<PAGE>
                                                                   EXHIBIT 10.35
                                                              Contract #: T1174F

                        NORTHERN BORDER PIPELINE COMPANY
                        U. S. SHIPPERS SERVICE AGREEMENT

This Agreement (the "Service Agreement") is made and entered into at Omaha,
Nebraska as of October 29, 2001, by and between NORTHERN BORDER PIPELINE
COMPANY, hereinafter referred to as "Company" and ENRON NORTH AMERICA CORP.,
a(n) Delaware corporation, hereinafter referred to as "Shipper".

WHEREAS, Company's investors and lenders rely on Certificates of Public
Convenience and Necessity granted by the Federal Energy Regulatory Commission
and on the Tariff for the return of and the return on all funds invested in or
loaned to the Company; and

WHEREAS, the transportation of natural gas shall be effectuated pursuant to Part
157 or Part 284 of the Federal Energy Regulatory Commission's Regulations; and

WHEREAS, Company recognizes that it will be a condition to the initial
effectiveness of this Service Agreement that, notwithstanding any other
provision of the Tariff or this Service Agreement, the FERC and all other
appropriate federal governmental authorities and/or agencies in the United
States shall have issued, under terms and conditions acceptable to Shipper, all
final nonappealable authorizations and certificates;

NOW THEREFORE, in consideration of their respective covenants and agreements
hereinafter set out, the parties hereto covenant and agree as follows:

ARTICLE 1 - BASIC RECEIPTS

Shipper shall on each day beginning with Shipper's Billing Commencement Date, as
defined in Section 1 of the General Terms and Conditions of Company's FERC Gas
Tariff, be entitled to tender and, following tender, deliver to Company, at each
of Shipper's Points of Receipt, a quantity of gas not in excess of the Daily
Receipt Quantity for such Point of Receipt for such day, as defined in such
Section 1, and Company shall, on such day, take receipt of the quantity of gas
so tendered and delivered by Shipper at such Point of Receipt.

ARTICLE 2 - EXCESS RECEIPTS

If Shipper shall desire to tender to Company on any day beginning with Shipper's
Billing Commencement Date, at any of Shipper's Points of Receipt, a quantity of
gas in excess of Shipper's Daily Receipt Quantity for such Point of Receipt for
such day, it shall notify Company of such desire. If Company in its sole
judgment, determines that it has available the necessary capacity to







                                      -1-
<PAGE>

                        NORTHERN BORDER PIPELINE COMPANY
                        U. S. SHIPPERS SERVICE AGREEMENT



receive and transport all or any part of such excess quantity and make
deliveries in respect thereof, and that the performance of Company's obligations
to other Shippers under their Agreements will not be adversely affected thereby,
Company may elect to receive from Shipper said excess quantity or part thereof,
and shall so notify Shipper. Scheduling of Excess Receipts will be in accordance
with Section 10 of the General Terms and Conditions.




                                      -2-
<PAGE>


                        NORTHERN BORDER PIPELINE COMPANY
                        U. S. SHIPPERS SERVICE AGREEMENT


ARTICLE 3 - DELIVERIES

Company shall deliver gas to Shipper at the Point(s) of Delivery and under the
conditions specified in Exhibit A hereto and in accordance with Section l3 of
the General Terms and Conditions.

ARTICLE 4 - PAYMENTS

Shipper shall make payments to Company in accordance with Rate Schedules T-1 and
OT-1 and the other applicable terms and provisions of this Service Agreement.

ARTICLE 5 - CHANGE IN TARIFF PROVISIONS

Upon notice to Shipper, Company shall have the right to file with the Federal
Energy Regulatory Commission any changes in the terms of any of its Rate
Schedules, General Terms and Conditions or Form of Service Agreement as Company
may deem necessary, and to make such changes effective at such times as Company
desires and is possible under applicable law. Shipper may protest any filed
changes before the Federal Energy Regulatory Commission and exercise any other
rights it may have with respect thereto.

ARTICLE 6 - CANCELLATION OF PRIOR AGREEMENTS

When this Service Agreement becomes effective, it shall supersede, cancel and
terminate the following Agreements: -none-


ARTICLE 7 - TERM

This Service Agreement shall become effective upon its execution and shall under
all circumstances continue in effect in accordance with the Tariff for one (1)
year after the Billing Commencement Date, defined herein as November 1, 2002. If
the primary term of this Service Agreement shall be one year or more, then this
Service Agreement shall continue in effect thereafter until extended or
terminated in accordance with Section 5 of the Rate Schedule T-1. Shipper shall
give Company not less than six (6) months prior written notice of Shipper's
intent to terminate this Service Agreement. Service rendered pursuant to this
Service Agreement shall be abandoned upon termination of this Service Agreement.

This Service Agreement shall automatically terminate and be of no further force
and effect unless Shipper shall furnish a proper security arrangement, in
accordance with Subsection 9.1 of Rate Schedule T-1, to the Company within
thirty (30) days after notice from the Company subsequent to the occurrence of
any of the following events:



                                      -3-
<PAGE>

                        NORTHERN BORDER PIPELINE COMPANY
                        U. S. SHIPPERS SERVICE AGREEMENT


         The filing by Shipper or its parent of a voluntary petition in
         bankruptcy or the entry of a decree or order by a court having
         jurisdiction in the premises adjudging the Shipper as bankrupt or
         insolvent, or approving as properly filed a petition seeking
         reorganization, arrangement, adjustment or composition of or in respect
         of the Shipper under the Federal Bankruptcy Act or any other applicable
         federal or state law, or appointing a receiver, liquidator, assignee,
         trustee, sequestrator (or other similar official) of the Shipper or any
         substantial part of its property, or the ordering of the winding-up or
         liquidation of its affairs, with said order or decree continuing
         unstayed and in effect for a period of sixty (60) consecutive days.

         A failure by Shipper to pay in full the amount of any invoice rendered
         by Company shall continue for ten (10) days from the date payment is
         due.

Termination of this U.S. Shippers Service Agreement shall not relieve Company
and Shipper of the obligation to correct any Receipt or Delivery Imbalances
hereunder, or Shipper to pay money due hereunder to Company and shall be in
addition to any other remedies that Company may have.

ARTICLE 8 - APPLICABLE LAW AND SUBMISSION TO JURISDICTION

This Service Agreement and Company's Tariff, and the rights and obligations of
Company and Shipper thereunder are subject to all relevant United States lawful
statutes, rules, regulations and orders of duly constituted authorities having
jurisdiction. Subject to the foregoing, this Service Agreement shall be governed
by and interpreted in accordance with the laws of the State of Nebraska. For
purposes of legal proceedings, this Service Agreement shall be deemed to have
been made in the State of Nebraska and to be performed there, and the Courts of
that State shall have jurisdiction over all disputes which may arise under this
Service Agreement, provided always that nothing herein contained shall prevent
the Company from proceeding at its election against the Shipper in the Courts of
any other state, Province or country.

At the Company's request, the Shipper shall irrevocably appoint an agent in
Nebraska to receive, for it and on its behalf, service of process in connection
with any judicial proceeding in Nebraska relating to this Service Agreement.
Such service shall be deemed completed on delivery to such process agent (even
if not forwarded to and received by the Shipper). If said agent ceases to act as
a process agent within Nebraska on behalf of Shipper, the Shipper shall appoint
a substitute process agent within Nebraska and deliver to the Company a copy of
the new agent's acceptance of that appointment within 30 days.



                                      -4-
<PAGE>



                        NORTHERN BORDER PIPELINE COMPANY
                        U. S. SHIPPERS SERVICE AGREEMENT


ARTICLE 9 - SUCCESSORS AND ASSIGNS

Any person which shall succeed by purchase, amalgamation, merger or
consolidation to the properties, substantially as an entirety, of Shipper or of
Company, as the case may be, and which shall assume all obligations under
Shipper's Service Agreement of Shipper or Company, as the case may be, shall be
entitled to the rights, and shall be subject to the obligations, of its
predecessor under Shipper's Service Agreement. Either party to a Shipper's
Service Agreement may pledge or charge the same under the provisions of any
mortgage, deed of trust, indenture, security agreement or similar instrument
which it has executed, or assign such Service Agreement to any affiliated Person
(which for such purpose shall mean any person which controls, is under common
control with or is controlled by such party). Nothing contained in this Article
9 shall, however, operate to release predecessor Shipper from its obligation
under its Service Agreement unless Company shall, in its sole discretion,
consent in writing to such release, which it shall not do unless it concludes
that, on the basis of the facts available to it, such release is not likely to
have a substantial adverse effect upon other Shippers or other Persons who may
become liable to provide funds to Company to enable it to meet any of its
obligations. Company shall not release any Shipper from its obligations under
its Service Agreement without the written consent of the other Shippers unless:
(a) such release is effected pursuant to an assignment of obligations by such
Shipper, and the assumption thereof by the assignee, and the terms of such
assignment and assumption render the obligations being assigned and assumed no
more conditional and no less absolute than those at the time provided therein;
and (b) such release is not likely to have a substantial adverse effect upon
Company or the other Shippers. For the purposes hereof, and without limiting the
generality of the foregoing, any release of any Shipper from its obligations
under its Service Agreement shall be deemed likely to have a substantial adverse
effect upon Company or the other Shippers if the assignee of such obligations
has a credit standing which is not at least equal to the credit standing of the
assignor of such obligations (credit standings in each case as reflected by the
ratings on outstanding debt securities by Moody's Investors Service, Standard
and Poor's Corporation or another rating service acceptable to all Shippers to
the extent available or by other appropriate objective measures). Shipper shall,
at Company's request, execute such instruments and take such other action as may
be desirable to give effect to any such assignment of Company's rights under
such Shipper's Service Agreement or to give effect to the right of a Person whom
the Company has specified pursuant to Section 6 of the General Terms and
Conditions of Company's FERC Gas Tariff as the Person to whom payment of amounts
invoiced by Company shall be made; provided, however, that: (a) Shipper shall
not be required to execute any such instruments or take any such other action
the effect of which is to modify the respective rights and obligations of either







                                      -5-
<PAGE>

                        NORTHERN BORDER PIPELINE COMPANY
                        U. S. SHIPPERS SERVICE AGREEMENT


Shipper or Company under this Agreement; and (b) Shipper shall be under no
obligation at any time to determine the status or amount of any payments which
may be due from Company to any Person whom the Company has specified pursuant to
said Section 6 as the Person to whom payment of amounts invoiced by Company
shall be made.




                                      -6-
<PAGE>

                        NORTHERN BORDER PIPELINE COMPANY
                        U. S. SHIPPERS SERVICE AGREEMENT


ARTICLE 10 - LOSS OF GOVERNMENTAL AUTHORITY, GAS SUPPLY, TRANSPORTATION OR
MARKET

Without limiting its other responsibilities and obligations under this Service
Agreement, the Shipper acknowledges that it is responsible for obtaining and
assumes the risk of loss of the following: (1) gas removal permits, (2) export
and import licenses, (3) gas supply, (4) markets and (5) transportation upstream
and downstream of the Company's pipeline system. Notwithstanding the loss of one
of the items enumerated above, Shipper shall continue to be liable for payment
to the Company of the transportation charges as provided for in this Service
Agreement.

ARTICLE 11 - OTHER OPERATING PROVISIONS

(This Article to be utilized when necessary to specify other operating
provisions.)

ARTICLE 12 - EXHIBIT A OF SERVICE AGREEMENT, RATE SCHEDULES AND GENERAL TERMS
AND CONDITIONS

Company's Rate Schedules and General Terms and Conditions, which are on file
with the Federal Energy Regulatory Commission and in effect, and Exhibit A
hereto are all applicable to this Service Agreement and are hereby incorporated
in, and made a part of, this Service Agreement. In the event that the terms and
conditions herein are in conflict with the General Terms and Conditions in
Company's FERC Gas Tariff, the terms and conditions of this Service Agreement
are controlling.

IN WITNESS WHEREOF, The parties hereto have caused this Agreement to be duly
executed as of the day and year first set forth above.

                         NORTHERN BORDER PIPELINE COMPANY

                         By:   Northern Plains Natural Gas Company,
                               Operator

                         By:  /s/ Paul Miller
                             --------------------------------------------------

                         Title:   Director of Marketing, Interstate Pipelines
                                -----------------------------------------------



                                      -7-
<PAGE>

                        NORTHERN BORDER PIPELINE COMPANY
                        U. S. SHIPPERS SERVICE AGREEMENT


ATTEST:                                    ENRON NORTH AMERICA CORP.

                                           By: /s/Hunter Shively
------------------------------                --------------------------------

                                           Title:            VP
                                                  ----------------------------





                                      -8-
<PAGE>


                        NORTHERN BORDER PIPELINE COMPANY
                        U. S. SHIPPERS SERVICE AGREEMENT



                  EXHIBIT A TO U.S. SHIPPERS SERVICE AGREEMENT

COMPANY:                              Northern Border Pipeline Company


COMPANY'S ADDRESS:                    1111 South 103rd Street
                                      Omaha, Nebraska  68l24-1000

SHIPPER:                              Enron North America Corp.
                                      Attn: Geoff Storey

SHIPPER'S ADDRESS:                    1400 Smith Street, Suite 3234C
                                      Houston, TX  77002



<Table>
<Caption>
                                                           Maximum      Minimum         Maximum
                         Role            Maximum            Receipt     Delivery         Receipt         Minimum
                        (Notes           Quantity          Pressure     Pressure       Temperature     Temperature
Points                 1 and 3)         (MCF/Day)           (PSIG)       (PSIG)       ((Degree)F )     ((Degree)F )
--------------------------------------------------------------------------------------------------------------------


<S>                   <C>               <C>                <C>          <C>            <C>             <C>
Ventura, IA              RD                27,600             --           --              --             --
                         TP                27,600             --           --              --             --
                         PD                27,600             --          820              --             --
                         DD                27,600             --           --              --             --

Grundy Center, IA        RD                27,600             --           --              --             --
(Secondary-Note 2)       TP                27,600             --           --              --             --
                         PD                27,600             --          800              --             32
                         DD                27,600             --           --              --             --

Beaman, IA               RD                 5,100             --           --              --             --
(Secondary-Note 2)       TP                27,600             --           --              --             --
                         PD                 5,100             --          839              --             32
                         DD                 5,100             --           --              --             --

Tama, IA                 RD                   880             --           --              --             --
(Secondary-Note 2)       TP                27,600             --           --              --             --
                         PD                   880             --          816              --             32
                         DD                   880             --           --              --             --

Amana, IA                RD                16,350             --           --              --             --
(Secondary-Note 2)       TP                27,600             --           --              --             --
                         PD                16,350             --          783              --             32
                         DD                16,350             --           --              --             --
</Table>




                                      -9-
<PAGE>


                        NORTHERN BORDER PIPELINE COMPANY
                        U. S. SHIPPERS SERVICE AGREEMENT


            EXHIBIT A TO U.S. SHIPPERS SERVICE AGREEMENT (continued)

<Table>
<Caption>
                                                           Maximum      Minimum         Maximum
                         Role            Maximum            Receipt     Delivery         Receipt         Minimum
                        (Notes           Quantity          Pressure     Pressure       Temperature     Temperature
Points                 1 and 3)         (MCF/Day)           (PSIG)       (PSIG)       ((Degree)F )     ((Degree)F )
--------------------------------------------------------------------------------------------------------------------


<S>                   <C>               <C>                <C>          <C>            <C>             <C>

Harper, IA               RD                27,600             --           --              --             --
                         TP                27,600             --           --              --             --
                         PD                27,600             --          712              --             32
                         DD                27,600             --           --              --             --


Total Maximum
Receipt Quantity              27,600 Mcf/day
</Table>


                               - - - - - - - - - -



Note 1:    The point role will be either PR for physical receipts, RD for
           receipt by displacement, TP for transfer points, PD for physical
           deliveries, and DD for delivery by displacement.

Note 2:    For receipt or delivery of gas by displacement, Company cannot and
           does not have an obligation to physically deliver or receive gas at
           these points. Volumes will be delivered or received at these point(s)
           only to the extent that corresponding equal or greater volumes are
           received or delivered by other parties at these points on the same
           day. These corresponding volumes will be used to displace volumes
           nominated for delivery or receipt by Shipper.


This Exhibit A is made and entered into as of _____________________________,
2001. On the effective date, it shall supersede the Exhibit A dated as of N/A.

The effective date of this Exhibit A is November 1, 2001.


                              NORTHERN BORDER PIPELINE COMPANY
                              By:   Northern Plains Natural Gas Company,
                                    Operator
                              By:    /s/ Paul F. Miller
                                 -----------------------------------------------

                              Title: Director of Marketing, Interstate Pipelines
                                    --------------------------------------------


ATTEST:                       ENRON NORTH AMERICA CORP.

                              By:   Hunter Shively
--------------------------       -----------------------------------------------


                              Title: VP
                                    --------------------------------------------





                                      -10-