<PAGE>   1
                                                                     EXHIBIT 4.1

                          CONSENT ACTION OF CONOCO INC.

         The undersigned, President and Chief Executive Officer of Conoco Inc.,
pursuant to a delegation from the Board of Directors of Conoco Inc., effective
August 12, 1989; subsequent delegations pursuant to corporate Authority
limitations and Governance guidelines issued on June 1, 1994, February 10, 1997,
October 30, 1997 and April 21, 1999; and pursuant to Article XIX. of the Thrift
Plan for Employees of Conoco Inc. and Article XIX. of the Thrift Plan for Retail
Employees of Conoco Inc., consents to the following actions:

         RESOLVED, That effective January 1, 2000, Article V. A. and B. of
Chapter 1 of the Thrift Plan for Employees of Conoco Inc. shall be amended to
read as follows:

         V.       CONOCO CONTRIBUTIONS

                  A.       Amount of Company Contributions

                           1.       Company shall contribute out of its
                                    accumulated earnings and profits to a
                                    Participant's Regular Account an amount
                                    equal to 100 percent of each Participant's
                                    Basic Deposits, except as hereinafter
                                    provided in Article VI. Such contributions
                                    shall be paid to the Trustee at least
                                    monthly.

                           2.       Starting in the month in which Conoco makes
                                    its first contribution pursuant to Article
                                    V.B. of the Plan, as amended effective
                                    January 1, 2000, Conoco shall make a monthly
                                    contribution to the Trustee of 1 percent of
                                    the monthly compensation in the month
                                    preceding the month in which such
                                    contribution is made of all Employees
                                    eligible to participate in the Plan in the
                                    month preceding the month in which the
                                    contribution is made, except as hereinafter
                                    provided in Article VI. Each Employee who is
                                    eligible to participate in the Plan in the
                                    month preceding the month in which the
                                    contribution is made to the Trustee shall be
                                    allocated an amount which is 1 percent of
                                    his monthly Compensation in the month
                                    preceding the month in which the
                                    contribution is made to the Trustee. Such
                                    contributions shall be allocated by the
                                    Trustee in the month following the month in
                                    which the contribution is made to the
                                    Trustee among the Regular Employee Accounts
                                    of all Employees eligible to participate in
                                    the Plan in the month preceding the month in
                                    which the contribution is made to the
                                    Trustee. After allocation by the Trustee,
                                    such contributions shall be invested as
                                    provided in Article VII.A.

                                      1
<PAGE>   2

                  B.       Additional Conoco Contributions

                           This is a profit sharing plan. Conoco may from time
                           to time voluntarily make additional contributions
                           subject to the following provisions, conditions, and
                           limitations:

                           1.       No such additional contribution shall be
                                    made unless the same is specifically
                                    authorized by the Board or its delegee.

                           2.       No such additional contribution shall be
                                    applicable to the employees of any
                                    Affiliated Company participating in the Plan
                                    unless such applicability to such employees
                                    is authorized by the board of directors of
                                    such Affiliated Company.

                           3.       Such additional contribution shall be a
                                    percentage of the monthly Compensation in
                                    the month preceding the month in which such
                                    contribution is made of all Employees
                                    eligible to participate in the Plan in the
                                    month preceding the month in which the
                                    contribution is made to the Trustee and
                                    shall be paid monthly to the Trustee. The
                                    Trustee shall allocate the contribution in
                                    the month following the month in which the
                                    contribution is made to the Trustee among
                                    the Regular Employee Accounts of all
                                    Employees eligible to participate in the
                                    Plan in the month preceding the month in
                                    which such contribution is made to the
                                    Trustee. Each Employee who is eligible to
                                    participate in the Plan in the month
                                    preceding the month in which the
                                    contribution is made to the Trustee shall be
                                    allocated an amount which is a percentage of
                                    his monthly Compensation in the month
                                    preceding the month in which such
                                    contribution is made. Such percentage shall
                                    be the same proportion that the Company
                                    contribution under this Article V.B. bears
                                    to the monthly Compensation of all Employees
                                    eligible to participate in the Plan in the
                                    month preceding the month in which the
                                    contribution is made to the Trustee. After
                                    allocation by the Trustee, such
                                    contributions shall be invested as provided
                                    in Article VII.A.

                           4.       Monthly contributions under Article V.A.2.
                                    and V.B.3. shall not exceed 6 percent of the
                                    monthly Compensation of all Employees
                                    eligible to participate in the Plan in the
                                    month preceding the month in which such
                                    contributions are made to the Trustee.

                                      2
<PAGE>   3

         FURTHER RESOLVED, That effective January 1, 2000, the first sentence of
Article VII.A. of Chapter 1 of the Thrift Plan for Employees of Conoco Inc.
shall be amended to read as follows:

         A.       Investment Direction

                  A Participant in the Plan shall instruct the Trustee in the
                  form prescribed by the Benefit Board as to the Investment
                  Direction for future deposits, contributions and income to his
                  Employee Account, except that Company contributions made
                  pursuant to Article V.A.2. or Article V.B. shall be invested
                  by the Trustee in the Conoco Stock Fund: Class B Common Stock.

         FURTHER RESOLVED, That Effective January 1, 2000, the first sentence of
the third paragraph of Article VIII.A.2. shall be amended to read as follows:

         Brokerage commissions, transfer taxes, and other charges and expenses
         in connection with the purchase or sale of securities shall be added to
         the cost of such securities or deducted from the proceeds thereof, as
         the case may be. Notwithstanding the preceding sentence, brokerage
         commissions, transfer taxes, and other charges and expenses in
         connection with the purchase of shares of the Conoco Stock Fund: Class
         B Common Stock purchased with Company contributions made pursuant to
         Article V.A.2. or B.3. shall not be added to the cost of such
         securities.

         FURTHER RESOLVED, That effective January 1, 2000, Article XIV.H.(a) of
Chapter 1 of the Thrift Plan for Employees of Conoco Inc. shall be amended to
read as follows:

         Brokerage fees, transfer taxes, investment fees, wrap fees, rebalancing
         fees and other expenses incident to the purchase, sale and operation of
         securities and other investments and incident to the administration of
         Options A, B, C and D shall be included in the cost of such securities
         or investments or deducted from the sale proceeds, as the case may be.
         Notwithstanding the preceding sentence, brokerage commissions, transfer
         taxes, and other charges and expenses in connection with the purchase
         of shares of Conoco Stock Fund: Class B Common Stock purchased with
         Company contributions made pursuant to Article V.A.2. or B.3 shall not
         be added to the cost of such securities.

         FURTHER RESOLVED, That effective January 1, 1997, Article X.E.1. and 2.
of Chapter 1 of the Thrift Plan for Employees of Conoco Inc. shall be amended to
read as follows:

         E.       Compliance with Minimum Distribution Rules

                  1.       General Rule

                           Notwithstanding any other provision of this Plan,
                           beginning January 1, 1985, a Member, Beneficiary
                           Member, Terminated Member, Retired Member, or
                           Alternate Payee shall receive

                                       3
<PAGE>   4

                           Minimum Distributions. "Minimum Distributions" shall
                           mean distributions in such amounts as are required to
                           satisfy section 401(a)(9) of the Code, the incidental
                           death benefit rule of section 401(a)(9)(G) of the
                           Code, and regulations under both of those Code
                           sections, and which are made no later than required
                           to satisfy section 401(a)(9) of the Code and
                           regulations thereunder. Except as provided in Article
                           X.E.2., 3. and 4. below, a Member, Beneficiary
                           Member, Terminated Member, Retired Member, or
                           Alternate Payee shall receive his Minimum
                           Distributions on or before his Required Beginning
                           Date in the form of a lump sum payment of his entire
                           Vested Account.

                           In the case of a Member, Terminated Member, or
                           Retired Member, who reaches age 70 1/2 prior to the
                           year 2000, or a 5 percent owner of the Company, the
                           Required Beginning Date is April 1 of the year
                           following the year in which such individual turned
                           age 70 1/2.

                           In the case of a Member, Terminated Member, or
                           Retired Member, who reaches age 70 1/2 on or after
                           January 1, 2000, the Required Beginning Date is April
                           1 of the calendar year following the later of the
                           calendar year in which the individual reaches age 70
                           1/2 or the calendar year in which the individual
                           ceases to be employed by the Corporate Employer.

                           In the case of a Beneficiary Member or Alternate
                           Payee, the Required Beginning Date is December 31 of
                           the year in which the Member to whom the benefit
                           relates turns or would have turned age 70 1/2, if
                           such Member turns or would have turned age 70 1/2
                           prior to the year 2000.

                           In the case of a Beneficiary Member or Alternate
                           Payee, the Required Beginning Date is December 31 of
                           the later of the calendar year in which the Member to
                           whom the benefit relates turns 70 1/2, would have
                           turned age 70 1/2, or ceases to be employed by the
                           Corporate Employer, if such Member turned or would
                           have turned age 70 1/2 on or after January 1, 2000.

                  2.       Active Employee

                           If a Member, who attains age 70 1/2 before January 1,
                           2000, has not terminated employment with Conoco on
                           April 1 of the calendar year following the calendar
                           year in which he attained age 70 1/2, his Minimum
                           Distribution will begin no later than that date in
                           the form of a Lifetime Periodic Payment.

         FURTHER RESOLVED, That effective January 1, 1999, Article X.E.1. and 2.
of the Thrift Plan for Retail Employees of Conoco Inc. shall be amended to read
as follows:

                                       4
<PAGE>   5

         E.       Compliance with Minimum Distribution Rules

                  1.       General Rule

                           Notwithstanding any other provision of this Plan, a
                           Member, Beneficiary Member, Terminated Member,
                           Retired Member, or Alternate Payee shall receive
                           minimum Distributions. "Minimum Distributions" shall
                           mean distributions in such amounts as are required to
                           satisfy section 401(a)(9) of the Code, the incidental
                           death benefit rule of section 401(a)(9)(G) of the
                           Code, and regulations under both of those Code
                           sections, and which are made no later than required
                           to satisfy section 401(a)(9) of the Code and
                           regulations thereunder. Except as provided in Article
                           X.E.2., 3. and 4. below, a Member, Beneficiary
                           Member, Terminated Member, Retired Member, or
                           Alternate Payee shall receive his Minimum
                           Distributions on or before his Required Beginning
                           Date in the form of a lump sum payment of his entire
                           Vested Account.

                           In the case of a Member, Terminated Member or Retired
                           Member, who reaches age 70 1/2 prior to the year
                           2000, or a 5 percent owner of the Company, the
                           Required Beginning Date is April 1 of the year
                           following the year in which such individual turned
                           age 70 1/2.

                           In the case of a Member, Terminated Member, or
                           Retired Member, who reaches age 70 1/2 on or after
                           January 1, 2000, the Required Beginning Date is April
                           1 of the calendar year following the later of the
                           calendar year in which the individual reaches age 70
                           1/2 or the calendar year in which the individual
                           ceases to be employed by the Corporate Employer.

                           In the case of a Beneficiary Member or Alternate
                           Payee, the Required Beginning Date is December 31 of
                           the year in which the Member to whom the benefit
                           relates turns or would have turned age 70 1/2 prior
                           to the year 2000.

                           In the case of a Beneficiary Member or Alternate
                           Payee, the Required Beginning Date is December 31 of
                           the later of the calendar year in which the Member to
                           whom the benefit relates turns 70 1/2, would have
                           turned age 70 1/2, or ceases to be employed by the
                           Corporate Employer, if such Member turned or would
                           have turned age 70 1/2 on or after January 1, 2000.

                                      5
<PAGE>   6

                  2.       Active Employee

                           If a Member, who attains age 70 1/2 before January 1,
                           2000, has not terminated employment with Conoco on
                           April 1 of the calendar year following the calendar
                           year in which he attained age 70 1/2, his Minimum
                           Distribution will begin no later than that date in
                           the form of a Lifetime Periodic Payment.

         Witness the signature this 31st day of December 1999.

                                         /s/ Archie W. Dunham
                                         ---------------------------------------
                                         Archie W. Dunham

                                       6