<PAGE>








                                                                     EXHIBIT 2.5

================================================================================



                           PETROLEUM GEO-SERVICES ASA,

                                   AS ISSUER,

                       EACH OF THE GUARANTORS NAMED HEREIN

                                       and

                    LAW DEBENTURE TRUST COMPANY OF NEW YORK,

                                   AS TRUSTEE

                          FIRST SUPPLEMENTAL INDENTURE

                          Dated as of November 5, 2003

                                       to

                     Indenture dated as of November 5, 2003

                     $745,948,810 10% Senior Notes due 2010

                                       and

                      $250,000,000 8% Senior Notes due 2006




================================================================================



<PAGE>






                                TABLE OF CONTENTS


<TABLE>
<CAPTION>

                                                                              Page
                                                                              ----
<S>            <C>                                                            <C>

                                   ARTICLE I.
                                   DEFINITIONS

SECTION 1.1.   Terms Defined in the Original Indenture.........................2
SECTION 1.2.   Certain Definitions.............................................2

                                   ARTICLE II.
                                    THE NOTES

SECTION 2.1.   Form and Dating.................................................6
SECTION 2.2.   Title and Amount................................................6
SECTION 2.3.   Place of Payment................................................7
SECTION 2.4.   No Additional Amounts...........................................7
SECTION 2.5.   Default Interest................................................7
SECTION 2.6.   Guarantee.......................................................7

                                  ARTICLE III.
                                   REDEMPTION

SECTION 3.1.   Optional Redemption.............................................7

                                   ARTICLE IV.
                              ADDITIONAL COVENANTS

SECTION 4.1.   Negative Pledge.................................................7
SECTION 4.2.   Term Loan Facility Amendments...................................9
SECTION 4.3.   Delivery of Information........................................10
SECTION 4.4.   Payment Currency...............................................10
SECTION 4.5.   Offer to Purchase Upon a Change of Control.....................10
SECTION 4.6.   Transactions with Affiliates...................................13
SECTION 4.7.   Change of Business.............................................14
SECTION 4.8.   Insurance......................................................14
SECTION 4.9.   Ranking........................................................14
SECTION 4.10.  Group and PGS Subsidiary Indebtedness..........................14
SECTION 4.11.  Project Finance................................................15
SECTION 4.12.  Environmental Laws.............................................15
SECTION 4.13.  Payment of Dividends by the Company............................16
SECTION 4.14.  Asset Dispositions.............................................17
SECTION 4.15.  Major Proceeds.................................................17
SECTION 4.16.  Rating by Rating Agencies......................................18
SECTION 4.17.  Consent for Certain Term Loan Facility Amendments and Waivers..19
</TABLE>


                                      (i)

<PAGE>

<TABLE>

<S>            <C>                                                            <C>

                                   ARTICLE V.
                          ADDITIONAL EVENTS OF DEFAULT

SECTION 5.1.   Additional Events of Default...................................19
SECTION 5.2.   Change to Events of Default in Original Indenture..............20

                                   ARTICLE VI.
                            MISCELLANEOUS PROVISIONS

SECTION 6.1.   Table of Contents, Headings, etc...............................20
SECTION 6.2.   Counterpart Originals..........................................20
SECTION 6.3.   Governing Law..................................................20
SECTION 6.4.   The Trustee....................................................21
</TABLE>


                                      (ii)

<PAGE>




         FIRST SUPPLEMENTAL INDENTURE dated as of November 5, 2003 between
Petroleum Geo-Services ASA, a Norwegian public limited liability company (the
"Company"), the Guarantors named on the signature page hereof (the "Guarantors")
and Law Debenture Trust Company of New York, as trustee (the "Trustee").

                             RECITALS OF THE COMPANY

         WHEREAS, the Company and each Guarantor has executed and delivered to
the Trustee an indenture, dated as of November 5, 2003 (the "Original Indenture"
and as supplemented by this First Supplemental Indenture, the "Indenture"),
providing for the issuance by the Company from time to time of its unsecured
debentures, notes or other evidences of indebtedness (the "Securities"),
issuable in one or more series;

         WHEREAS, in connection with the restructuring of the Company's debt
obligations and recapitalization as contemplated in that Modified First Amended
Plan of Reorganization for the Company filed in In re Petroleum Geo-Services ASA
as debtor, U.S. Bankruptcy Court, Southern District of New York, case no
03-14786 (BRL) (the "Restructuring"), the Company has duly authorized and
desires to cause to be issued pursuant to the Original Indenture two series of
Securities, one series to be designated the "10% Senior Notes due 2010" (the
"Notes due 2010") and the other series to be designated the "8% Senior Notes due
2006" (the "Notes due 2006" and, together with the Notes due 2010, the "Notes");

         WHEREAS, the Company desires to cause the issuance of the Notes
pursuant to Section 2.01 of the Original Indenture, which section permits the
execution of indentures supplemental thereto to establish the terms of
Securities of any series;

         WHEREAS, the Guarantors are subsidiaries of the Company, will derive
substantial benefits from the issuance of the Notes which will allow the
consummation of the Restructuring and are willing to execute and deliver this
Supplemental Indenture in order to allow the issuance of the Notes and the
consummation of the Restructuring.

         WHEREAS, Section 9.01 of the Original Indenture permits the execution
of supplemental indentures without the consent of any Holder (as defined
therein) (i) to add to the covenants of the Company for the benefit of the
Holders of all or any series of Securities (Section 9.01(6)), (ii) to add any
additional Events of Default with respect to all or any series of Securities
(Section 9.01(7)), (iii) to change or eliminate any provision of the Original
Indenture with respect to Securities of any series when there is no Security of
such series outstanding (Section 9.01(8)) and (iv) to establish the form or
terms of Securities of any series (Section 9.01(9));

         WHEREAS, pursuant to Section 9.01 of the Original Indenture the Company
has requested that the Trustee join in the execution of this First Supplemental
Indenture to establish the form and terms of the Notes;

         WHEREAS, all things necessary have been done to make the Notes, when
executed by the Company and authenticated and delivered hereunder and duly
issued by the Company, the valid obligations of the Company, and to make this
First Supplemental Indenture a valid agreement of the Company and the
Guarantors, in accordance with their and its terms.



<PAGE>

         NOW, THEREFORE, for good and valid consideration, the receipt of which
is hereby acknowledged, the Company, the Guarantors and the Trustee hereby agree
that the following provisions shall supplement the Original Indenture:

                                   ARTICLE I.
                                   DEFINITIONS

     SECTION 1.1. Terms Defined in the Original Indenture.

         Each capitalized term used but not defined in this First Supplemental
Indenture shall have the meaning assigned to such term in the Original
Indenture.

     SECTION 1.2.  Certain Definitions.

         The following definitions are hereby added to, or, in the case of the
definitions of the term "Redemption Price" and "Subsidiary", substituted in lieu
of, the definition contained in Section 1.01 of the Original Indenture, but only
with respect to each series of the Notes:

         "Acting in Concert" means acting together pursuant to an agreement or
understanding (whether formal or informal).

         "Adjusted Total Debt" means, at any time, Total Debt:

         (a) less any Financial Indebtedness under the Bonding Facility and the
Working Capital Facility at that time;

         (b) less any scheduled repayments of Financial Indebtedness which fall
due substantially concurrent with such time; and

         (c) plus any Financial Indebtedness which is scheduled to be incurred
substantially concurrent with such time.

         "Affiliate Transaction" has the meaning assigned to that term in
Section 4.6.

         "Bonding Facility" means a facility or facilities made, or to be made,
available for the issuance of Bonds by banks or financial institutions on behalf
of members of the Group in an aggregate principal amount which does not exceed
US$40,000,000 (or its equivalent in any other currency or currencies).

         "Bonds" means guarantees, bonds (being bid bonds, performance bonds or
other bonds), indemnities, letters of credit, documentary credits and other
equivalent instruments issued or to be issued in connection with the trading
activities of the Group.

         "Change of Control" means any Person or group of Persons Acting in
Concert gaining Control of the Company.

         "Change of Control Date" has the meaning assigned to that term in
Section 4.5.



                                     - 2 -
<PAGE>


         "Consolidated Net Income" means, for any period, the consolidated net
income of the Company for such period as determined by reference to the
Company's consolidated financial statements delivered pursuant to Section 4.3.

         "Control" means any person or group of persons Acting in Concert
(whether directly or indirectly) becoming the beneficial owner of the Voting
Stock of the Company carrying the right to exercise a minimum of 51% of the
votes capable of being cast in general meetings of the Company.

         "Dangerous Substance" means any radioactive emissions, noise, any
natural or artificial substance (whether in the form of a solid, liquid, gas or
vapor) the generation, transportation, storage, treatment, use or disposal of
which (whether alone or in combination with any other substance) including
(without limitation) any controlled, special, hazardous, toxic, radioactive or
dangerous substance or waste, gives rise to a material risk of causing harm to
man or any other living organism or damage to the Environment.

         "Deemed Amendments" shall have the meaning set forth in Section 4.2.

         "EBITDA" means, at any time, the Consolidated Net Income for the period
of four fiscal quarters ending on the last day of the period for which the most
recent financial statements of the Group delivered under Section 4.3 relate (the
"Measurement Period") but before taking into account (a) Interest Expense, (b)
Tax, (c) any fees, costs and expenses payable during that Measurement Period
under, or in relation to, the Restructuring, (d) any other non-cash charges
which are, or are in connection with, exceptional or extraordinary items; and
after adding back all amounts provided for depreciation and amortization during
that Measurement Period and including:

                  (i) the earnings before interest and other finance charges,
         Tax, depreciation and amortization of a Subsidiary or business or the
         net earnings of an asset acquired by any member of the Group during the
         relevant Measurement Period for the part of that Measurement Period
         when it was not a Subsidiary of that member of the Group and/or the
         business or asset was not owned by that member of the Group (if any);
         and

                  (ii) any earnings attributable to minority interests,

but excluding the earnings before interest and other finance charges, Tax,
depreciation and amortization attributable to any member of the Group or to any
business or assets sold during that Measurement Period and, for the avoidance of
doubt, calculated before any investment in the Multi-Client Libraries.

         "Environment" means all, or any of, (i) the air (including, without
limitation, the air within buildings and the air within other natural or
man-made structures above or below ground), (ii) water (including, without
limitation, ground and surface water) and (iii) land (including, without
limitation, surface and sub-surface soil).

         "Environmental Law" means all applicable laws (including, without
limitation, common law), regulations, directing codes of practice, circulars,
guidance notices and the like






                                     - 3 -
<PAGE>

having the force of law concerning pollution of the Environment or the
generation, transportation, storage, treatment or disposal of Dangerous
Substances but excluding any such laws, regulations, directing codes of practice
guidance notices or the like which have as their primary purpose the securing of
the health or safety of persons at work.

         "Environmental License" means any permit, license, authorization,
consent or other approval required by any Environmental Law.

         "Global Notes" shall have the meaning set forth in Section 2.1.

         "Interest Expense" means, in relation to any period, the aggregate
amount of interest and any other finance charges (whether or not paid or
payable) accrued by the Group in that period in respect of Financial
Indebtedness determined in accordance with GAAP.

         "Lien" means, with respect to any property or asset, any mortgage,
lien, pledge, charge, assignment by way of security, hypothecation or other
security interest securing any obligation of any Person or any other agreement
or arrangement having a similar effect.

         "Major Proceeds" has the meaning ascribed to such term in the Term Loan
Facility.

         "Material Adverse Effect" means a material adverse effect on the
consolidated financial condition or business of the Group taken as a whole or
the ability of the Company to perform its payment obligations or any other
material obligations under the Indenture or the validity or enforceability of
the Indenture.

         "Modification" has the meaning ascribed to such term in Section 4.2.

         "Moody's" means Moody's Investor's Service, Inc. and its successors.

         "Multi-Client Libraries" means libraries of seismic data which have
been acquired for licensing to multiple clients.

         "Notes" shall have the meaning set forth in the recitals hereof.

         "Obligor" means, individually and collectively, the Company and each
Guarantor.

         "Offer Amount" has the meaning assigned to that term in Section 4.5.

         "Offer Period" has the meaning assigned to that term in Section 4.5.

         "Original Indenture" shall have the meaning set forth in the recitals
hereof.

         "PGS Subsidiary" means any Subsidiary of the Company other than a
Project Company.

         "Project" means the acquisition, creation, construction, improvement or
development of an asset where the indebtedness incurred to finance the whole or
part thereof is owed by a Project Company solely on a limited recourse basis to
the applicable Project Company




                                     - 4 -
<PAGE>

(where such Project Company is formed solely or principally for the purpose of
the relevant Project) and/or to such asset (or any derivative asset thereof).

         "Purchase Date" has the meaning assigned to that term in Section 4.5.

         "Purchase Offer" has the meaning assigned to that term in Section 4.5.

         "Redemption Price" means, with respect to any Note to be redeemed, the
price as set forth in paragraph 4 of the Notes.

         "Restructuring" has the meaning assigned to that term in the recitals
hereof.

         "Sale and Leaseback Type Transactions" has the meaning assigned to that
term in Section 4.1.

         "S&P" means Standard & Poor's Rating Services, a division of The
McGraw-Hill Company, Inc., and its successors.

         "Subsidiary" means an entity from time to time of which a Person
directly or indirectly owns or controls shares representing more than 50% of the
Voting Stock or, by agreement or otherwise, has direct or indirect control. For
the purposes of this definition, "control" means the power to direct the
management and the policies of the entity whether through the ownership of
voting capital, by contract or otherwise.

         "Tax" means any tax, levy, impost, duty or other charge or withholding
of a similar nature (including any penalty or interest payable in connection
with any failure to pay or any delay by an Obligor in paying any of the same).

         "Term Loans" means the loans extended to the Company pursuant to the
Term Loan Facility.

         "Total Debt" means, at any time, the aggregate outstanding principal,
capital or nominal amount of the Financial Indebtedness of the members of the
Group at that time but excluding:

         (a) any repayments of Financial Indebtedness which are made at that
time with the proceeds of Financial Indebtedness incurred at that time; and

         (b) for the avoidance of doubt, any Project Finance Indebtedness
outstanding at that time.

         "Voting Stock" of a Person means all classes of Capital Stock or other
interests (including partnership interests) of such Person then outstanding and
normally entitled, without regard to the occurrence of any contingency, to vote
in the election of directors, managers or trustees thereof.

         "Working Capital Facility" means a facility or facilities made, or to
be made, available to members of the Group to finance the Group's working
capital requirements which in




                                     - 5 -
<PAGE>

aggregate principal amount does not exceed US$70,000,000 (or its equivalent in
any other currency or currencies).

                                   ARTICLE II.
                                    THE NOTES

    SECTION 2.1. Form and Dating.

         The Notes and the Trustee's certificate of authentication shall be
substantially in the form of Exhibit A to this First Supplemental Indenture,
which is hereby incorporated into this Indenture. The terms and provisions
contained in the Notes of each series shall constitute, and are hereby expressly
made, a part of this First Supplemental Indenture and to the extent applicable,
the Company and the Trustee, by their execution and delivery of this First
Supplemental Indenture, expressly agree to such terms and provisions and to be
bound thereby.

         The Notes shall be issuable in denominations of $1.00 and integral
multiples thereof; provided, however, that each Note or Notes issued upon any
registration of transfer or exchange of any Note pursuant to Section 2.08 of the
Original Indenture shall be issued in denominations of $1,000 or integral
multiples thereof, except that not more than one new Note so being issued in
respect of the Note being surrendered may be in a denomination that is not
$1,000 or an integral multiple thereof. The Notes of each series will initially
be issued in permanent global form, substantially in the form of Exhibit A
attached hereto (the "Global Notes"). Each Global Note of a series shall
represent such of the outstanding Notes of that series as shall be specified
therein and shall provide that it shall represent the aggregate amount of
outstanding Notes of that series from time to time endorsed thereon and that the
aggregate amount of outstanding Notes of that series represented thereby may
from time to time be reduced to reflect exchanges and redemptions. Any
endorsement of a Global Note of a series to reflect the amount, or any decrease
in the amount, of outstanding Notes of that series represented thereby shall be
made by the Trustee in accordance with written instructions or such other
written form of instructions as is customary for the Depositary, from the
Depositary or its nominee on behalf of any Person having a beneficial interest
in the Global Note of that series.

         The Company initially appoints The Depository Trust Company and the
Trustee to act as Depositary and Security Custodian, respectively, with respect
to the Global Notes.

     SECTION 2.2. Title and Amount.

         The Notes due 2010 shall be entitled the "10% Senior Notes due 2010,"
and the Notes due 2006 shall be entitled the "8% Senior Notes due 2006." The
Trustee shall authenticate and deliver Notes due 2010 for original issue in the
aggregate principal amount of $745,948,810, and the Trustee shall authenticate
and deliver Notes due 2006 for original issue in the aggregate principal amount
of $250,000,000, in each case upon a Company Order for the authentication and
delivery of such series of Notes and satisfaction of Sections 2.01 and 2.04 of
the Indenture. Such order shall specify the amount of the Notes of each series
to be authenticated, the date on which the original issue of Notes of each
series is to be authenticated and the name or names of the initial Holder or
Holders. The aggregate principal amount of Notes due 2010 that may be
authenticated and delivered under the Indenture may not exceed $745,948,810, and
the aggregate




                                     - 6 -
<PAGE>

principal amount of Notes due 2006 that may be authenticated and delivered under
the Indenture may not exceed $250,000,000 (except for Notes of a series
authenticated and delivered upon registration of transfer of, or in exchange
for, or in lieu of, other Notes of that series pursuant to Section 2.08, 2.09,
2.12, 2.17, 3.07 or 9.05 of the Indenture).

     SECTION 2.3. Place of Payment.

         The Place of Payment for the Notes shall be in the Borough of
Manhattan, The City of New York.

     SECTION 2.4. No Additional Amounts.

         No Additional Amounts shall be payable with respect to the Notes.

     SECTION 2.5. Default Interest.

         Notwithstanding Section 2.14 of the Original Indenture, if the Company
defaults in a payment of interest on the Notes, the Company shall pay the
defaulted interest plus, to the extent lawful, interest on the defaulted
interest, in each case at an annual rate equal to the non-default rate provided
in the Notes plus, upon the expiration of any applicable cure period, 2%.

     SECTION 2.6. Guarantee.

         The Notes issued hereunder are entitled to the benefits of the
Guarantee under Article X of the Original Indenture and any other covenants and
undertakings of the Guarantors under the Original Indenture.

                                   ARTICLE III.
                                   REDEMPTION

     SECTION 3.1.  Optional Redemption.

                  There shall be no sinking fund for the retirement of Notes of
either series. The Company, at its option, may redeem the Notes of each series
in accordance with the provisions of paragraph 4 of the Notes of that series and
Article III of the Original Indenture.

                                  ARTICLE IV.
                              ADDITIONAL COVENANTS

         The following covenants are hereby added to the covenants of the
Company for the benefit of the Holders of each series of the Notes, and such
covenants are expressly being included solely for the benefit of such series:

     SECTION 4.1. Negative Pledge.

         (a)    No Obligor shall (and the Company shall ensure that no Material
Subsidiary will) create or permit to subsist any Lien over any of its assets.



                                     - 7 -
<PAGE>

         (b)    No Obligor shall (and the Company shall ensure that no Material
Subsidiary will) (i) sell, transfer or otherwise dispose of any of its assets on
terms whereby they are or may be leased to or re-acquired or acquired by an
Obligor or any other member of the Group or any of its related entities, or (ii)
sell, transfer or otherwise dispose of any of its receivables on recourse terms,
except for the discounting of bills or notes in the ordinary course of trading,
in each case in circumstances where the arrangement or transaction is entered
into primarily as a method of raising Financial Indebtedness or of financing the
acquisition of an asset. The arrangements and transactions referred to in this
paragraph (b) are "Sale and Leaseback Type Transactions" for the purposes of
this First Supplemental Indenture.

         (c)   Paragraphs (a) and (b) above do not apply to any Lien or Sale and
Leaseback Type Transactions:

               (i)    existing on the Issue Date or, in the case of a Subsidiary
          which becomes a Material Subsidiary after the date of this Indenture,
          existing as at the date that that Subsidiary becomes a Material
          Subsidiary; provided that, in each case, the principal amount secured
          thereby is not subsequently increased;

               (ii)   created over or in respect of an asset to secure Financial
          Indebtedness incurred to finance the acquisition of that asset
          provided that the Financial Indebtedness so secured does not exceed
          100% of the total acquisition costs of that asset and the Lien or Sale
          and Leaseback Type Transaction is limited to that asset;

               (iii)  existing on or in respect of the assets of an entity at
          the time it becomes a Material Subsidiary after the Issue Date, but
          only if (A) the Lien was not created in contemplation of the company
          becoming a Material Subsidiary and (B) the principal amount secured by
          the Lien is not increased after it becomes a Material Subsidiary;

               (iv)   existing on or in respect of assets at the time they are
          acquired by a Material Subsidiary, but only if (A) the Lien was
          existing at the time of the acquisition, (B) the Lien was not created
          in contemplation of the acquisition and (C) the principal amount
          secured by the Lien is not increased after the acquisition;

               (v)    securing or in respect of any Financial Indebtedness
          incurred by any Subsidiaries pursuant to Section 4.10;

               (vi)   created over any U.S. industrial revenue and/or similar
          type of bond or other security;

               (vii)  on capital stock, debt securities or other securities of a
          Person that is not a PGS Subsidiary;

               (viii) any lien arising by operation of law and in the ordinary
          course of trading and not as a result of any default or omission by
          any member of the Group;

               (ix)   relating to accounts receivable of the Company or any of
          the PGS Subsidiaries that have been sold, assigned or otherwise
          transferred to a person other than




                                     - 8 -
<PAGE>

          the Company or a PGS Subsidiary in connection with Financial
          Indebtedness of the type described in paragraph (d) of the definition
          of "Financial Indebtedness", provided that the amount secured by that
          Lien does not exceed 10% of the consolidated total assets of the Group
          (calculated by reference to the then latest audited consolidated
          financial statements of the Group);

               (x)    securing the Working Capital Facility or the Bonding
          Facility;

               (xi)   created pursuant to applications or reimbursement
          agreements pertaining to commercial letters of credit obtained in the
          ordinary course of business;

               (xii)   any retention of title arising in a supplier's standard
          conditions of supply in respect of goods acquired by a Material
          Subsidiary in the ordinary course of business;

               (xiii)  any right of set-off on credit balances of a Material
          Subsidiary where the same arises in the ordinary course of banking
          arrangements for the purpose of netting debit and credit balances; or

               (xiv)   created on or in respect of the assets the subject of a
          Lien or Sale and Leaseback Type Transactions permitted under
          paragraphs (i) to (xiii) above to secure any refinancing of the amount
          thereby secured provided that the principal amount secured by any such
          Lien or Sale and Leaseback Type Transaction may not be increased and
          the maturity of each amount secured may not be extended beyond the
          maturity date provided for in the original documentation in relation
          to such refinanced amount.

     SECTION 4.2. Term Loan Facility Amendments.

         (a)   The Company shall provide the Trustee with prior written notice
of any amendment, supplement, restatement or any other modification to the Term
Loan Facility (the "Modification") which provides any lender under the Term Loan
Facility with the direct or indirect benefit of any guarantee, preference,
financial reporting requirements, representation, warranty, covenant or event of
default (howsoever described) under the terms of the Term Loan Facility which is
not provided to the Holders under the Indenture.

         (b)   Within 90 days of delivery of the notice referred to in clause
(a) above, the Company shall provide to the Trustee a supplemental indenture
amending the terms of the Indenture such that the relevant terms of the
Indenture shall be the same as the amended terms of the Term Loan Facility as
modified by the Modification (the "Deemed Amendments").

         (c)   Clause (b) above does not apply to the Repeating Representations
(as defined in the Term Loan Facility), Clause 19.5 (Change of GAAP), Clause
20.1 (Authorizations), Clause 21.3 (Misrepresentation), Clause 21.8 (Ownership
of Obligors), Clause 21.10 (Unlawfulness), Clause 21.11 (Repudiation) and Clause
27.9 (Change of Currency)of the Term Loan Facility.

         (d)   The Obligors agree to take whatever action the holders of a
majority of the outstanding principal of the Notes may reasonably require to
give effect to the terms of this




                                     - 9 -
<PAGE>

Section 4.2, including, without limitation, the execution of a supplemental
indenture reflecting the terms of the Deemed Amendments.

     SECTION 4.3. Delivery of Information.

         (a)   Financial Statements. The Company shall file with the Trustee (i)
as soon as the same become available, but in any event within 180 days after the
end of each of its fiscal years, its audited consolidated financial statements
for that fiscal year, and (ii) as soon as the same become available, but in any
event within 60 days after the end of each of the first three financial quarters
of each of its fiscal years, the unaudited consolidated financial statements of
the Group for that financial quarter, in each case together with a certificate
signed by an Officer of the Company certifying that no Default is continuing (or
if a Default is continuing, specifying the Default and the steps, if any, being
taken to remedy it) setting out a calculation of the ratio of Adjusted Total
Debt to EBITDA as at the date to which such financial statements have been
prepared. Each set of financial statements delivered by the Company hereunder
shall be prepared in accordance with GAAP and shall be certified by an Officer
of the Company as fairly representing its consolidated financial condition and
operations as at the end of and for the period in relation to which those
financial statements were prepared.

         (b)   Other Information. The Company shall file with the Trustee (i)
copies of all documents delivered by the Company to its shareholders (or any
class thereof) or its creditors generally promptly after such delivery, (ii)
copies of all public filings made by the Company with the SEC (other than
filings which relate solely to the ownership of securities of the Company) or
the Oslo Stock Exchange.

     SECTION 4.4. Payment Currency.

         All payments due under the Notes shall be made in Dollars. To the
fullest extent permitted by applicable law, the obligation of the Company in
respect of any amount due under the Notes shall, notwithstanding any payment in
any other currency (whether pursuant to a judgment or otherwise), be discharged
only to the extent of the amount in Dollars that the party entitled to receive
such payment may, in accordance with normal banking procedures, purchase with
the sum paid in such other currency (after any premium and costs of exchange) in
the city of receipt on the Business Day immediately following the day on which
such party receives such payment. If the amount in Dollars that may be so
purchased for any reason falls short of the amount originally due, the Company
shall pay such additional amounts, in Dollars, as may be necessary to compensate
for the shortfall. Any obligation of the Company not discharged by such
additional payment shall, to the fullest extent permitted by applicable law, be
due as a separate and independent obligation and, until discharged as provided
herein, shall continue in full force and effect. The provisions of the last
paragraph of Section 6.10 of the Original Indenture shall not apply to the
Notes.

     SECTION 4.5. Offer to Purchase Upon a Change of Control.

         (a) Upon the occurrence of a Change of Control (the date of the last
event required for a Change of Control to be effected hereinafter referred to as
the "Change of Control Date"), each Holder of the Notes shall have the right to
require the Company to purchase all or




                                     - 10 -
<PAGE>

any part (equal to $1.00 or an integral multiple thereof) of such Holder's Notes
pursuant to the offer described below (the "Purchase Offer") at an offer price
in cash equal to 101% of the aggregate principal amount thereof to the date of
purchase plus accrued but unpaid interest, if any, to the date of purchase of
such Notes. The Company shall comply, to the extent applicable, with the
requirements of Rule 14e-1 under the Exchange Act and any other securities laws
and regulations thereunder to the extent such laws and regulations are
applicable in connection with the purchase of the Notes as a result of the
Change of Control. To the extent that the provisions of any securities laws or
regulations conflict with the provisions of this covenant, the Company shall
comply with the applicable securities laws and shall not be deemed to have
breached its obligations under this covenant by virtue of such compliance.

         (b)   The Change of Control provisions described in this section shall
be applicable notwithstanding any other provisions of this Indenture. The
Company shall not be required to make a Purchase Offer upon the occurrence of a
Change of Control if a third party (a) makes the Purchase Offer in the manner,
at the times and otherwise in compliance with the requirements set forth in this
First Supplemental Indenture applicable to a Purchase Offer made by the Company
and (b) purchases all Notes validly tendered and not withdrawn under such
Purchase Offer.

         (c)   If the Company shall be required to commence a Purchase Offer
pursuant to this section, the Company shall follow the procedures specified
below.

               (i)   The Purchase Offer shall remain open for a period of 20
          Business Days following its commencement (the "Offer Period"). No
          later than five Business Days after the termination of the Offer
          Period (the "Purchase Date"), the Company shall purchase the principal
          amount of Notes required to be purchased pursuant to this section (the
          "Offer Amount") or, if less than the Offer Amount has been tendered,
          all Notes tendered in response to the Purchase Offer. Payment for any
          Notes so purchased shall be made in cash and in the same manner as
          interest payments are made.

               (ii)  If the Purchase Date is on or after an interest record date
          and on or before the related Interest Payment Date, any accrued and
          unpaid interest shall be paid to the Person in whose name a Note is
          registered at the close of business on such record date, and no
          additional interest shall be payable to Holders who tender Notes
          pursuant to the Purchase Offer.

               (iii) Within 30 days following the Change of Control Date, the
          Company shall send, by first class mail, a notice of such event to
          each of the Holders, with a copy to the Trustee. The date of delivery
          to the Holders of the notice shall be the date of commencement of the
          Offer Period and the notice shall contain all instructions and
          materials necessary to enable such Holders to tender Notes pursuant to
          the Purchase Offer. The Purchase Offer shall be made to all Holders.
          The notice, which shall govern the terms of the Purchase Offer, shall
          state:

                     (1) that a Change of Control has occurred and that such
          Holder has the right to require the Company to purchase such Holder's
          Notes at a purchase price in cash equal to 101% of the aggregate
          principal amount thereof then outstanding plus



                                     - 11 -
<PAGE>

          accrued but unpaid interest, if any, to the date of purchase of such
          Notes (subject to the right of Holders of record on the relevant
          record date to receive interest on the relevant Interest Payment
          Date);

                     (2) the circumstances and relevant facts regarding such
          Change of Control;

                     (3) that the Purchase Offer is being made pursuant to this
          Section 4.5 and the length of time the Purchase Offer shall remain
          open;

                     (4) the Offer Amount, the purchase price and the Purchase
          Date;

                     (5) that any Note not tendered or accepted for payment
          shall continue to accrue interest;

                     (6) that, unless the Company defaults in making such
          payment, any Note accepted for payment pursuant to the Purchase Offer
          shall cease to accrue interest after the Purchase Date;

                     (7) that Holders electing to have a Note purchased pursuant
          to any Purchase Offer shall be required to surrender the Note, with
          the form entitled "Option of Holder to Elect Purchase" on the reverse
          of the Note duly completed, or transfer by book-entry transfer, to the
          Company, a depository, if appointed by the Company, or a Paying Agent
          at the address specified in the notice prior to the expiration of the
          Offer Period;

                     (8) that Holders shall be entitled to withdraw their
          election if the Company, the Depository or the Paying Agent, as the
          case may be, receives, not later than the expiration of the Offer
          Period, a facsimile transmission or letter setting forth the name of
          the Holder, the principal amount of the Notes the Holder delivered for
          purchase, the certificate number (in the case of a certificated Note)
          and a statement that such Holder is withdrawing his election to have
          such Note purchased; and

                     (9) that Holders whose Notes were purchased only in part,
          if any, shall be issued new Notes equal in principal amount to the
          unpurchased portion of the Notes surrendered (or transferred by
          book-entry transfer).

                  On or before 10:00 a.m. (New York City time) on each Purchase
Date, the Company shall irrevocably deposit with the Trustee or Paying Agent in
immediately available funds the aggregate purchase price with respect to a
principal amount of Notes equal to the Offer Amount, together with accrued and
unpaid interest thereon (to the extent then required to be paid), to be held for
payment in accordance with the terms of this section. On the Purchase Date, the
Company shall, to the extent lawful,

               (i)   accept for payment the Notes tendered pursuant to the
          Purchase Offer,



                                     - 12 -
<PAGE>


               (ii)  deliver or cause the Paying Agent or Depository, as the
          case may be, to deliver to the Trustee Notes so accepted, and

               (iii) deliver to the Trustee an Officers' Certificate stating
          that such Notes were accepted for payment by the Company in accordance
          with the terms of this section.

The Company, the Depository or the Paying Agent, as the case may be, shall
promptly (but in any case not later than three Business Days after the Purchase
Date) mail or deliver to each tendering Holder an amount equal to the purchase
price of the Notes tendered by such Holder and accepted by the Company for
purchase, plus any accrued and unpaid interest thereon, and the Company shall
promptly issue a new Note, and the Trustee shall authenticate and mail or
deliver such new Note to such Holder, equal in principal amount to any
unpurchased portion of such Holder's Notes surrendered. Any Note not so accepted
shall be promptly mailed or delivered by the Company to the Holder thereof.

     SECTION 4.6. Transactions with Affiliates.

         The Company shall not, and shall not permit any of its PGS Subsidiaries
to, enter into any transaction, including, without limitation any contract,
agreement or understanding, with any Affiliate (each of the foregoing, an
"Affiliate Transaction"), unless

               (i)  such Affiliate Transaction is a bona fide business
          transaction reasonably related to the business of the Company or such
          PGS Subsidiary and

               (ii) such Affiliate Transaction is on terms that are no less
          favorable to the Company or such PGS Subsidiary than those that could
          have been obtained at the time of such transaction in a comparable
          transaction by the Company or such PGS Subsidiary with an unrelated
          Person; provided that the following shall not be deemed Affiliate
          Transactions:

                    (a)  prepaid expenses and loans or advances to employees and
similar items in the ordinary course of business;

                    (b)  purchases (and sales) of inventory and services in the
ordinary course of business on terms that are customary in the industry or
consistent with past practices;

                    (c) fees, compensation or employee benefit arrangements
(including any grants of securities under employee benefit or option plans) paid
to, and indemnity provided on behalf of, directors, officers or employees of the
Company or such PGS Subsidiary in the ordinary course consistent with past
practices;

                    (d) transactions pursuant to agreements in effect on the
Issue Date, including amendments thereto after the Issue Date, provided that the
terms of such amendment are not, in the aggregate, less favorable to the Company
than the terms of such agreement prior to such amendment;



                                     - 13 -
<PAGE>

                    (e) any employment agreement (including customary benefits
thereunder) entered into by the Company in the ordinary course of business and
consistent with the current market practice or the past practice of the Company
or such PGS Subsidiary;

                    (f) dividend payments and other distributions permitted
under Section 4.13;

                    (g) the sale to an Affiliate of the Company of Common Equity
of the Company;

                    (h) transactions between the Company and its PGS
Subsidiaries or between PGS Subsidiaries of the Company; and

                    (i) the transactions contemplated by the Restructuring.

     SECTION 4.7. Change of Business.

         The Company shall ensure that the Group shall not substantially change
the general nature of its business, taken as a whole, from its business as of
the Issue Date (it being understood that the Group is engaged in the oil and
oilfield services industry).

     SECTION 4.8. Insurance.

         Each Obligor shall, and the Company shall cause each of its PGS
Subsidiaries which is not an Obligor to, maintain insurance on and in relation
to its properties and business with reputable underwriters or insurance
companies with respect to the risks, and to the extent, customary for companies
engaged in businesses similar to that of the Obligors. The Obligors shall
fulfill their obligations under this Section 4.8 if they arrange insurance
through a captive insurance company for the Group, on terms customary for
companies engaged in businesses similar to that of the Obligors.

     SECTION 4.9. Ranking.

         Each Obligor shall cause the Notes to rank at all times at least pari
passu in right of payment with the Term Loan Facility and all other present and
future unsecured and unsubordinated Financial Indebtedness of such Obligor,
except for Financial Indebtedness which ranks senior to the Notes by operation
of law.

     SECTION 4.10. Group and PGS Subsidiary Indebtedness.

         (a) The Company shall ensure that no member of the Group incurs any
Financial Indebtedness after the Issue Date if after giving effect to the
incurrence thereof the ratio of Adjusted Total Debt to EBITDA is equal to or
greater than 3.75 to 1.

         (b) The Company shall ensure that no PGS Subsidiary shall incur (or
have owing by it or otherwise be liable for) any Financial Indebtedness other
than Financial Indebtedness:



                                     - 14 -
<PAGE>

                    (i)   existing at the Issue Date;

                    (ii)  owed by a PGS Subsidiary of the Company which is not
          an Obligor to any other PGS Subsidiary of the Company which is an
          Obligor;

                    (iii) owed by an Obligor to any other Obligor;

                    (iv)  under the Notes or the Term Loan Facility;

                    (v)   under the Working Capital Facility or the Bonding
          Facility; or

                    (vi)  incurred to refinance any of the Financial
          Indebtedness set out in paragraphs (i) to (v) above provided that
          except with the prior written consent of the Trustee, as directed by
          holders of a majority of the outstanding principal of the Notes, the
          principal amount of such Financial Indebtedness may not be increased,

and any other Financial Indebtedness not included in paragraphs (i) to (vi)
above which does not, at any time, exceed 10% of Total Debt.

          (c) The Company shall ensure that at no time will Total Debt exceed
US$1,500,000,000 (or its equivalent in any other currency or currencies).

     SECTION 4.11.  Project Finance.

                  Each Obligor shall not, and the Company shall cause each of
the PGS Subsidiaries which is not an Obligor not to, invest in or extend any
loans or any other form of credit or grant any guarantee or indemnity to, or for
the benefit of, any Project Company or a Project or otherwise voluntarily assume
any liability, whether actual or contingent, in respect of any obligation of any
Project Company or Project; provided that such investment, loans, credit
guarantee, indemnity or other liability shall be permitted in an amount not to
exceed the sum of:

                    (i)   the proceeds from any issuance of equity securities
          made by the Company after Issue Date (which, for the avoidance of
          doubt, shall not include the securities of the Company issued in
          connection with the Restructuring); plus

                   (ii)   50% of the accumulated Consolidated Net Income of the
          Group on an after tax basis for each fiscal year beginning with the
          fiscal year ended December 31, 2004 less any dividends declared by the
          Company during the period of accumulation; plus

                   (iii)  until the earlier of (a) the third anniversary of the
          Issue Date, or (b) repayment in full of the Senior Notes due 2006,
          US$100,000,000 and after and including that date, an amount of
          US$200,000,000 in aggregate.

     SECTION 4.12.  Environmental Laws.

                  Each Obligor shall, and the Company shall cause each Material
Subsidiary to:



                                     - 15 -
<PAGE>

         (a)    obtain all requisite material Environmental Licenses and (i)
comply in all material respects with such Environmental Licenses and (ii) comply
in all material respects with all other applicable Environmental Laws, in each
case to the extent a failure to do so could reasonably be expected individually
or in the aggregate to have a Material Adverse Effect; and

         (b)    promptly upon receipt of the same, notify the Trustee of, and
comply with the requirements of, any claim, or notice served on it by any
relevant authority or court in respect of any breach or alleged breach of or
corrective or remedial obligation or liability under any Environmental Law
which, if substantiated, would reasonably be expected to have a Material Adverse
Effect.

     SECTION 4.13. Payment of Dividends by the Company.

         (a)    The Company shall not:

                (i)   declare, recommend, make or pay any dividends or other
     distributions or similar payments (including by way of redemption,
     repurchase, defeasance, retirement, return or repayment) (whether in cash
     or in kind) on or in respect of its shares or share capital (or any class
     of its share capital) to any of its shareholders (in their capacity as
     shareholders); or

                (ii)  pay or allow any member of the Group to pay any
     management, advisory or other similar fee to or to the order of the
     shareholders of the Company (in their capacity as shareholders),

in each case, until the earlier of (i) the third anniversary of the Issue Date
and (ii) repayment in full of the Senior Notes Due 2006 issued pursuant to this
First Supplemental Indenture.

                Thereafter, the Company may declare and pay dividends and other
     distributions to its shareholders provided that such dividends and
     distributions can be made in compliance with the laws of Norway and do not
     exceed the sum of:

                (i)   the proceeds from any issuance of equity securities made
     by the Company after the Issue Date (which, for the avoidance of doubt,
     shall not include the securities of the Company issued pursuant to the
     Restructuring), plus

                (ii)  50% of the accumulated Consolidated Net Income of the
     Group for each fiscal year beginning with the fiscal year ended December
     31, 2004 on an after-Tax basis, plus

                (iii) depreciation and amortization expense, less

                (iv)  any dividends or distributions made or declared by the
     Company during the period of accumulation.

         (b)    For the avoidance of doubt, paragraph (a) above shall not
restrict (i) wholly-owned Subsidiaries of the Company declaring or paying
dividends or other distributions




                                     - 16 -
<PAGE>
to their shareholders or (ii) those certain underwriting arrangements made (or
to be made) in respect of securities of the Company issued under the Plan.

     SECTION 4.14. Asset Dispositions.

         The Company shall not, and shall not permit any of its PGS Subsidiaries
to, directly or indirectly enter into a single transaction or a series of
transactions, whether related or not and whether voluntarily or involuntarily,
to sell, lease, convey, transfer or otherwise dispose of any assets (an "Asset
Disposition"), except Asset Dispositions:

         (a)    made for consideration consisting of cash or cash equivalents or
the assumption of Financial Indebtedness of the Company or any PGS Subsidiary in
an aggregate amount equal to the fair market value (evidenced by an Officers'
Certificate and a Board Resolution delivered to the Trustee) and on an arm's
length basis;

         (b)    made to a Material Subsidiary of the Company or to the Company;

         (c)    made in good faith in the ordinary course of business (including
any transfer, conveyance, sale, lease or other disposition of equipment that is
obsolete or no longer used by or useful to the Company);

         (d)    constituting a permitted investment in a Project Company or a
Project under Section 4.11 or a dividend or other distribution permitted under
Section 4.13;

         (e)    constituting a sale of all or substantially all of the assets of
the Company or a Guarantor permitted and made in accordance with Section 5.01
and Section 5.02 of the Original Indenture or a Sale and Leaseback Type
Transaction permitted under Section 4.1 hereof;

         (f)    not permitted by clauses (a) through (e) above, not to exceed
$100,000,000, in the aggregate, since the Issue Date; or

         (g)    approved in writing by the Trustee at the direction of the
Holders of a majority in principal amount of the then outstanding Securities;

provided further, that if the proceeds of such transaction or series of
transactions are deemed to be Major Proceeds, then such proceeds will be applied
in accordance with Section 4.16.

     SECTION 4.15. Major Proceeds.

         The Company shall apply all Major Proceeds, at its sole discretion,
either:

         (a)   to be reinvested in the Group within 12 months of receipt
thereof;
or

         (b)   if not so reinvested, within 12 months, to:

               (i)   purchase participations in the Term Loans;



                                     - 17 -
<PAGE>

               (ii)  purchase Notes in the open market in accordance with
     Section 3.08 of the Original Indenture;

               (iii) commence an offer for the purchase of Notes as set forth in
     Section 4.15(c) hereof;

               (iv)  make voluntary prepayments of the Term Loans; provided that
     such prepayments may not exceed a proportion of such Major Proceeds which
     is equal to the proportion which the Term Loans bear to the aggregate of
     (x) the Term Loans and (y) the face value of the Notes; or

               (v)   both commence an offer for the purchase of the Notes as set
     forth in Section 4.15(c) hereof and make voluntary prepayments of the Term
     Loans where

                     (1)   the proportion of such Major Proceeds to be used to
     fund such offer is equal to the proportion which the Notes bear to the
     aggregate of (i) the Loans and (ii) the face value of the Notes; and

                     (2)   the proportion of such Major Proceeds to be used to
     voluntarily prepay Term Loans is equal to the proportion which the Term
     Loans bear to the aggregate of (i) the Term Loans and (ii) the face value
     of the Senior Notes,

     (c)        If the Company elects to use the Major Proceeds to commence an
offer for the purchase of the Notes, such offer shall be made, to the extent of
the amount of Major Proceeds available for such offer after taking into account
Section 7.5 of the Term Loan Facility which requires repayment of debt
outstanding under that facility, at a price in cash equal to 100% of the
aggregate principal amount thereof to the date of purchase plus accrued but
unpaid interest, if any, to the date of purchase on such Notes. Within 30
Business Days of such election (or such longer period as may be required to
obtain the consent to such offer under the Term Loan Facility), the Company
shall mail a notice to each Holder describing the transaction or transactions
that resulted in the receipt of the Major Proceeds and offering to purchase
Notes on the date specified in such notice, which notice shall substantially
follow the procedures set forth above in Section 4.5(c) with the exception that
(i) the Purchase Offer shall be for the offer price described in the first
sentence of this Section 4.15(c), (ii) the notice shall state that the Purchase
Offer is being made pursuant to this Section 4.15 and (iii) if the aggregate
principal amount of Notes surrendered by Holders exceeds the Offer Amount, the
Company shall select the Notes to be purchased on a pro rata basis (with such
adjustments as may be deemed appropriate by the Company so that only Notes in
denominations of $1.00, or integral multiples thereof, shall be purchased). The
Company shall comply, to the extent applicable, with the requirements of Rule
14e-1 under the Exchange Act and any other securities laws and regulations
thereunder to the extent such laws and regulations are applicable in connection
with the purchase of the Notes pursuant to this Section 4.15. To the extent that
the provisions of any securities laws or regulations conflict with the
provisions of this covenant, the Company shall comply with the applicable
securities laws and shall not be deemed to have breached its obligations under
this covenant by virtue thereof.

     SECTION 4.16.  Rating by Rating Agencies.



                                     - 18 -
<PAGE>

         The Company will use its reasonable best efforts to obtain a rating of
the Notes within 90 days from the Issue Date from Moody's and S&P (or, if
neither Moody's nor S&P shall be rating such obligations, then from another
nationally recognized rating agency).

     SECTION 4.17. Consent for Certain Term Loan Facility Amendments and
Waivers.

         An amendment or waiver that has the effect of changing or which relates
to (i) the definition of "Major Proceeds" in Section 1.2 (Certain Definitions)
of this Supplemental Indenture, (ii) the rate of or the time for payment of
interest on the Notes, (iii) the principal of, any premium on, or the Stated
Maturity of the Notes or (iv) Section 4.5 (Offer to Purchase Upon a Change of
Control) of this First Supplemental Indenture or section 6 of the Notes, or this
Section 4.17, in each case, shall not be made at any time when any amount is
outstanding under (or in respect of) the Term Loan Facility without the prior
written consent of the Agent (as defined in the Term Loan Facility) (acting upon
the instructions of the Majority Lenders (as defined in the Term Loan
Facility)). This Section 4.17 is intended for the benefit of the Finance Parties
(as defined in the Term Loan Facility) and such Finance Parties shall be
entitled to rely on and enforce this Section 4.17 as third-party beneficiaries
of this First Supplemental Indenture solely with respect to the provisions
hereof.

                                   ARTICLE V.
                          ADDITIONAL EVENTS OF DEFAULT

     SECTION 5.1. Additional Events of Default.

         The following Events of Default are hereby added to the Events of
Default with respect to each series of the Notes under Section 6.01 of the
Original Indenture (without regard to any grace periods set forth therein), and
such additional Events of Default apply only to each series of the Notes:

         (a)   any Financial Indebtedness of the Company or any Material
Subsidiary is not paid when due nor within any applicable grace period (as
originally documented or as subsequently amended where such amendment has not
been made in circumstances where an event of default or potential event of
default (however described) exists in respect thereof);

         (b)   any Financial Indebtedness of the Company or any Material
Subsidiary is declared to be or otherwise becomes due and payable prior to its
specified maturity as a result of an event of default (however described);

         (c)   any Lien over assets securing Financial Indebtedness of the
Company or any Material Subsidiary is enforced;

         (d)   no Event of Default will occur under this Section 5.1 (a), (b) or
(c) if the aggregate amount of Financial Indebtedness falling within paragraphs
(a) to (c) above is less than US$20,000,000 (or its equivalent in any other
currency or currencies);

         (e)   a final judgment or order for the payment of money in excess of
$20 million (net of applicable insurance coverage) shall be rendered against the
Company or any Material Subsidiary of the Company and such final judgment or
order shall continue unsatisfied




                                     - 19 -
<PAGE>
and unstayed for a period of 30 days or unsatisfied for a period of 30 days
after the expiration of such stay;

         (f)   any Obligor fails to comply with the covenants set forth in
Clauses 20.3 through 20.12 of the Term Loan Facility and (i) such failure
constitutes an event of default under the Term Loan Facility which has not been
cured or waived by the appropriate lenders under the Term Loan Facility and (ii)
the agent or any of the lenders under the Term Loan Facility shall have (A)
accelerated the obligations under the Term Loan Facility, (B) commenced
enforcement of their rights and remedies in respect of the obligations under the
Term Loan Facility, or (C) taken any other action against any Obligor to improve
their position as creditors of such Obligor (it being understood that none of a
meeting among lenders to discuss options and alternatives, the mere sending of a
notice of default or reservation of rights or the charging of a customary work
fee shall constitute such an action); or

         (g)   any amendment or waiver without the consent of the Holders of at
least a majority of in principal amount of the then outstanding Notes, to the
Term Loan Facility in breach of Clause 33.2(c) thereof.

     SECTION 5.2. Change to Events of Default in Original Indenture.

         The following Event of Default is hereby substituted in its entirety
for and in lieu of clause (2) of Section 6.01 of the Original Indenture with
respect to the Notes, and the following Event of Default applies only to the
Notes:

         (2)   there is a default in the payment of (A) the principal of any
         Security of that series at its Maturity or (B) premium (if any) on any
         Security of that series when the same becomes due and payable;
         provided, that if such default is caused by technical or
         administrative delays in the transmission of funds as certified to the
         Trustee in an Officers' Certificate, such default continues for a
         period of 30 days;

                                  ARTICLE VI.
                            MISCELLANEOUS PROVISIONS

     SECTION 6.1. Table of Contents, Headings, etc.

         The table of contents and headings of the Articles and Sections of this
First Supplemental Indenture have been inserted for convenience of reference
only, are not to be considered a part hereof and shall in no way modify or
restrict any of the terms or provisions hereof.

     SECTION 6.2. Counterpart Originals.

         The parties may sign any number of copies of this First Supplemental
Indenture. Each signed copy shall be an original, but all of them together
represent the same agreement.

     SECTION 6.3. Governing Law.



                                     - 20 -
<PAGE>

         THIS FIRST SUPPLEMENTAL INDENTURE AND THE NOTES OF EACH SERIES SHALL BE
GOVERNED BY AND CONSTRUED IN ACCORDANCE WITH THE LAWS OF THE STATE OF NEW YORK,
WITHOUT REGARD TO PRINCIPLES OF CONFLICTS OF LAW.

     SECTION 6.4. The Trustee.

         The Trustee shall not be responsible in any manner whatsoever for or in
respect of the validity or sufficiency of this First Supplemental Indenture or
for or in respect of the recitals contained herein, all of which are made solely
by the Company and the Guarantors.




                                     - 21 -
<PAGE>


         IN WITNESS WHEREOF, the parties hereto have caused this First
Supplemental Indenture to be duly executed as of the day and year first above
written.

                                    PETROLEUM GEO-SERVICES ASA


                                    By:  /s/ Sam R. Morrow
                                         ---------------------------------------
                                          Name: Sam R. Morrow
                                          Title: SVP - Finance and Treasurer


                                    By:  /s/ Knut Oversjoen
                                         ---------------------------------------
                                          Name: Knut Oversjoen
                                          Title: CFO


                                    GUARANTORS:

                                    MULTIKLIENT INVEST AS

                                    By:  /s/ Knut Oversjoen
                                         ---------------------------------------
                                          Name: Knut Oversjoen
                                          Title: Director


                                    PGS EXPLORATION (UK) LTD.


                                    By:  /s/ Knut Oversjoen
                                         ---------------------------------------
                                          Name: Knut Oversjoen
                                          Title: Director


                                    PGS GEOPHYSICAL AS


                                    By:  /s/ Knut Oversjoen
                                         ---------------------------------------
                                          Name: Knut Oversjoen
                                          Title: Director





                                     - 22 -
<PAGE>



                                 PGS SHIPPING (IOM) LIMITED


                                 By:  /s/ Alexander Holst
                                      ------------------------------------------
                                      Name:  Alexander Holst
                                      Title: Director


                                 PGS RIO BONITO SA


                                 By:  /s/ Alexander Holst   /s/ Svein Knudsen
                                      ------------------------------------------
                                      Name:  Alexander Holst    Svein Knudsen
                                      Title: Attorney-in-fact   Attorney-in-fact


                                 PGS INVESTIGACAO PETROLIFERA LTD.


                                 By:  /s/ Alexander Holst
                                      ------------------------------------------
                                      Name:  Alexander Holst
                                      Title: Attorney-in-fact


                                 PGS ONSHORE, INC.


                                 By:  /s/ Knut Oversjoen
                                      ------------------------------------------
                                      Name:  Knut Oversjoen
                                      Title: Director

                                 LAW DEBENTURE TRUST COMPANY OF NEW YORK, as
                                 Trustee


                                 By:  /s/ Patrick J. Healy
                                      ------------------------------------------
                                      Name:  Patrick J. Healy
                                      Title: Vice President




                                     - 23 -
<PAGE>

                                    EXHIBIT A

         [Unless and until it is exchanged in whole or in part for Notes in
definitive form, this Note may not be transferred except as a whole by the
Depositary to a nominee of the Depositary or by a nominee of the Depositary to
the Depositary or another nominee of the Depositary or by the Depositary or any
such nominee to a successor Depositary or a nominee of such successor
Depositary. The Depository Trust Company ("DTC") shall act as the Depositary
until a successor shall be appointed by the Company and the Registrar. Unless
this certificate is presented by an authorized representative of DTC (55 Water
Street, New York, New York), to the Company or its agent for registration of
transfer, exchange or payment, and any certificate issued is registered in the
name of Cede & Co. or such other name as may be requested by an authorized
representative of DTC (and any payment is made to Cede & Co. or such other
entity as may be requested by an authorized representative of DTC), ANY
TRANSFER, PLEDGE OR OTHER USE HEREOF FOR VALUE OR OTHERWISE BY OR TO ANY PERSON
IS WRONGFUL inasmuch as the registered owner hereof, Cede & Co., has an interest
herein.]*

                                 [FACE OF NOTE]

THIS NOTE HAS NOT BEEN REGISTERED UNDER THE UNITED STATES SECURITIES ACT OF
1933, AS AMENDED (THE "SECURITIES ACT"), AND THIS NOTE MAY NOT BE OFFERED, SOLD,
PLEDGED OR OTHERWISE TRANSFERRED EXCEPT PURSUANT TO AN EFFECTIVE REGISTRATION
STATEMENT OR IN ACCORDANCE WITH AN APPLICABLE EXEMPTION FROM THE REGISTRATION
REQUIREMENTS OF THE SECURITIES ACT AND IN ACCORDANCE WITH ANY APPLICABLE
SECURITIES LAWS OF ANY STATE OF THE UNITED STATES OR ANY OTHER JURISDICTION.

                           PETROLEUM GEO-SERVICES ASA

                [10% SENIOR NOTE DUE 2010 CUSIP NO. 716599 AB 1]

                 [8% SENIOR NOTE DUE 2006 CUSIP NO. 716599 AA 3]

             No. ________      $____________

         Petroleum Geo-Services ASA, a Norwegian public limited liability
company (the "Company"), which term includes any successor Person under the
Indenture hereinafter referred to), for value received, promises to pay to Cede
& Co. or registered assigns the principal sum of ____________________ Million
Dollars [or such lesser amount as indicated in the Schedule of Exchanges of
Definitive Notes],* on November 5, [2010] [2006].

         Interest Payment Dates: June 30 and December 30

         Record Dates: June 15 and December 15

         Reference is hereby made to the further provisions of this Note set
forth on the reverse hereof, which further provisions shall for all purposes
have the same effect as if set forth at this place.

------------------
* To be included in Global Note



<PAGE>




                  IN WITNESS WHEREOF, the Company has caused this Note to be
signed manually or by facsimile by its duly authorized officers.

Dated:
                                     PETROLEUM GEO-SERVICES ASA

                                     By:
                                        ----------------------------------------

                                     Name:
                                     Title:

                                     By:
                                        ----------------------------------------

                                     Name:
                                     Title:

                                     GUARANTORS:

                                     MULTIKLIENT INVEST AS


                                     By:
                                          --------------------------------------
                                           Name:
                                           Title:


                                     PGS EXPLORATION (UK) LTD.


                                     By:
                                          --------------------------------------
                                           Name:
                                           Title:


                                     PGS GEOPHYSICAL AS


                                     By:
                                          --------------------------------------
                                           Name:
                                           Title:


<PAGE>



                                     PGS SHIPPING (IOM) LTD.


                                     By:
                                          --------------------------------------
                                           Name:
                                           Title:


                                     PGS RIO BONITO SA


                                     By:
                                          --------------------------------------
                                           Name:
                                           Title:


                                     PGS INVESTIGACAO PETROLIFERA LTD.


                                     By:
                                          --------------------------------------
                                           Name:
                                           Title:


                                     PGS ONSHORE, INC.


                                     By:
                                          --------------------------------------
                                           Name:
                                           Title:

Certificate of Authentication:

Law Debenture Trust Company of New York
as Trustee, certifies that this is one
of the Notes referred to in the
within-mentioned Indenture.

By:
   -----------------------------------
Authorized Signatory




<PAGE>


                                [REVERSE OF NOTE]

                           PETROLEUM GEO-SERVICES ASA

                           [10% SENIOR NOTE DUE 2010]
                            [8% SENIOR NOTE DUE 2006]

         This Note is one of a duly authorized issue of [10% Senior Notes due
2010] [8% Senior Notes due 2006] (the "Notes") of Petroleum Geo-Services ASA, a
Norwegian public limited liability company (the "Company"). The Company issued
the Notes under an Indenture dated as of November 5, 2003 (the "Original
Indenture") between the Company, the Guarantors and the Trustee, as supplemented
by the First Supplemental Indenture thereto dated as of November 5, 2003 (the
"Supplemental Indenture" and the Original Indenture as so supplemented, the
"Indenture") between the Company, the Guarantors and the Trustee. The terms of
the Notes include those stated in the Indenture and those made part of the
Indenture by reference to the Trust Indenture Act of 1939, as amended (15 U.S.
Code Sections 77aaa-77bbbb) (the "TIA"), as in effect on the date of execution
of the Indenture. The Notes are subject to all such terms, and Holders are
referred to the Indenture and the TIA for a statement of such terms and for the
definitions of capitalized terms used but not defined herein. The Notes are
unsecured general obligations of the Company limited to [Seven Hundred Forty
Five Million Nine Hundred Forty Eight Thousand Eight Hundred Ten Dollars] [Two
Hundred Fifty Million Dollars] in aggregate principal amount. The Original
Indenture provides for the issuance of other series of debt securities
(including the Notes, the "Debt Securities") thereunder.

         1.     Interest. The Company promises to pay interest on the principal
amount of this Note at [10%][8%] per annum from its Issue Date until maturity.
The Company will pay interest semiannually on June 30 and December 30 of each
year (each an "Interest Payment Date"), and at maturity, or if any such day is
not a Business Day, on the next succeeding Business Day. Interest on the Notes
will accrue from the most recent Interest Payment Date on which interest has
been paid or, if no interest has been paid, from the Issue Date for the Notes;
provided that if there is no existing Default in the payment of interest, and if
this Note is authenticated between June 15 or December 15 next preceding each
Interest Payment Date (each, a "Record Date") and such Interest Payment Date,
interest shall accrue from such next succeeding Interest Payment Date; provided
further, that the first Interest Payment Date shall be December 30, 2003. Upon
the expiration of any cure period, the Company shall pay interest on overdue
principal and premium (if any) from time to time on demand at a default rate
equal to 2% per annum in excess of the interest rate then in effect; it shall
pay interest on overdue installments of interest (without regard to any
applicable grace periods) from time to time to Holders as of a special record
date set by the Trustee on instructions from the Company at the same rate to the
extent lawful. Interest will be computed on the basis of a 360-day year
consisting of twelve 30-day months.

         2.     Method of Payment. The Company will pay interest on the Notes
(except defaulted interest) to the Persons who are registered Holders of Notes
at the close of business on the Record Date next preceding the Interest Payment
Date, even if such Notes are canceled after such Record Date and on or before
such Interest Payment Date, or in the case of interest payable at maturity, to
the Persons to whom principal is paid at maturity. The Holder must surrender
this Note to a Paying Agent to collect principal payments. The Company will pay
the principal of



<PAGE>

and premium (if any) and interest on the Notes in money of the United States of
America that at the time of payment is legal tender for payment of public and
private debts. The Company, however, may pay such amounts (i) by wire transfer
with respect to Notes held in book-entry form or (ii) by check payable in such
money mailed to a Holder's registered address with respect to any Notes.

         3.     Ranking. The Notes are senior unsecured obligations of the
Company and rank pari passu with all other unsecured and unsubordinated
indebtedness of the Company.

         4.     Optional Redemption.

[FOR NOTES DUE 2010:] [The Notes shall not be redeemable at the Company's option
prior to November 5, 2007. Thereafter, the Notes shall be redeemable at the
option of the Company, in whole or in part, at any time upon not less than 30
nor more than 60 days' notice, at the redemption prices (expressed as
percentages of principal amount) set forth below plus accrued and unpaid
interest, if any, to the applicable redemption date, if redeemed during the
twelve-month period beginning on November 5 of the years indicated below:

<TABLE>
<CAPTION>
                        YEAR                               PERCENTAGE
                        ----                               ----------

<S>                     <C>                                 <C>
                        2007                                105.00%
                        2008                                103.33%
                        2009                                101.67%]

</TABLE>

              [FOR NOTES DUE 2006:] [The Notes shall be redeemable at the option
of the Company, in whole or in part, at any time upon not less than 30 nor more
than 60 days' notice, at the redemption prices (expressed as percentages of
principal amount) set forth below plus accrued and unpaid interest, if any, to
the applicable redemption date, if redeemed during the twelve-month period
beginning on November 5 of the years indicated below:

<TABLE>
<CAPTION>
                        YEAR                               PERCENTAGE
                        ----                               ----------

<S>                     <C>                                <C>
                        2003                               103.00%
                        2004                               102.00%
                        2005                               101.00%]

</TABLE>

         5.     Guarantee.

         The Notes are entitled to the benefits of the Guarantee under Article X
of the Original Indenture and any other covenants and undertakings of the
Guarantors under the Indenture.

         6.     Purchase at Option of Holder.

         (a)    If there shall at any time or times occur a Change of Control
(the date of the last event required for a Change of Control to be effected
hereinafter referred to as the "Change of Control Date"), then the Company shall
make an offer to purchase (the "Purchase Offer"), all Notes then outstanding at
an offer price in cash equal to 101% of the principal



<PAGE>

amount thereof outstanding, plus accrued and unpaid interest, if any, to the
date of purchase of the Notes. Within 30 days following the Change of Control
Date, the Company shall notify the Holders in writing, with a copy to the
Trustee, of the occurrence of a Change of Control and that the Company is making
a Purchase Offer. The notice shall contain all instructions and materials
necessary to enable such Holders to tender Notes pursuant to the Purchase Offer,
pursuant to the procedures required by the Indenture and shall otherwise comply
with the requirements of Section 4.5 of the Supplemental Indenture. The Purchase
Offer shall remain open for a period of at least 20 Business Days following its
commencement (the "Offer Period") and the Company shall consummate the purchase
of all Notes tendered pursuant to the Purchase Offer and not withdrawn prior to
the expiration of the Offer Period not later than five Business Days after the
termination of the Offer Period.

         (b)    Pursuant to Section 4.5 of the Supplemental Indenture, Holders
of Notes that are the subject of a Purchase Offer will receive a Purchase Offer
from the Company upon commencement of any Offer Period and may elect to have
such Notes purchased by completing the form titled "Option of Holder to Elect
Purchase" appearing below.

         (c)    If at any time or times the Company elects to use Major Proceeds
to commence a tender offer in respect of the Notes, such offer shall be made, to
the extent of the amount of Major Proceeds available after taking into account
the provisions of the Term Loan Facility that require repayment of Term Loans,
at an offer price in cash equal to 100% of the principal amount thereof
outstanding, plus accrued and unpaid interest, if any, to the date of purchase
of the Notes. The procedures for purchase of the Notes shall be substantially
identical to the procedures for Purchase Offers described above relating to a
Change of Control, except as otherwise set forth in Section 4.16 of the
Supplemental Indenture; provided that no Holder shall be required to tender the
Notes in connection with such offer.

         7.     Paying Agent and Registrar. Initially, Law Debenture Trust
Company of New York (the "Trustee"), the Trustee under the Indenture, will act
as Principal Paying Agent and Registrar. The Company may change any Principal
Paying Agent, Registrar, co-registrar or additional paying agent without notice
to any Holder. The Company may act in any such capacity.

         8.     Denominations, Transfer, Exchange. The Notes are in registered
form without coupons in denominations of $1.00 and integral multiples of $1.00.
The transfer of Notes may be registered and Notes may be exchanged as provided
in the Indenture. The Registrar and the Trustee may require a Holder, among
other things, to furnish appropriate endorsements and transfer documents and to
pay any taxes and fees required by law or permitted by the Indenture. The
Registrar shall not be required to exchange or register the transfer of any
Notes during the period between a record date and the corresponding Interest
Payment Date, nor shall the Registrar be required to register the transfer or
exchange of (a) any Note selected for redemption in whole or in part, except the
unredeemed portion of any Note being redeemed in part, or (b) any Note during
the period beginning 15 days before the mailing of notice of redemption of Notes
to be redeemed and ending at the close of business on the date of mailing.

         9.     Persons Deemed Owners. The registered Holder of a Note
identified in the registry maintained by the Registrar shall be treated as its
owner for all purposes.


<PAGE>

         10.    Amendments and Waivers. Subject to certain exceptions and
limitations, (a) the Notes may be amended or supplemented with the consent of
the Holders of at least a majority in principal amount of the then outstanding
Notes, (b) the Indenture may be amended or supplemented with the consent of the
Holders of at least a majority in principal amount of the then outstanding Debt
Securities of all series affected by such amendment or supplement (acting as one
class), and (c) compliance by the Company with any provision of the Indenture
with respect to the Notes (other than any continuing Default or Event of Default
in the payment of the principal of or premium (if any) or interest on the Notes)
may be waived by the Holders of at least a majority in principal amount of the
Notes then outstanding in accordance with the terms of the Indenture. Without
the consent of any Holder, the Company, the Guarantors and the Trustee may amend
or supplement the Notes or the Indenture with respect to the Notes (i) to cure
any ambiguity, omission, defect or inconsistency; (ii) to provide for the
assumption of the obligations of the Company under the Indenture to Holders in
the case of the merger, consolidation or sale, lease, conveyance, transfer or
other disposition of all or substantially all of the assets of the Company;
(iii) to provide for uncertificated Notes in addition to or in place of
certificated Notes, or to provide for the issuance of bearer Notes (with or
without coupons); (iv) to provide any security for, to add any guarantees of or
to provide additional Obligors on, the Notes; (v) to comply with any requirement
in order to effect or maintain the qualification of the Indenture under the TIA;
(vi) to add to the covenants of the Company or any Guarantor for the benefit of
the Holders of Notes, or to surrender any right or power conferred upon the
Company or any Guarantor pursuant to the Indenture; (vii) to add any additional
Events of Default with respect to the Notes; (viii) to change or eliminate any
of the provisions of the Indenture, provided that any such change or elimination
shall become effective only when there is no outstanding Debt Security of any
series created prior to the execution of such amendment or supplemental
indenture that is adversely affected in any material respect by such change in
or elimination of such provision; (ix) to supplement any of the provisions of
the Indenture to such extent as shall be necessary to permit or facilitate the
defeasance and discharge of the Notes; provided, however, that any such action
shall not, as evidenced by an Officers' Certificate, delivered to the Trustee,
adversely affect the interest of the Holders of Notes or any other series of
Debt Securities in any material respect; or (x) to evidence and provide for the
acceptance of appointment hereunder by a successor Trustee with respect to the
Notes and to add to or change any of the provisions of the Indenture as shall be
necessary to provide for or facilitate the administration of the trusts
thereunder by more than one Trustee, pursuant to the requirements of the
Indenture.

         The right of any Holder to participate in any consent required or
sought pursuant to any provision of the Indenture (and the obligation of the
Company to obtain any such consent otherwise required from such Holder) may be
subject to the requirement that such Holder shall have been the Holder of record
of any Notes with respect to which such consent is required or sought as of a
date identified by the Trustee in a notice furnished to Holders in accordance
with the terms of the Indenture.

         Without the consent of each Holder affected, the Company may not (i)
reduce the percentage or principal amount of Notes whose Holders must consent to
an amendment, supplement or waiver of or under the Indenture or the Notes; (ii)
reduce the rate of or change the time for payment of interest, including default
interest, on any Note; (iii) reduce the principal of or premium on, or change
the Stated Maturity of, any Note; (iv) reduce the premium, if any,



<PAGE>

payable upon the redemption of any Note or change the time at which any Note may
or shall be redeemed; (v) change the coin or currency or currencies in which any
Note or any premium or interest thereon is payable; (vi) impair the right to
institute suit for the enforcement of any payment of principal of or premium (if
any) or interest on any Note; (vii) make any change in the percentage of
principal amount of Notes necessary to waive compliance with certain provisions
of the Indenture or (viii) waive a continuing Default or Event of Default in the
payment of principal of or premium (if any) or interest on the Notes; or (ix)
change the definition of Notes deemed outstanding pursuant to Section 2.10 of
the Original Indenture.

         A supplemental indenture that changes or eliminates any covenant or
other provision of the Indenture that has expressly been included solely for the
benefit of one or more particular series of Debt Securities, or that modifies
the rights of the Holders of Debt Securities of such series with respect to such
covenant or other provision, shall be deemed not to affect the rights under the
Indenture of the Holders of Debt Securities of any other series.

         11.    Defaults and Remedies. Events of Default are defined in the
Indenture (the provisions of which, notwithstanding any inconsistency with the
below, shall govern the determination of the occurrence of a Default or Event of
Default and the remedies available to Holders of Notes upon the occurrence of an
Event of Default) and generally include: (i) default for 30 days in payment of
any interest on the Notes; (ii) default in any payment of principal of or
premium (if any) on the Notes at maturity; provided that if such default is
caused by technical or administrative delays in the transmission of funds (as
certified to the Trustee in the Officers' Certificate), such default continues
for a period of 30 days; (iii) default by the Company or any Guarantor in
compliance with any of its other covenants or agreements in, or provisions of,
the Notes or in the Indenture which shall not have been remedied within 90 days
after written notice by the Trustee or by the holders of at least 25% in
principal amount of the Notes then outstanding (or, in the event that other Debt
Securities issued under the Indenture are also affected by the default, then 25%
in principal amount of the outstanding Debt Securities so affected); (iv) any
Financial Indebtedness (other than the Notes) of the Company or any Material
Subsidiary having an outstanding principal amount of $20 million or more,
individually or in the aggregate is accelerated or not paid when due or any Lien
securing such Financial Indebtedness is enforced; (v) a judgment or order for
the payment of money in excess of $20 million (net of applicable insurance
coverage) having been rendered against the Company or any Material Subsidiary of
the Company and such judgment or order shall continue unsatisfied and unstayed
for a period of 30 days or unsatisfied for a period of 30 days after the
expiration of such stay; (vi) subject to certain conditions, the failure by the
Company and the Guarantors to comply with certain covenants in the Term Loan
Facility, if such failure constitutes an event of default under the Term Loan
Facility which has not been cured or waived; and (vii) certain events involving
bankruptcy, insolvency or reorganization of the Company or any Material
Subsidiary. If an Event of Default with respect to the Notes occurs and is
continuing, the Trustee or the Holders of at least 25% in principal amount of
the then outstanding Notes may declare the principal of and interest on the
Notes to be immediately due and payable, except that in the case of an Event of
Default arising from certain events of bankruptcy, insolvency or reorganization
of the Company or any Material Subsidiary, all outstanding Debt Securities under
the Indenture become due and payable immediately without further action or
notice. The amount due and payable upon the acceleration of any Note is equal to
100% of the principal amount thereof plus accrued interest to the date of
payment. Holders may not enforce the Indenture or the Notes except as provided
in


<PAGE>

the Indenture. The Trustee may require indemnity reasonably satisfactory to it
before it enforces the Indenture or the Notes. Subject to certain limitations,
Holders of a majority in principal amount of the then outstanding Notes may
direct the Trustee in its exercise of any trust or power. The Trustee may
withhold from Holders notice of any continuing default (except a default in
payment of principal or interest) if it determines that withholding notice is in
their interests. The Company must furnish an annual compliance certificate to
the Trustee.

         12.    Discharge Prior to Maturity. The Indenture with respect to the
Notes shall be discharged and canceled upon the payment of all of the Notes and
shall be discharged except for certain obligations upon the irrevocable deposit
with the Trustee of funds or U.S. Government Obligations sufficient for such
payment.

         13.    Trustee Dealings with Company. The Trustee, in its individual or
any other capacity, may make loans to, accept deposits from, and perform
services for the Company or its Affiliates, and may otherwise deal with the
Company or its Affiliates, as if it were not Trustee.

         14.    No Recourse Against Others. A director, officer, employee or
stockholder, as such, of the Company or any Guarantor shall not have any
liability for any obligations of the Company or such Guarantor, as the case may
be, under the Notes or the Indenture or for any claim based on, in respect of or
by reason of such obligations or their creation. Each Holder by accepting a Note
waives and releases all such liability. The waiver and release are part of the
consideration for the issuance of the Notes.

         15.    Authentication. This Note shall not be valid until authenticated
by the manual signature of the Trustee or an authenticating agent.

         16.    CUSIP Numbers. Pursuant to a recommendation promulgated by the
Committee on Uniform Security Identification Procedures, the Company has caused
CUSIP numbers to be printed on the Notes as a convenience to the Holders of the
Notes. No representation is made as to the accuracy of such numbers as printed
on the Securities and reliance may be placed only on the other identification
numbers printed thereon.

         17.    Abbreviations. Customary abbreviations may be used in the name
of a Holder or an assignee, such as: TEN COM (= tenants in common), TEN ENT (=
tenants by the entireties), JT TEN (= joint tenants with right of survivorship
and not as tenants in common), CUST (= Custodian), and U/G/M/A (= Uniform Gifts
to Minors Act).

         The Company will furnish to any Holder, upon written request and
without charge, a copy of the Indenture. Request may be made to:

         Petroleum Geo-Services ASA
         Strandveien 4
         N-1366 Lysaker
         Norway
         Attention:  General Counsel and Chief Financial Officer

         or to
<PAGE>



         Petroleum Geo-Services ASA
         738 Highway 6 South, Suite 1000
         Houston, Texas  77079
         Attention:  Treasurer



<PAGE>


                                 ASSIGNMENT FORM

                  To assign this Note, fill in the form below: (I) or (we)
assign and transfer this Security to ___________________________________________
(Insert assignee's social security or tax I.D. number)


--------------------------------------------------------------------------------
--------------------------------------------------------------------------------
--------------------------------------------------------------------------------
              (Print or type assignee's name, address and zip code)

and irrevocably appoint____________________________________________ as agent to
transfer this Note on the books of the Company.  The agent may substitute
another to act for him.


------------------------------------------------------------------------------
Date____________________  Your Signature:_____________________________________
(Sign exactly as your name appears on the face of this Note)

Signature Guarantee:____________________________________________________________
              (Participant in a Recognized Signature Guaranty Medallion Program)



<PAGE>


                       OPTION OF HOLDER TO ELECT PURCHASE

                  If you want to elect to have this Note purchased by the
Company pursuant to the Change of Control provisions of Section 4.5 of the
Supplemental Indenture, check the following box. [ ]

                  If you want to elect to have only part of the Note purchased
by the Company pursuant to the Change of Control provisions of Section 4.5 of
the Supplemental Indenture, state the amount you elect to have purchased:

$
 ------------
Date:               Your Signature:
     -------------               --------------------

--------------------------------------------------------------------------------
                 (Sign exactly as your name appears on the Note)
--------------------------------------------------------------------------------

                  Tax Identification No.:
                                         ------

                  Signature Guarantee.*

- Signature must be guaranteed by an eligible guarantor institution within the
meaning of Securities and Exchange Commission Rule 17Ad-15 (including banks,
stock brokers, savings and loan associations, national securities exchanges,
registered securities associations, clearing agencies and credit unions) with
membership or participation in an approved signature guarantee medallion program
if this Note is to be delivered other than to, and in the name of, the
registered holder.



<PAGE>


                   SCHEDULE OF EXCHANGES OF DEFINITIVE NOTES*

     The following exchanges of a part of this Global Note for Definitive Notes
have been made:

<TABLE>

                                                                           PRINCIPAL AMOUNT
                                AMOUNT OF              AMOUNT OF            OF THIS GLOBAL          SIGNATURE OF
                               DECREASE IN            INCREASE IN           NOTE FOLLOWING       AUTHORIZED OFFICER
                            PRINCIPAL AMOUNT        PRINCIPAL AMOUNT         SUCH DECREASE          OF TRUSTEE OR
    DATE OF EXCHANGE       OF THIS GLOBAL NOTE    OF THIS GLOBAL NOTE        (OR INCREASE)       SECURITY CUSTODIAN
    ----------------       -------------------    -------------------      ---------------       ------------------
<S>                       <C>                     <C>                      <C>                   <C>




</TABLE>










-----------------
* To be included in Global Note.