving  Spouse
          shall be equal to the excess of the amount  described in paragraph (a)
          over the amount described in paragraph (b) below:

(a)      the monthly amount of the Qualified  Plan  Surviving  Spouse Benefit to
         which the Surviving Spouse of the Participant  would have been entitled
         under the  Qualified  Plan,  but  determined  by applying the Surviving
         Spouse Benefit provisions of the Qualified Plan as though the amount of
         the monthly  benefit  (payable in the form of a straight  life  annuity
         commencing  at the  Participant's  Normal  Retirement  Date)  which the
         Participant  had  earned on the date of his death had been equal to the
         amount of his Accrued Vested Benefit (as defined in Section 3.1 of this
         Plan);

                                      LESS
                           (b)  the  monthly   amount  of  the  Qualified   Plan
         Surviving Spouse Benefit actually payable to the Surviving Spouse under
         the Qualified Plan.

         Notwithstanding  any other provision of the Plan, the Surviving  Spouse
shall be  entitled  to  benefits  under this  Section 4.1 only if she waives all
rights to receive the lump sum death  benefits to which she would  otherwise  be
entitled  under the  provisions of the April 12, 1999 letter to the  Participant
from  the  Company,  with  such  waiver  to be made  within  90 days  after  the
Participant's  death  in  accordance  with  the  procedures  established  by the
Company.

         4.2 Form and Commencement of Benefit.  A Supplemental  Surviving Spouse
Benefit  shall be payable  over the  lifetime  of the  Surviving  Spouse only in
monthly  installments  commencing on the date for commencement of payment of the
Qualified Plan Surviving  Spouse Benefit to the Surviving Spouse and terminating
on the date of the last payment of the Qualified Plan  Surviving  Spouse Benefit
made before the Surviving Spouse's death.

                                    ARTICLE V
                           Administration of the Plan

         5.1 Administration by the Company. The Company shall be responsible for
the general  operation and  administration  of the Plan and for carrying out the
provisions thereof.



         5.2 General Powers of  Administration.  All provisions set forth in the
Qualified  Plan with  respect  to the  administrative  powers  and duties of the
Company,  expenses of administration and procedures for filing claims shall also
be  applicable  with respect to the Plan.  The Company shall be entitled to rely
conclusively  upon all tables,  valuations,  certificates,  opinions and reports
furnished  by any  actuary,  accountant,  controller,  counsel  or other  person
employed or engaged by the Company with respect to the Plan.

                                   ARTICLE VI
                            Amendment or Termination

         The  Plan  may be  amended  or  terminated  at any  time by the  Board,
provided  however  that,  notwithstanding  any other  provision of the Plan,  no
amendment  or  termination  that  would  adversely  affect  the  rights  of  the
Participant or his Surviving Spouse (including, without limitation, his right to
accrue  future  benefits)  may be made by the  Company  except  with the written
consent of the  Participant  (or,  in the event of his death,  with the  written
consent of the Surviving Spouse).

                                   ARTICLE VII
                               General Provisions

         7.1  Funding.  The Plan at all times shall be entirely  unfunded and no
provision  shall at any time be made with respect to  segregating  any assets of
the Company for payment of any benefits  hereunder.  No  Participant,  Surviving
Spouse or any other person shall have any interest in any  particular  assets of
the  Company by reason of the right to receive a benefit  under the Plan and any
such Participant, Surviving Spouse or other person shall have only the rights of
a general unsecured creditor of the Company with respect to any rights under the
Plan.

         7.2 General Conditions.  Except as otherwise expressly provided herein,
all terms and  conditions of the Qualified  Plan  applicable to a Qualified Plan
Retirement  Benefit or a Qualified Plan  Surviving  Spouse Benefit shall also be
applicable to a  Supplemental  Retirement  Benefit or a  Supplemental  Surviving
Spouse  Benefit  payable  hereunder.  Any Qualified Plan  Retirement  Benefit or
Qualified Plan Surviving Spouse Benefit,  or any other benefit payable under the
Qualified Plan, shall be paid solely in accordance with the terms and conditions
of the Qualified  Plan and nothing in this Plan shall operate or be construed in
any way to modify,  amend or affect the terms and  provisions  of the  Qualified
Plan.

         7.3 No  Guaranty  of  Benefits.  Nothing  contained  in the Plan  shall
constitute  a guaranty  by the  Company or any other  entity or person  that the
assets of the Company will be sufficient to pay any benefit hereunder.

         7.4 No  Enlargement  of Employee  Rights.  No  Participant or Surviving
Spouse  shall have any right to a benefit  under the Plan  except in  accordance
with the terms of the Plan.  Establishment of the Plan shall not be construed to
give any Participant the right to be retained in the service of the Company.



         7.5 Spendthrift  Provision.  No interest of any person or entity in, or
right to  receive a benefit  under,  the Plan  shall be subject in any manner to
sale, transfer, assignment, pledge, attachment, garnishment, or other alienation
or  encumbrance of any kind; nor may such interest or right to receive a benefit
be taken, either voluntarily or involuntarily, for the satisfaction of the debts
of, or other  obligations or claims  against,  such person or entity,  including
claims for  alimony,  support,  separate  maintenance  and claims in  bankruptcy
proceedings.

         7.6 Applicable Law. The Plan shall be construed and administered  under
the laws of the State of Illinois.
                  
         7.7  Incapacity  of  Recipient.  If any  person  entitled  to a benefit
payment  under the Plan is deemed by the Company to be incapable  of  personally
receiving and giving a valid receipt for such  payment,  then,  unless and until
claim therefor shall have been made by a duly appointed  guardian or other legal
representative  of such person,  the Company may provide for such payment or any
part thereof to be made to any other  person or  institution  then  contributing
toward  or  providing  for the care and  maintenance  of such  person.  Any such
payment  shall be a  payment  for the  account  of such  person  and a  complete
discharge of any liability of the Company and the Plan therefor.

         7.8 Corporate Successors.  The Plan shall be binding upon, and inure to
the benefit of, the Company and its  successors  and assigns and upon any person
acquiring,  whether by merger,  consolidation,  purchase of assets or otherwise,
all or substantially all of the Company's assets and business, and the successor
shall be substituted for the Company under the Plan.

         7.9 Unclaimed Benefit.  The Participant shall keep the Company informed
of his current address and the current address of his spouse.  The Company shall
not be obligated to search for the whereabouts of any person. If the location of
the  Participant  is not made known to the Company  within three (3) years after
the date on which payment of the Participant's  Supplemental  Retirement Benefit
may first be made, payment may be made as though the Participant had died at the
end of the  three-year  period.  If,  within  one  additional  year  after  such
three-year period has elapsed,  or, within three years after the actual death of
the  Participant,  the Company is unable to locate any  Surviving  Spouse of the
Participant,  then the  Company  shall  have no  further  obligation  to pay any
benefit  hereunder to such  Participant or Surviving  Spouse or any other person
and such benefit shall be irrevocably forfeited.

         7.10  Limitations  on Liability.  Notwithstanding  any of the preceding
provisions  of the Plan,  neither the Company  nor any  individual  acting as an
employee  or agent of the  Company  shall be liable to any  Participant,  former
Participant, Surviving Spouse or any other person for any claim, loss, liability
or expense incurred in connection with the Plan.



         IN WITNESS  WHEREOF,  the  undersigned,  on behalf of the Company,  has
executed this Plan to witness its adoption by the Company April _____, 1999, and
the  Participant  has executed  this Plan to witness his  understanding  that it
reflects his agreement with the Company.

                                                     ILLINOVA CORPORATION


                                                     By:________________________

Accepted and agreed to this
 ____ day of April, 1999.




      William B. Conway Jr.




                              ILLINOVA CORPORATION
                          EMPLOYEE RETENTION AGREEMENT

     THIS EMPLOYEE  RETENTION  AGREEMENT (the  "Agreement")  is entered into the
12th  day of  April,  1999 by and  between  ILLINOVA  CORPORATION,  an  Illinois
corporation (the "Company") and William B. Conway Jr. (the "Employee").
         
     WHEREAS,  the  Company  desires  to retain  the  services  of  Employee  in
connection with any change in control of the Company;

     NOW, THEREFORE, in consideration of continued employment and for other good
and  valuable  consideration,  the receipt and  sufficiency  of which are hereby
acknowledged, the Company and the Employee agree as follows:
         
     1. Change in Control Benefits.  The provisions of paragraphs (a), (b), (c),
(d) and (e) below shall apply if a Termination Event occurs:

(a)  The Employee shall be entitled to receive from the Company,  within 30 days
     of the Termination Event or, in the case of a Termination Event that occurs
     under paragraph  2(a)(iv)(C)  (relating to termination prior to a Change in
     Control at the request of an acquiror), within 30 days following the Change
     in Control,  a lump sum cash  payment  equal to three times the sum of: (I)
     the greater of the  Employee's  annual salary rate in effect on the date of
     the Change in Control,  or the  Employee's  annual salary rate in effect on


     the date Employee's  employment with the Company terminates;  plus (II) the
     amount of the latest  annual bonus earned by  Employee,  provided  that the
     amount  described in this  paragraph (II) shall be zero unless the Employee
     has  received an annual  bonus in one or more of the three  calendar  years
     last preceding the termination.

(b)  Notwithstanding  any provision in the promissory  note or the tax letter to
     the contrary,  any  obligation of the Employee for payment of principal and
     interest otherwise due under the promissory note shall be forgiven, and the
     Employee shall be entitled to the tax gross-up  payment as described in the
     tax letter with respect to such forgiven  interest (but not with respect to
     the  forgiven  principal).  For  purposes of this  paragraph  (b), the term
     "promissory  note" shall mean the promissory note dated April 12, 1999 with
     respect to the borrowing of $250,000 by the Employee from the Company,  and
     the term  "tax  letter"  shall  mean the  letter  from the  Company  to the
     Employee  dated April 12, 1999  providing for the tax gross-up with respect
     to the forgiveness of interest under the promissory note.

(c)  Notwithstanding  any  provision  in the  Supplemental  Pension  Plan to the
     contrary,  the Employee's  Accrued  Vested  Benefit under the  Supplemental
     Pension Plan shall be equal to 40% of the Employee's Final Average Earnings
     (as  defined  under the  Supplemental  Pension  Plan) as of the date of his
     termination of employment with the Company.

(d)  The Employee and his dependents,  if any, shall, for thirty-six (36) months
     following the  Employee's  termination  of employment or until the Employee
     reaches  65 years of age or is  employed  by another  employer,  if sooner,
     continue to  participate in any benefit plans for the Company which provide
     


     health (including  medical and dental),  life or disability  insurance,  or
     similar coverage;  provided,  however, that if the Employee has attained 50
     years of age prior to his date of termination, the Employee and dependents,
     if any,  shall be  eligible  to  participate  in any  benefit  plans of the
     Company which provide health and life insurance or similar  coverage as are
     then extended to employees of the Company  electing early retirement at age
     55 on the same terms and subject to the same  conditions as are  applicable
     to such  employees;  provided that such coverage  shall not be furnished if
     the  Employee  waives  coverage by giving  written  notice of waiver to the
     Company.

(e)  Notwithstanding  any provision of the applicable  stock option agreement to
     the contrary,  any stock option or portion  thereof that is  exercisable on
     the  date  of the  Employee's  Termination  (as  that  term  is used in the
     applicable  stock option  agreement)  shall not be forfeited on the date of
     Termination,  but shall instead  remain  exercisable  for the 30-day period
     following the Termination (or, if greater,  the period otherwise  specified
     by the applicable option agreement);  provided that, in no event shall such
     the  option  be  exercisable  after  the date on  which  the  option  would
     otherwise  expire  if the  Employee  had  continued  in the  employ  of the
     Company.

The  Employee  shall not be  required  to  mitigate  damages  by  seeking  other
employment or otherwise.  Except as specifically provided above with the respect
to the  Employee's  becoming  an  employee of another  employer,  the  Company's
obligations  under this paragraph 1 shall not be reduced in any way by reason of
any  compensation  received by the Employee  from sources other than the Company
after termination of the Employee's employment with the Company.



     The benefits under this paragraph 1 shall be in lieu of, and not inaddition
to, any benefits to which the  Employee  might  otherwise be entitled  under any
other  severance  plan  maintained  by  the  Company  providing   benefits  upon
involuntary termination of employment.

     If a  Termination  Event occurs under  paragraph  2(a)(iv)(C)  (relating to
termination  prior to a Change in Control at the request of an  acquiror),  then
the Employee's  entitlement to compensation  and benefits under this paragraph 1
shall be  determined  as though:  (i) the  Employee  is  rehired by the  Company
immediately  prior to the  Change in  Control  at the  salary  rate equal to his
highest  salary rate during the one-year  period prior to the date of the Change
in  Control;   (ii)  his  employment  with  the  Company  is  terminated   under
circumstances described in paragraph 2(a)(iv)(A) (relating to termination by the
Company without Good Cause)  immediately  after the Change in Control;  (iii) he
had retained any options and other benefits that were forfeited by reason of his
termination  prior to the Change in Control;  and (iv) this Agreement is in full
force and  effect at the time of the Change in  Control,  and at the time of his
deemed termination of employment.

     If the  Employee  is  employed  by the  Company  on the date of a Change in
Control  then,  with respect to any stock option  granted to the Employee by the
Company  prior to the Change in Control that is  outstanding  on the date of the
Change in Control,  that option shall vest and be  exercisable  on and after the
date of the Change in Control.  Except as  otherwise  provided in the  preceding
sentence  with respect to  exercisability  of options,  the options shall remain
subject to the expiration provisions and other terms of the option awards



without regard to the preceding  sentence;  and the preceding sentence shall not
apply to any stock  option to the extent  that the terms  governing  such option
expressly  reference this Agreement and expressly provide that the provisions of
such sentence are inapplicable.

     2. Definitions. 

     (a) For purposes of this Agreement:

          (i) "Good Cause" shall mean:

               (A) the Employee's conviction of any criminal violation involving
               dishonesty, fraud, or breach of trust,

               (B) the  Employee's  willful  engagement in any misconduct in the
               performance of the Employee's  duty that  materially  injures the
               Company,

               (C) the Employee's  performance of any act which, if known to the
               shareholders   or  regulators  of  the  Company  or  any  of  its
               subsidiaries,  would materially and adversely affect the business
               of the Company or any of its subsidiaries, or

               (D) the  Employee's  willful and  substantial  nonperformance  of
               assigned duties;  provided that such nonperformance has continued
               more than ten days after the Company has given written  notice of
               such  nonperformance  and  of  its  intention  to  terminate  the
               Employee's employment because of such nonperformance.


         (ii)   "Good  Reason"  shall exist if,  without an  Employee's  express
                written consent, the Company shall:

               (A) reduce the salary of the Employee; or


               (B)  materially  reduce the amount of paid vacations to which the
               Employee is  entitled,  or the  Employee's  fringe  benefits  and
               perquisites; or

               (C) significantly  change the nature or decrease the scope of the
               Employee's authority; or

               (D) change by 50 miles or more the  principal  location  in which
               the Employee is required to perform services.


         (iii)  "Change in Control"  shall be deemed to occur on the earliest of
         the  existence of one of the following and the receipt of all necessary
         regulatory approvals therefor:

                (A) The acquisition other than from the Company,  by any entity,
                person or group  (including all Affiliates or Associates of such
                entity, person or group) of beneficial  ownership,  as that term
                is defined in Rule 13d-3 under the  Securities  Exchange  Act of
                1934,  of more than 20% of the  outstanding  shares  of  capital
                stock of the Company  entitled to vote generally in the election
                of   directors,   but   excluding  for  this  purpose  any  such
                acquisition  by the  Company or any of its  subsidiaries  or any
                employee  benefit plan (or related  trust) of the Company or its
                subsidiaries,   or  any  corporation   with  respect  to  which,
                following such acquisition, more than 80% of, respectively,  the
                then outstanding  shares of common stock of such corporation and
                the  combined  voting  power  of  the  then  outstanding  voting
                securities of such corporation entitled to vote generally in the
                election of directors is then  beneficially  owned,  directly or
                indirectly,  by all or substantially  all of the individuals and
                entities who were the beneficial  owners,  respectively,  of the
                common stock and voting  securities  of the Company  immediately
                


                prior to such acquisition in  substantially  the same proportion
                as their ownership,  immediately prior to such  acquisition,  of
                the then  outstanding  shares of common  stock of the Company or
                the  combined  voting  power  of  the  then  outstanding  voting
                securities  of the  Company  entitled to vote  generally  in the
                election  of  directors,  as the case may be; 

               (B)  The   effective   time  of  a   reorganization,   merger  or
               consolidation of the Company, in each case, with respect to which
               all or substantially all of the individuals and entities who were
               the respective  beneficial  owners of the common stock and voting
               securities   of   the   Company   immediately   prior   to   such
               reorganization,  merger or consolidation  do not,  following such
               reorganization,   merger,  or  consolidation   beneficially  own,
               directly and indirectly more than 80% of  respectively,  the then
               outstanding  shares of common stock or the combined  voting power
               of the  then  outstanding  voting  securities  entitled  to  vote
               generally  in the election of  directors,  as the case may be, of
               the  corporation  resulting from such  reorganization,  merger or
               consolidation, or of a complete liquidation or dissolution of the
               Company  or of the sale or  other  disposition  of a  Substantial
               Portion of the Property of the Company; or

               (C) The  election  to the Board of  Directors  of the  Company of
               directors  constituting a majority of the number of the directors
               in office unless such directors were  recommended for election by
               the existing Board of Directors.



               (iv) A  "Termination  Event"  means the date that the  Employee's
               employment with the Company terminates under one of the following
               circumstances:

               (A)  The  Employee's  employment  is  terminated  by the  Company
               without  Good Cause  within two (2) years  following  a Change in
               Control.

               (B) The  Employee  voluntarily  terminates  employment  with Good
               Reason within two (2) years following a Change in Control.

               (C) The Employee's  employment is terminated prior to a Change in
               Control  at the  request  of an  acquiror.  For  purposes  of the
               definition of Termination Event, a termination will not be deemed
               to have occurred  solely  because of the transfer of the Employee
               between the Company and a subsidiary  of the Company,  or between
               two subsidiaries of the Company.

     (b)  For purposes of the foregoing,  (i)  "Affiliate" or "Associate"  shall
          have the meaning set forth in Rule 12b-2 under the Securities Exchange
          Act of 1934,  and (ii)  "Substantial  Portion of the  Property  of the
          Company"  shall mean 80% of the aggregate  book value of the assets of
          the Company and its Affiliates and Associates as set forth on the most
          recent balance sheet of the Company, prepared on a consolidated basis,
          by its regularly employed, independent, certified public accountant.

     (c)  Notwithstanding the foregoing, a Change in Control shall not be deemed
         to occur for the Employee by virtue of any transaction in which such an
         Employee is a  participant  in a group  effecting an  acquisition  that
         constitutes  a Change  in  Control  if,  after  such  acquisition,  the
         Employee  holds an  equity  interest  in the  entity  that has made the
         acquisition.  


     3.  Litigation  Expenses.  The  Company  shall  pay  to  the  Employee  the
attorneys'  fees incurred by the Employee in connection  with any claim or legal
action or proceeding  involving this Agreement,  whether brought by the Employee
or by or on behalf of the Employee or by another party;  provided,  however, the
Company  shall not be obligated to pay to the Employee  out-of-pocket  expenses,
including attorneys' fees, incurred by the Employee in any claim or legal action
or  proceeding  in which the  Employee is a party  adverse to the Company if the
Company prevails in such litigation.  The Company shall pay prejudgment interest
on any money  judgment  obtained by the  Employee,  calculated  at the published
prime interest rate charged by the Company's principal banking connection, as in
effect from time to time,  from the date that  payment(s) to the Employee should
have been made under this Agreement.
        
     4. Post-termination  Payment Obligations Absolute. The Company's obligation
to pay the Employee the amounts and to make the other arrangements  provided for
herein to be paid and made after  termination of the Employee's  employment with
the Company shall be absolute and unconditional and shall not be affected by any
circumstances,   including,  without  limitation,  any  set-off,   counterclaim,
recoupment,  defense  or other  right  that the  Company  may have  against  the
Employee  or anyone  else.  The Company  hereby  waives any  contract  formation
defenses  that it may have with  respect to the Employee  Retention  program and
this Agreement.


     5.  Withholding.  The  Company  may  withhold  from  any  payment  that  it
isrequired to make under this Agreement amounts sufficient to satisfy applicable
withholding requirements under any federal, state, or local law

     6.  Successors.  The  obligations  of the  Company  provided  for  in  this
Agreement shall be the binding legal obligations of any successor to the Company
by purchase, merger,  consolidation,  or otherwise.  Rights under this Agreement
may not be assigned by the Employee  during the  Employee's  life,  and upon the
Employee's death will inure to the benefit of the Employee's heirs, legatees and
the legal representatives of the Employee's estate.

     7.   Interpretation.   The  validity,   interpretation,   construction  and
performance  of this  Agreement  shall be  governed  by the laws of the State of
Illinois.  The invalidity or unenforceability of any provision of this Agreement
shall not affect the validity or enforceability of any other provision.

     8. Amendment. This Agreement may be amended or cancelled only by the mutual
agreement of the parties in writing without the consent of any other person.  So
long as the Employee lives, no person, other than the parties hereto, shall have
any rights under or interest in this Agreement or the subject matter hereof.

     9. Tax Payments.  This paragraph 9 shall apply if all or any portion of the
payments and  benefits  provided to the Employee  under this  Agreement,  or any
benefit (including any plan adopted in the future),  would otherwise  constitute
"excess  parachute  payments" within the meaning of Section 280G of the Internal
Revenue  Code of 1986,  as amended  (the  "Code"),  that are  subject to the tax
imposed by Section  4999 of the Code (or  similar  tax and/or  assessment).  If,




after the application of such tax and/or assessment,  the amount of such payment
and benefits  would be less than if the payment and benefits had been reduced to
an amount that would result in there being no excess  parachute  payments,  then
such payments and benefits shall be so reduced (the minimum extent  necessary so
that no excess parachute payments result). If reduction is necessary  hereunder,
the Employee  shall elect which of the  payments and benefits  shall be reduced.
Determination of whether payments and benefits would constitute excess parachute
payments, and the amount of reduction so that no excess parachute payments shall
exist,  shall be made, at the Company's expense,  by the independent  accounting
firm employed by the Company  immediately  prior to the occurrence of any change
of control of the Company which will result in the imposition of such tax.



         IN WITNESS  WHEREOF,  the Company and the Employee  have  executed this
Agreement on the ____ day of April, 1999. This Agreement supersedes and replaces
any prior  agreement  between the Company and the  undersigned,  regarding  this
subject.
                                               ILLINOVA CORPORATION



             By:______________________________________




             -----------------------------------------
                       WILLIAM B. CONWAY JR.

                                 PROMISSORY NOTE

$250,000.00  April 12, 1999
                                                               Decatur, Illinois

         FOR  VALUE  RECEIVED,  the  undersigned,  William  B.  Conway  Jr.,  an
individual  (the  "Employee"),   promises  to  pay  to  the  order  of  Illinova
Corporation,  an Illinois corporation (the "Company"),  on the date on which the
Employee's  employment with the Company  terminates (the "Maturity  Date"),  the
principal sum of $250,000.00 and any accrued  interest on this Note,  subject to
the provisions of this Note relating to forgiveness of such obligations.

         This Note evidences  obligations in connection  with a loan made by the
Company to the  Employee  as part of the  inducement  to the  Employee to become
employed by the Company.

         The unpaid  principal amount of this Note from time to time outstanding
shall bear interest at a rate per annum (based upon a 365/366 day year) equal to
the applicable  Federal rate as of April 12, 1999, as determined for purposes of
section  1274(d) of the Internal  Revenue Code of 1986,  as amended,  compounded
annually.  After the Maturity Date, any unpaid and unforgiven  principal  amount
and  accrued  unforgiven  interest on the unpaid  principal  amount of this Note
shall be payable on demand.

         As of each of the first five one-year  anniversaries of April 12, 1999,
if the Employee is employed by the Company on such anniversary,  an amount equal
to  $50,000.00 of the  principal  amount due under this Note,  together with the
amount of interest that has accrued with respect to the entire unpaid  principal
and interest  amount  since the  preceding  April 12 shall be  forgiven.  If the
Employee's  employment with the Company  terminates prior to April 12, 2004, and
such  termination  is the result of being  discharged by the Company for reasons
other than Cause, any remaining principal and interest shall be forgiven. If the
Employee's employment with the Company terminates (i) prior to April 12, 2004 by
the  Company  for  Cause,  or (ii)  prior to April  12,  2004 by  reason  of the
Employee's  death,  disability,  or voluntary  resignation,  then any  remaining
principal  and  interest  shall  become  due  and  payable  on the  date of such
termination  of  employment.  For purposes of this Note,  the term "Cause" shall
mean:

     (a)  the  Employee's   conviction  of  any  criminal  violation   involving
          dishonesty, fraud, or breach of trust,

     (b)  the Employee's willful engagement in any misconduct in the performance
         of the Employee's duty that materially injures the Company,


     (c)  the  Employee's  performance  of  any  act  which,  if  known  to  the
          shareholders or regulators of the Company or any of its  subsidiaries,
          would  materially and adversely  affect the business of the Company or
          any of its subsidiaries, or

     (d)  the  Employee's  willful and  substantial  nonperformance  of assigned
          duties;  provided that such nonperformance has continued more than ten
          days after the Company has given written notice of such nonperformance
          and of its intention to terminate the Employee's employment because of
          such nonperformance.

         Subject to the other terms and  conditions  hereof,  the  Employee  may
voluntarily  prepay all or any  portion of the unpaid and  unforgiven  principal
amount of this Note from time to time outstanding and any accrued and unforgiven
interest thereon, without premium or penalty.

         All payments of principal of and interest on this Note shall be payable
in lawful currency of the United States of America at Decatur,  Illinois or such
other place as the Company shall  designate to the Employee in writing,  in cash
or by check. If payment hereunder falls due on a day which is either a Saturday,
Sunday or any other day on which banks in Decatur,  Illinois  are not  generally
open for business to the public (i.e., not a "Business Day"), then such due date
shall be extended to the  immediately  succeeding  Business Day, and  additional
interest shall accrue and be payable for the period of any such extension.

         The  Employee  agrees  that if any of the  following  events of default
(each an "Event of Default") shall occur and be continuing:

     (i)  default in the  performance  or observance of any other  agreements of
          the Employee contained herein, or

     (ii) the institution of any bankruptcy, insolvency, receivership or similar
          proceeding relating to the Employee or his assets, and if such case or
          proceeding  is not  commenced by the  Employee,  it is consented to or
          acquiesced in by the Employee or remains for 60 days undismissed;

then the Company may declare this Note and all unpaid and  unforgiven  principal
of and interest on this Note and all accrued  costs,  expenses and other amounts
under this Note to be due and  payable,  whereupon  all  unpaid  and  unforgiven
principal  of and  interest on this Note and all such costs,  expenses and other
amounts shall immediately become due and payable following such declaration.

         The Employee  hereby  represents  and warrants to the Company as of the
date hereof (i) that this Note is the legally  valid and binding  obligation  of
the Employee, enforceable against the Employee in accordance with its terms, and
(ii) that the execution,  delivery and  performance by the Employee of this Note
does not conflict  with or contravene  (a) any law,  rule or regulation  binding



upon the Employee or affecting any of the Employee's  assets,  (b) any provision
of any contract,  instrument or agreement binding upon the Employee or affecting
any of the  Employee's  assets,  or (c) any  writ,  order,  judgment,  decree or
decision of any court or governmental  instrumentality binding upon the Employee
or affecting any of the Employee's assets.

         All  notices,   certificates  and  other   communications   ("Notices")
hereunder  shall  be in  writing  and may be  either  delivered  personally,  by
nationally  recognized express courier for overnight  delivery,  or by facsimile
(with request for assurance of receipt in a manner  appropriate  with respect to
communications  of that type,  provided that a confirmation copy is concurrently
sent by a  nationally  recognized  express  courier for  overnight  delivery) or
mailed,  postage  prepaid,  by  certified or  registered  mail,  return  receipt
requested, addressed as follows:

         If to the Company:                 Illinova Corporation
                                            500 South 27th Street
                                            Decatur, Illinois  62521
                                            Attention: General Counsel

         If to the Employee:                William B. Conway Jr.
                                            Illinova Corporation
                                            500 South 27th Street
                                            Decatur, Illinois  62521

         All notices hereunder shall be sent to the Employee or the Company,  as
appropriate,  at such party's  address shown above,  or at such other address as
such party may,  by written  notice  received by the other  party  hereto,  have
designated  as its or his address for such  purpose.  Notices  sent by facsimile
transmission  shall be deemed to have been given when sent; notices sent by mail
shall be deemed to have been given five days after the date mailed by registered
or certified mail,  postage prepaid;  and notices sent by hand delivery shall be
deemed to have been given when received.

         This Note has been made and delivered at Decatur, Illinois and shall be
construed in  accordance  with and governed by the internal laws of the State of
Illinois. Wherever possible, each provision of this Note shall be interpreted in
such  manner as to be  effective  and valid  under  applicable  law,  but if any
provision of this Note shall be prohibited by or invalid under  applicable  law,
such provision  shall be ineffective to the least extent of such  prohibition or
invalidity,  without  invalidating  the  remainder  of  such  provision  or  the
remaining provisions of this Note.

         IN WITNESS WHEREOF, the Employee has caused this Note to be executed as
of the day and year first above written.

                            -----------------------------
                              William B. Conway Jr.


                                                           April 12, 1999


William B. Conway Jr.
Illinova Corporation
500 South 27th Street
Decatur, Illinois  62521

Dear Mr. Conway:

         This  letter  is  to  confirm  our  verbal   agreement   that  Illinova
Corporation (the "Company") will loan you $250,000.00. The Company is making the
loan to compensate you for amounts you have foregone by leaving Troutman Sanders
LLP to join the Company. As a condition of receiving the loan, you must sign and
return one copy of this letter and the enclosed promissory note.

         As indicated in the promissory note, 20% of the principal amount of the
loan will be forgiven on each of the first through fifth  anniversaries of April
12, 1999,  if you are employed by the Company on such  anniversary.  Also, as of
each such anniversary,  the entire amount of interest accrued on the outstanding
principal during the prior one-year period shall be forgiven.

         As of each  anniversary,  the amount of the forgiveness of principal or
interest  on that date will be taxable  income to you.  As of each date on which
the forgiveness  occurs, you will become entitled to a tax gross-up payment from
the Company in an amount equal to the aggregate of the additional Federal, state
and local  income  taxes  payable  by you by reason  of the  forgiveness  of the
interest amount (but not by reason of the forgiveness of the principal  amount),
and by reason of your receipt of the gross-up payment.

         If, prior to April 12,  2004,  your  employment  is  terminated  by the
Company for  reasons  other than Cause (as  defined in the  attached  promissory
note),  the amount of any outstanding  balance of principal and interest will be
forgiven,  and you will become  entitled to a tax gross-up  payment in an amount
equal to the aggregate of the additional  Federal,  state and local income taxes
payable by you by reason of the  forgiveness of the interest  amount (but not by
reason  of the  forgiveness  of the  principal  amount),  and by  reason of your
receipt of the gross-up payment.  However,  if your employment is terminated (i)
prior to April 12,  2004 by the  Company  for Cause,  or (ii) prior to April 12,
2004 by reason of your death,  disability,  or voluntary  resignation,  then the
amount  of any  outstanding  balance  of  principal  and  interest  will  become
immediately due and payable.  After  termination of your employment,  if amounts
are due from you to repay the loan, and such amounts are otherwise  unpaid,  the
Company retains the right to offset such liability against amounts otherwise due
to you from the Company.


         If the  foregoing  reflects  your  understanding  of the  terms of your
agreement  with the Company,  please so indicate by signing and returning a copy
of this  letter  to the  undersigned,  along  with a signed  copy of each of the
enclosures.
                                                           Very truly yours,

                                                           Illinova Corporation

                                                           By:
Charles E. Bayless

Accepted and agreed to this
____ day of April, 1999.


     William B. Conway Jr.