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                                                                     Exhibit 4.1

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

                                    INDENTURE

                             SPACEHAB, INCORPORATED

                                       to

                       First Union National Bank, Trustee

                   8% Convertible Subordinated Notes due 2007

                          Dated as of October 15, 1997

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

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                                TABLE OF CONTENTS

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                                    ARTICLE I

             DEFINITIONS AND OTHER PROVISIONS OF GENERAL APPLICATION

SECTION 1.01.    DEFINITIONS...................................................1
  Act..........................................................................2
  Additional Interest..........................................................2
  Affiliate....................................................................2
  Agent Member.................................................................2
  Applicable Procedures........................................................2
  Authenticating Agent.........................................................2
  Board of Directors...........................................................2
  Board Resolution.............................................................2
  Business Day.................................................................2
  Change in Control............................................................2
  Closing Price................................................................2
  Commencement Date............................................................3
  Commission...................................................................3
  Common Stock.................................................................3
  Company......................................................................3
  Company Request or Company Order.............................................3
  Corporate Trust Office.......................................................3
  Corporation..................................................................3
  Defaulted Interest...........................................................4
  Definitive Security..........................................................4
  Depositary...................................................................4
  Distribution Date............................................................4
  Dollar or U.S.$..............................................................4
  DTC..........................................................................4
  Event of Default.............................................................4
  Excess Shares................................................................4
  Exchange Act.................................................................4
  Expiration Date..............................................................4
  Expiration Time..............................................................4
  Global Security..............................................................4
  Holder.......................................................................4
  Indenture....................................................................4
  Initial Purchasers...........................................................4
  Institutional Accredited Investor............................................5
  Interest Payment Date........................................................5
  Issue Date...................................................................5
  Maturity.....................................................................5
  Non-Recourse Obligation......................................................5
  Notice of Default............................................................5
  Officers' Certificate........................................................5
  Opinion of Counsel...........................................................5
  Outstanding..................................................................5
  Paying Agent.................................................................6
  Person.......................................................................6
  Predecessor Security.........................................................6
  Purchased Shares.............................................................7

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  Qualified Institutional Buyer................................................7
  Redemption Date..............................................................7
  Redemption Price.............................................................7
  Reference Date...............................................................7
  Registration Default.........................................................7
  Registration Rights Agreement................................................7
  Regular Record Date..........................................................7
  Regulation S.................................................................7
  Repurchase Date..............................................................7
  Repurchase Price.............................................................7
  Responsible Officer..........................................................7
  Restricted Global Security...................................................7
  Restricted Security..........................................................7
  Rule 144A....................................................................7
  Rule 144A Information........................................................7
  Securities...................................................................8
  Securities Act...............................................................8
  Security Register and Security Registrar.....................................8
  Senior Indebtedness..........................................................8
  Shelf Registration Statement.................................................8
  Special Record Date..........................................................8
  Stated Maturity..............................................................8
  Subsidiary...................................................................8
  Surrendered Securities.......................................................9
  Trading Day..................................................................9
  Transfer Restricted Securities...............................................9
  Trust Indenture Act..........................................................9
  Trustee......................................................................9
  United States................................................................9
  U.S. Government Obligation...................................................9
  Vice President...............................................................9
SECTION 1.02.    COMPLIANCE CERTIFICATES AND OPINIONS..........................9
SECTION 1.03.    FORM OF DOCUMENTS DELIVERED TO TRUSTEE.......................10
SECTION 1.04.    ACTS OF HOLDERS; RECORD DATES................................10
SECTION 1.05.    NOTICES, ETC., TO TRUSTEE AND COMPANY........................12
SECTION 1.06.    NOTICE TO HOLDERS; WAIVER....................................13
SECTION 1.07.    CONFLICT WITH TRUST INDENTURE ACT............................13
SECTION 1.08.    EFFECT OF HEADINGS AND TABLE OF CONTENTS.....................13
SECTION 1.09.    SUCCESSORS AND ASSIGNS.......................................13
SECTION 1.10.    SEVERABILITY CLAUSE..........................................13
SECTION 1.11.    BENEFITS OF INDENTURE........................................14
SECTION 1.12.    GOVERNING LAW................................................14
SECTION 1.13.    LEGAL HOLIDAYS...............................................14

                                   ARTICLE II

                                 SECURITY FORMS

SECTION 2.01.    FORMS GENERALLY..............................................14
SECTION 2.02.    FORM OF FACE OF SECURITY.....................................15
SECTION 2.03.    FORM OF REVERSE OF SECURITY..................................19
SECTION 2.04.    FORM OF TRUSTEE'S CERTIFICATE OF AUTHENTICATION..............24
SECTION 2.05.    FORM OF CONVERSION NOTICE....................................24
SECTION 2.06.    FORM OF CERTIFICATION........................................25


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                                   ARTICLE III

                                 THE SECURITIES

SECTION 3.01.    TITLE AND TERMS; ISSUABLE IN SERIES..........................26
SECTION 3.02.    DENOMINATIONS................................................27
SECTION 3.03.    EXECUTION, AUTHENTICATION, DELIVERY AND DATING...............27
SECTION 3.04.    GLOBAL AND NON-GLOBAL SECURITIES.............................28
SECTION 3.05.    REGISTRATION; REGISTRATION OF TRANSFER AND EXCHANGE..........30
SECTION 3.06.    MUTILATED, DESTROYED, LOST AND STOLEN SECURITIES.............34
SECTION 3.07.    PAYMENT OF INTEREST; INTEREST RIGHTS PRESERVED...............34
SECTION 3.08.    PERSONS DEEMED OWNERS........................................36
SECTION 3.09.    CANCELLATION.................................................36
SECTION 3.10.    COMPUTATION OF INTEREST......................................36

                                   ARTICLE IV

                           SATISFACTION AND DISCHARGE

SECTION 4.01.    SATISFACTION AND DISCHARGE OF INDENTURE......................36
SECTION 4.02.    APPLICATION OF TRUST MONEY...................................38

                                    ARTICLE V

                                    REMEDIES

SECTION 5.01.    EVENTS OF DEFAULT............................................38
SECTION 5.02.    ACCELERATION OF MATURITY; RESCISSION AND ANNULMENT...........40
SECTION 5.03.    COLLECTION OF INDEBTEDNESS AND SUITS FOR ENFORCEMENT BY 
                  TRUSTEE ....................................................41
SECTION 5.04.    TRUSTEE MAY FILE PROOFS OF CLAIM.............................41
SECTION 5.05.    TRUSTEE MAY ENFORCE CLAIMS WITHOUT POSSESSION OF SECURITIES..42
SECTION 5.06.    APPLICATION OF MONEY COLLECTED...............................42
SECTION 5.07.    LIMITATION ON SUITS..........................................43
SECTION 5.08.    UNCONDITIONAL RIGHT OF HOLDERS TO RECEIVE PRINCIPAL, 
                  PREMIUM AND INTEREST AND TO CONVERT ........................43
SECTION 5.09.    RESTORATION OF RIGHTS AND REMEDIES...........................43
SECTION 5.10.    RIGHTS AND REMEDIES CUMULATIVE...............................44
SECTION 5.11.    DELAY OR OMISSION NOT WAIVER.................................44
SECTION 5.12.    CONTROL BY HOLDERS...........................................44
SECTION 5.13.    WAIVER OF PAST DEFAULTS......................................44
SECTION 5.14.    UNDERTAKING FOR COSTS........................................45
SECTION 5.15.    WAIVER OF USURY, STAY OR EXTENSION LAWS......................45

                                   ARTICLE VI

                                   THE TRUSTEE

SECTION 6.01.    CERTAIN DUTIES AND RESPONSIBILITIES..........................45
SECTION 6.02.    NOTICE OF DEFAULTS...........................................46
SECTION 6.03.    CERTAIN RIGHTS OF TRUSTEE....................................46
SECTION 6.04.    NOT RESPONSIBLE FOR RECITALS OR ISSUANCE OF SECURITIES.......47
SECTION 6.05.    MAY HOLD SECURITIES..........................................48
SECTION 6.06.    MONEY HELD IN TRUST..........................................48
SECTION 6.07.    COMPENSATION AND REIMBURSEMENT...............................48
SECTION 6.08.    DISQUALIFICATION:  CONFLICTING INTERESTS.....................49
SECTION 6.09.    CORPORATE TRUSTEE REQUIRED; ELIGIBILITY......................49
SECTION 6.10.    RESIGNATION AND REMOVAL; APPOINTMENT OF SUCCESSOR............49
SECTION 6.11.    ACCEPTANCE OF APPOINTMENT BY SUCCESSOR.......................50
SECTION 6.12.    MERGER, CONVERSION, CONSOLIDATION OR SUCCESSION TO BUSINESS..51


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SECTION 6.13.    PREFERENTIAL COLLECTION OF CLAIMS AGAINST COMPANY............51
SECTION 6.14.    APPOINTMENT OF AUTHENTICATING AGENT..........................51
SECTION 6.15.    APPOINTMENT OF CO-TRUSTEE....................................53

                                   ARTICLE VII

                HOLDERS' LISTS AND REPORTS BY TRUSTEE AND COMPANY

SECTION 7.01.    COMPANY TO FURNISH TRUSTEE NAMES AND ADDRESSES OF HOLDERS....53
SECTION 7.02.    PRESERVATION OF INFORMATION; COMMUNICATIONS TO HOLDERS.......54
SECTION 7.03.    REPORTS BY TRUSTEE...........................................54
SECTION 7.04.    REPORTS BY COMPANY...........................................54

                                  ARTICLE VIII

              CONSOLIDATION, MERGER, CONVEYANCE, TRANSFER OR LEASE

SECTION 8.01.    COMPANY MAY CONSOLIDATE, ETC., ONLY ON CERTAIN TERMS.........55
SECTION 8.02.    SUCCESSOR SUBSTITUTED........................................55

                                   ARTICLE IX

                             SUPPLEMENTAL INDENTURES

SECTION 9.01.    SUPPLEMENTAL INDENTURES WITHOUT CONSENT OF HOLDERS...........56
SECTION 9.02.    SUPPLEMENTAL INDENTURES WITH CONSENT OF HOLDERS..............56
SECTION 9.03.    EXECUTION OF SUPPLEMENTAL INDENTURES.........................57
SECTION 9.04.    EFFECT OF SUPPLEMENTAL INDENTURES............................58
SECTION 9.05.    CONFORMITY WITH TRUST INDENTURE ACT..........................58
SECTION 9.06.    REFERENCE IN SECURITIES TO SUPPLEMENTAL INDENTURES...........58

                                    ARTICLE X

                                    COVENANTS

SECTION 10.01.   PAYMENT OF PRINCIPAL, PREMIUM AND INTEREST...................58
SECTION 10.02.   MAINTENANCE OF OFFICE OR AGENCY..............................58
SECTION 10.03.   MONEY FOR SECURITY PAYMENTS TO BE HELD IN TRUST..............59
SECTION 10.04.   STATEMENT BY OFFICERS AS TO DEFAULT..........................60
SECTION 10.05.   EXISTENCE....................................................60
SECTION 10.06.   MAINTENANCE OF PROPERTIES....................................60
SECTION 10.07.   PAYMENT OF TAXES AND OTHER CLAIMS............................61
SECTION 10.08.   WAIVER OF CERTAIN COVENANTS..................................61
SECTION 10.09.   DELIVERY OF CERTAIN INFORMATION..............................61
SECTION 10.10.   RESALE OF CERTAIN SECURITIES; REPORTING ISSUER...............61
SECTION 10.11.   REGISTRATION RIGHTS..........................................62

                                   ARTICLE XI

                            REDEMPTION OF SECURITIES

SECTION 11.01.   RIGHT OF REDEMPTION..........................................63
SECTION 11.02.   APPLICABILITY OF ARTICLE.....................................63
SECTION 11.03.   ELECTION TO REDEEM; NOTICE TO TRUSTEE........................63
SECTION 11.04.   SELECTION BY TRUSTEE OF SECURITIES TO BE REDEEMED............64
SECTION 11.05.   NOTICE OF REDEMPTION.........................................64
SECTION 11.06.   DEPOSIT OF REDEMPTION PRICE..................................65
SECTION 11.07.   SECURITIES PAYABLE ON REDEMPTION DATE........................65
SECTION 11.08.   SECURITIES REDEEMED IN PART..................................65
SECTION 11.09.   CONVERSION ARRANGEMENT ON CALL FOR REDEMPTION................66


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                                   ARTICLE XII

                           SUBORDINATION OF SECURITIES

SECTION 12.01.   SECURITIES SUBORDINATE TO SENIOR INDEBTEDNESS................67
SECTION 12.02.   PAYMENT OVER OF PROCEEDS UPON DISSOLUTION, ETC...............67
SECTION 12.03.   NO PAYMENT WHEN SENIOR INDEBTEDNESS IN DEFAULT...............68
SECTION 12.04.   PAYMENT PERMITTED IF NO DEFAULT..............................68
SECTION 12.05.   SUBROGATION TO RIGHTS OF HOLDERS OF SENIOR INDEBTEDNESS......69
SECTION 12.06.   PROVISIONS SOLELY TO DEFINE RELATIVE RIGHTS..................69
SECTION 12.07.   TRUSTEE TO EFFECTUATE SUBORDINATION..........................69
SECTION 12.08.   NO WAIVER OF SUBORDINATION PROVISIONS........................69
SECTION 12.09.   NOTICE TO TRUSTEE............................................70
SECTION 12.10.   RELIANCE ON JUDICIAL ORDER OR CERTIFICATE OF LIQUIDATING 
                  AGENT ......................................................71
SECTION 12.11.   TRUSTEE NOT FIDUCIARY FOR HOLDERS OF SENIOR INDEBTEDNESS.....71
SECTION 12.12.   RIGHTS OF TRUSTEE AS HOLDER OF SENIOR INDEBTEDNESS;  
                  PRESERVATION OF TRUSTEE'S RIGHTS ...........................71
SECTION 12.13.   ARTICLE APPLICABLE TO PAYING AGENTS..........................71
SECTION 12.14.   CERTAIN CONVERSIONS DEEMED PAYMENT...........................71

                                  ARTICLE XIII

                            CONVERSION OF SECURITIES

SECTION 13.01.   CONVERSION PRIVILEGE AND CONVERSION PRICE....................72
SECTION 13.02.   EXERCISE OF CONVERSION PRIVILEGE.............................73
SECTION 13.03.   FRACTIONS OF SHARES..........................................74
SECTION 13.04.   ADJUSTMENT OF CONVERSION PRICE...............................74
SECTION 13.05.   NOTICE OF ADJUSTMENTS OF CONVERSION PRICE....................80
SECTION 13.06.   NOTICE OF CERTAIN CORPORATE ACTION...........................80
SECTION 13.07.   COMPANY TO RESERVE COMMON STOCK..............................81
SECTION 13.08.   TAXES ON CONVERSIONS.........................................81
SECTION 13.09.   COVENANT AS TO COMMON STOCK..................................81
SECTION 13.10.   CANCELLATION OF CONVERTED SECURITIES.........................81
SECTION 13.11.   PROVISIONS IN CASE OF RECLASSIFICATION, CONSOLIDATION, 
                  MERGER OR SALE OF ASSETS ...................................81

                                   ARTICLE XIV

                           RIGHT TO REQUIRE REPURCHASE

SECTION 14.01.   RIGHT TO REQUIRE REPURCHASE..................................82
SECTION 14.02.   NOTICE, METHOD OF EXERCISING REPURCHASE RIGHT................82
SECTION 14.03.   DEPOSIT OF REPURCHASE PRICE..................................83
SECTION 14.04.   SECURITIES NOT REPURCHASED ON REPURCHASE DATE................83
SECTION 14.05.   SECURITIES REPURCHASED IN PART...............................83
SECTION 14.06.   CERTAIN DEFINITIONS..........................................84

                                   ARTICLE XV

                       DEFEASANCE AND COVENANT DEFEASANCE

SECTION 15.01.   COMPANY'S OPTION TO EFFECT DEFEASANCE OR COVENANT DEFEASANCE.85
SECTION 15.02.   DEFEASANCE AND DISCHARGE.....................................85
SECTION 15.03.   COVENANT DEFEASANCE..........................................85
SECTION 15.04.   CONDITIONS TO DEFEASANCE OR COVENANT DEFEASANCE..............86
SECTION 15.05.   DEPOSITED MONEY AND U.S. GOVERNMENT OBLIGATIONS TO BE 
                  HELD IN TRUST; OTHER MISCELLANEOUS PROVISIONS...............88
SECTION 15.06.   REINSTATEMENT................................................88


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                                   ARTICLE XVI

                                    IMMUNITY

SECTION 16.01.   PERSONAL IMMUNITY OF INCORPORATORS, SHAREHOLDERS, 
                  DIRECTORS AND OFFICERS .....................................89


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            INDENTURE, dated as of October 15, 1997, between SPACEHAB,
INCORPORATED, a corporation duly organized and existing under the laws of the
State of Washington (herein called the "Company"), having its principal office
at 1595 Spring Hill Road, Suite 360, Vienna, Virginia 22182, and First Union
National Bank, as Trustee (herein called the "Trustee").

                             RECITALS OF THE COMPANY

            The Company has duly authorized the execution and delivery of this
Indenture to provide for the issuance of its 8% Convertible Subordinated Notes
due 2007 (herein called the "Securities"), to be issued as in this Indenture
provided.

            All things necessary to make the Securities, 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 Indenture a
valid agreement of the Company, in accordance with their and its terms, have
been done.

                   NOW, THEREFORE, THIS INDENTURE WITNESSETH:

            For and in consideration of the premises and the purchase of the
Securities by the Holders thereof, it is mutually agreed, for the equal and
proportionate benefit of all Holders of the Securities or of any series thereof,
as follows:

                                    ARTICLE I

             Definitions and Other Provisions of General Application

            SECTION 1.01 Definitions. For all purposes of this Indenture, except
as otherwise expressly provided or unless the context otherwise requires:

            1. the terms defined in this Article have the meanings assigned to
them in this Article and include the plural as well as the singular;

            2. all other terms used herein which are defined in the Trust
Indenture Act, either directly or by reference therein, have the meanings
assigned to them therein; 

            3. all accounting terms not otherwise defined herein have the
meanings assigned to them in accordance with generally accepted accounting
principles, and, except as otherwise herein expressly provided, the term
"generally accepted accounting principles" with respect to any computation
required or permitted hereunder shall mean such accounting principles as are
generally accepted at the date of such computation;

            4. unless the context otherwise requires, any reference to an
"Article" or a "Section" refers to an Article or Section, as the case may be, of
this Indenture; and 

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            5. the words "herein", "hereof" and "hereunder" and other words of
similar import refer to this Indenture as a whole and not to any particular
Article, Section or other subdivision. 

            Certain terms used in Article XIV have the meanings specified
therein.

            "Act", when used with respect to any Holder, has the meaning
specified in Section 1.04.

            "Additional Interest" has the meaning specified in Section 10.11.

            "Affiliate" of any specified Person means any other Person who
directly, or indirectly through one or more intermediaries, controls, is
controlled by, or is under common control with, such specified Person. For the
purposes of this definition, "control" when used with respect to any specified
Person means the power to direct the management and policies of such Person,
directly or indirectly, whether through the ownership of voting securities, by
contract or otherwise; and the terms "controlling" and "controlled" have
meanings correlative to the foregoing.

            "Agent Member" means any member of, or participant in, the
Depositary.

            "Applicable Procedures" means, with respect to any transfer or
transaction involving a Global Security or beneficial interest therein, the
rules and procedures of the Depositary for such Security, in each case to the
extent applicable to such transaction and as in effect from time to time.

            "Authenticating Agent" means any Person authorized by the Trustee
pursuant to Section 6.14 to act on behalf of the Trustee to authenticate
Securities.

            "Board of Directors" means either the board of directors of the
Company or any duly authorized committee of that board.

            "Board Resolution" means a copy of a resolution certified by the
Secretary or an Assistant Secretary of the Company to have been duly adopted by
the Board of Directors and to be in full force and effect on the date of such
certification, and delivered to the Trustee.

            "Business Day" means a day on which banking institutions are open
for business and carrying out transactions in Dollars at the relevant place of
payment.

            "Change in Control" has the meaning specified in Section 14.06.

            "Closing Price" on any Trading Day with respect to the per share
price of Common Stock means the last reported sales price regular way or, in
case no such reported sale takes place on such Trading Day, the average of the
reported closing bid and asked prices regular way, in either case on the New
York Stock Exchange or, if the Common Stock is not listed or admitted to trading
on the New York Stock Exchange, on the principal national securities exchange on
which the Common Stock is listed or 


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admitted to trading, or, if not listed or admitted to trading on any national
securities exchange, on The Nasdaq Stock Market, Inc. ("Nasdaq") or, if the
Common Stock is not listed or admitted to trading on any national securities
exchange or Nasdaq, the average of the closing bid and asked prices in the
over-the-counter market as furnished by any New York Stock Exchange member firm
that is selected from time to time by the Company for that purpose and is
reasonably acceptable to the Trustee.

            "Commencement Date" has the meaning specified in Section 13.04.

            "Commission" means the Securities and Exchange Commission, as from
time to time constituted, created under the Exchange Act, or, if at any time
after the execution of this instrument such Commission is not existing and
performing the duties now assigned to it under the Trust Indenture Act, then the
body performing such duties at such time.

            "Common Stock" includes any stock of any class of the Company which
has no preference in respect of dividends or of amounts payable in the event of
any voluntary or involuntary liquidation, dissolution or winding-up of the
Company and which is not subject to redemption by the Company. However, subject
to the provisions of Section 13.11, shares issuable on conversion of Securities
shall include only shares of the class designated as Common Stock of the Company
at the date of this instrument or shares of any class or classes resulting from
any reclassification or reclassifications thereof and which have no preference
in respect of dividends or of amounts payable in the event of any voluntary or
involuntary liquidation, dissolution or winding-up of the Company and which are
not subject to redemption by the Company; provided that if at any time there
shall be more than one such resulting class, the shares of each such class then
so issuable shall be substantially in the proportion which the total number of
shares of such class resulting from all such reclassifications bears to the
total number of shares of all such classes resulting from all such
reclassifications.

            "Company" means the Person named as the "Company" in the first
paragraph of this instrument until a successor Person shall have become such
pursuant to the applicable provisions of this Indenture, and thereafter
"Company" shall mean such successor Person.

            "Company Request" or "Company Order" means a written request or
order signed in the name of the Company by its Chairman of the Board, its Vice
Chairman of the Board, its President or a Vice President, and by its Treasurer,
an Assistant Treasurer, its Secretary or an Assistant Secretary, and delivered
to the Trustee.

            "Corporate Trust Office" means the principal office of the Trustee
in the city at which at any particular time its corporate trust business shall
be administered. As of the date hereof, the Corporate Trust Office of the
Trustee is located at 901 East Cary Street, Second Floor, Richmond, Virginia
23219.

            "Corporation" means a corporation, association, company, joint-stock
company or business trust.


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            "Defaulted Interest" has the meaning specified in Section 3.07.

            "Definitive Security" means a certificated Security in the form set
forth in Sections 2.02 and 2.03, bearing the restricted securities legend set
forth in Section 2.02, and held by an Institutional Accredited Investor in
accordance with Section 2.01.

            "Depositary" means, with respect to the Securities issued in whole
or in part in the form of one or more Global Securities, a clearing agency
registered under the Exchange Act that is designated to act as Depositary for
such Securities as contemplated by Section 2.01 (or any successor securities
clearing agency so registered) .

            "Distribution Date" has the meaning specified in Section 13.04.

            "Dollar" or "U.S.$" means a Dollar or other equivalent unit in such
coin or currency of the United States as at the time shall be legal tender for
the payment of public and private debts.

            "DTC" means The Depository Trust Company, a New York corporation.

            "Event of Default" has the meaning specified in Section 5.01.

            "Excess Shares" has the meaning specified in Section 2.03.

            "Exchange Act" means the Securities Exchange Act of 1934 as it may
be amended from time to time, and any successor act thereto, and the rules and
regulations of the Commission promulgated thereunder.

            "Expiration Date" has the meaning specified in Section 1.04.

            "Expiration Time" has the meaning specified in Section 13.04.

            "Global Security" means a Security that is registered in the
Security Register in the name of a Depositary or a nominee thereof.

            "Holder" means a Person in whose name a Security is registered in
the Security Register.

            "Indenture" means this instrument as originally executed or as it
may from time to time be supplemented or amended by one or more indentures
supplemental hereto entered into pursuant to the applicable provisions hereof,
including, for all purposes of this instrument and any such supplemental
indenture, the provisions of the Trust Indenture Act that are deemed to be a
part of and govern this instrument and any such supplemental indenture,
respectively.

            "Initial Purchasers" means Credit Suisse First Boston Corporation,
CIBC Wood Gundy Securities Corp. and Oppenheimer & Co., Inc.


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            "Institutional Accredited Investor" means an institutional
"accredited investor" as described in Rule 501(a)(1), (2), (3) or (7) under the
Securities Act.

            "Interest Payment Date" means the Stated Maturity of an installment
of interest on the Securities.

            "Issue Date" means the date of first issuance of the Securities
under this Indenture.

            "Maturity", when used with respect to any Security, means the date
on which the principal of such Security or an installment of principal becomes
due and payable as therein or herein provided, whether at the Stated Maturity or
by declaration of acceleration, call for redemption, exercise of the repurchase
right or otherwise.

            "Non-Recourse Obligation" means indebtedness or other obligation or
that portion of indebtedness or other obligation incurred by a Subsidiary (the
"Non-Recourse Subsidiary") with respect to the acquisition of assets not
previously owned by the Company or any Subsidiary or the financing of a project
involving the development or expansion of properties of the Company or any
Subsidiary (i) as to which neither the Company nor any of its Subsidiaries
(other than the Non-Recourse Subsidiary) (a) provides credit support (including
any undertaking, agreement or instrument that would constitute indebtedness),
(b) is directly or indirectly liable (as a guarantor or otherwise), or (c)
constitutes the lender; and (ii) no default with respect to which would permit
(upon notice, lapse of time or both) any holder of any other indebtedness of the
Company or any of its Subsidiaries to declare a default under such other
indebtedness or cause the payment thereof to be accelerated or payable prior to
its stated maturity; and (iii) as to which the lenders have been notified in
writing that they will not have any recourse to the stock or assets of the
Company or any Subsidiary other than the assets that were acquired with the
proceeds of such transaction or the project financed with the proceeds of such
transaction (and the proceeds thereof).

            "Notice of Default" means a written notice of the kind specified in
Section 5.01(3) or 5.01(4).

            "Officers' Certificate" means a certificate signed by any of the
Chairman of the Board, a Vice Chairman of the Board, the President or a Vice
President, and by any of the Treasurer, an Assistant Treasurer, the Secretary or
an Assistant Secretary, of the Company, and delivered to the Trustee. One of the
officers signing an Officers' Certificate given pursuant to Section 10.04 shall
be the principal executive, financial or accounting officer of the Company.

            "Opinion of Counsel" means a written opinion of counsel, who may be
counsel for the Company.

            "Outstanding", when used with respect to Securities, means, as of
the date of determination, all Securities theretofore authenticated and
delivered under this Indenture, except:


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            (i) Securities theretofore cancelled by the Trustee or delivered to
the Trustee for cancellation;

            (ii) Securities for whose payment or redemption money in the
necessary amount has been theretofore deposited with the Trustee or any Paying
Agent (other than the Company) in trust or set aside and segregated in trust by
the Company (if the Company shall act as its own Paying Agent) for the Holders
of such Securities; provided that, if such Securities are to be redeemed, notice
of such redemption shall have been duly given pursuant to this Indenture or
provision therefor satisfactory to the Trustee shall have been made; 

            (iii) Securities which have been paid pursuant to Section 3.06 or in
exchange for or in lieu of which other Securities have been authenticated and
delivered pursuant to this Indenture, other than any such Securities in respect
of which there shall have been presented to the Trustee proof satisfactory to it
that such Securities are held by a bona fide purchaser in whose hands such
Securities are valid obligations of the Company; and

            (iv) Securities which have been defeased pursuant to Section 15.02;

provided, however, that in determining whether the Holders of the requisite
principal amount of the Outstanding Securities have given, made or taken any
request, demand, authorization, direction, notice, consent, waiver or other
action hereunder as of any date, Securities owned by the Company or any other
obligor upon the Securities or any Affiliate of the Company or of such other
obligor shall be disregarded and deemed not to be Outstanding, except that, in
determining whether the Trustee shall be protected in relying upon any such
request, demand, authorization, direction, notice, consent, waiver or other
action, only Securities which the Trustee knows to be so owned shall be so
disregarded. Securities so owned which have been pledged in good faith may be
regarded as Outstanding if the pledgee establishes to the satisfaction of the
Trustee the pledgee's right so to act with respect to such Securities and that
the pledgee is not the Company or any other obligor upon the Securities or any
Affiliate of the Company or of such other obligor.

            "Paying Agent" means any Person authorized by the Company to pay the
principal of (and premium, if any) or interest on any Securities on behalf of
the Company.

            "Person" means any individual, corporation, partnership, joint
venture, trust, unincorporated organization or government or any agency or
political subdivision thereof.

            "Predecessor Security" of any particular Security means every
previous Security evidencing all or a portion of the same debt as that evidenced
by such particular Security; and, for the purposes of this definition, any
Security authenticated and delivered under Section 3.06 in exchange for or in
lieu of a mutilated, destroyed, lost or stolen 


                                       6
   14

Security shall be deemed to evidence the same debt as the mutilated, destroyed,
lost or stolen Security.

            "Purchased Shares" has the meaning specified in Section 13.04.

            "Qualified Institutional Buyer" means a "qualified institutional
buyer" as defined in Rule 144A.

            "Redemption Date", when used with respect to any Security to be
redeemed, means the date fixed for such redemption by or pursuant to this
Indenture.

            "Redemption Price", when used with respect to any Security to be
redeemed, means the price at which it is to be redeemed as set forth in the
Securities.

            "Reference Date" has the meaning specified in Section 13.04.

            "Registration Default" has the meaning specified in Section 10. 11.

            "Registration Rights Agreement" has the meaning specified in Section
10.11.

            "Regular Record Date" for the interest payable on any Interest
Payment Date means the April 1 or October 1 (whether or not a Business Day), as
the case may be, next preceding such Interest Payment Date.

            "Regulation S" means Regulation S under the Securities Act (or any
successor provision), as it may be amended from time to time.

            "Repurchase Date" has the meaning specified in Section 14.01.

            "Repurchase Price" has the meaning specified in Section 14.01.

            "Responsible Officer", when used with respect to the Trustee, means
the President or any Vice President, Assistant Vice President or Trust Officer
of the Trustee to whom any matter has been referred because of such officer's
knowledge and familiarity with the particular subject.

            "Restricted Global Security" has the meaning specified in Section
2.01.

            "Restricted Security" means a Security required to bear the
restricted securities legend set forth in Section 2.02.

            "Rule 144A" means Rule 144A under the Securities Act (or any
successor provision), as it may be amended from time to time.

            "Rule 144A Information" has the meaning specified in Section 10.09.


                                       7
   15

            "Securities" has the meaning stated in the first recital of this
Indenture and more particularly means any Securities authenticated and delivered
under this Indenture and "Security" means one of such Securities.

            "Securities Act" means the Securities Act of 1933 as it may be
amended from time to time, and any successor act thereto, and the rules and
regulations of the Commission promulgated thereunder.

            "Security Register" and "Security Registrar" have the respective
meanings specified in Section 3.05.

            "Senior Indebtedness" means the principal of and premium, if any,
and interest on all indebtedness of the Company for money borrowed, other than
the Securities, whether outstanding on the date of execution of the Indenture or
thereafter created, incurred, guaranteed or assumed, except such indebtedness
that by the terms of the instrument or instruments by which such indebtedness
was created or incurred expressly provides that it (i) is junior in right of
payment to the Securities or any other indebtedness of the Company for borrowed
money or (ii) ranks pari passu in right of payment to the Securities. The term
"indebtedness for money borrowed" when used with respect to the Company is
defined to mean (i) any obligation of, or any obligation guaranteed by, the
Company for the repayment of borrowed money, whether or not evidenced by bonds,
debentures, notes or other written instruments, (ii) all obligations of the
Company with respect to interest rate hedging agreements to hedge interest rates
relating to Senior Indebtedness of the Company, (iii) any deferred payment
obligation of, or any such obligation guaranteed by, the Company for the payment
of the purchase price of property or assets evidenced by a note or similar
instrument, and (iv) any obligation of, or any such obligation guaranteed by,
the Company for the payment of rent or other amounts under a lease of property
or assets which obligation is required to be classified and accounted for as a
capitalized lease on the balance sheet of the Company under generally accepted
accounting principles.

            "Shelf Registration Statement" has the meaning specified in Section
10.11.

            "Special Record Date" for the payment of any Defaulted Interest
means a date fixed by the Trustee pursuant to Section 3.07.

            "Stated Maturity", when used with respect to any Security or any
installment of principal thereof or interest thereon, means the date specified
in such Security as the fixed date on which the principal of such Security or
such installment of principal or interest is due and payable.

            "Subsidiary" means a corporation more than 50% of the outstanding
voting stock of which is owned, directly or indirectly, by the Company or by one
or more other Subsidiaries, or by the Company and one or more other
Subsidiaries. For the purposes of this definition, "voting stock" means stock
which ordinarily has voting power for the election of directors, whether at all
times or only so long as no senior class of stock has such voting power by
reason of any contingency.


                                       8
   16

            "Surrendered Securities" has the meaning specified in Section 2.06.

            "Trading Day" means each Monday, Tuesday, Wednesday, Thursday and
Friday, other than any day on which securities are not traded on the applicable
securities exchange or in the applicable securities market.

            "Transfer Restricted Securities" has the meaning specified in the
Registration Rights Agreement.

            "Trust Indenture Act" means the Trust Indenture Act of 1939 as in
force at the date as of which this instrument was executed and the rules and
regulations thereunder; provided, however, that in the event the Trust Indenture
Act of 1939 or such rules and regulations are amended after such date, "Trust
Indenture Act" means, to the extent required by any such amendment, the Trust
Indenture Act of 1939 and such rules and regulations as so amended.

            "Trustee" means the Person named as the "Trustee" in the first
paragraph of this instrument until a successor Trustee shall have become such
pursuant to the applicable provisions of this Indenture, and thereafter
"Trustee" shall mean such successor Trustee.

            "United States" means the United States of America (including the
States thereof and the District of Columbia), its territories, its possessions
and other areas subject to its jurisdiction.

            "U.S. Government Obligation" has the meaning specified in Section
15.04.

            "Vice President", when used with respect to the Company or the
Trustee, means any vice president, whether or not designated by a number or a
word or words added before or after the title "vice president".

            SECTION 1.02. Compliance Certificates and Opinions. Upon any
application or request by the Company to the Trustee to take any action under
any provision of this Indenture, the Company shall furnish to the Trustee an
Officers' Certificate, if to be given by an officer of the Company, or an
Opinion of Counsel, if to be given by counsel, stating that all conditions
precedent, if any, provided for in this Indenture relating to the proposed
action have been complied with.

            Every certificate or opinion with respect to compliance with a
condition or covenant provided for in this Indenture shall include:

            (1) a statement that each individual signing such certificate or
      opinion has read such covenant or condition and the definitions herein
      relating thereto;

            (2) a brief statement as to the nature and scope of the examination
      or investigation upon which the statements or opinions contained in such
      certificate or opinion are based; 


                                       9
   17

            (3) a statement that, in the opinion of each such individual, he has
      made such examination or investigation as is necessary to enable him to
      express an informed opinion as to whether or not such covenant or
      condition has been complied with; and

            (4) a statement as to whether, in the opinion of each such
      individual, such condition or covenant has been complied with.

            SECTION 1.03. Form of Documents Delivered to Trustee. In any case
where several matters are required to be certified by, or covered by an opinion
of, any specified Person, it is not necessary that all such matters be certified
by, or covered by the opinion of, only one such Person, or that they be so
certified or covered by only one document, but one such Person may certify or
give an opinion with respect to some matters and one or more other such Persons
as to other matters, and any such Person may certify or give an opinion as to
such matters in one or several documents.

            Any certificate or opinion of an officer of the Company may be
based, insofar as it relates to legal matters, upon a certificate or opinion of,
or representations by, counsel, unless such officer knows, or in the exercise of
reasonable care should know, that the certificate or opinion or representations
with respect to the matters upon which his certificate or opinion is based are
erroneous. Any such certificate or Opinion of Counsel may be based, insofar as
it relates to factual matters, upon a certificate or opinion of, or
representations by, an officer or officers of the Company stating that the
information with respect to such factual matters is in the possession of the
Company, unless such counsel knows, or in the exercise of reasonable care should
know, that the certificate or opinion or representations with respect to such
matters are erroneous.

            Where any Person is required to make, give or execute two or more
applications, requests, consents, certificates, statements, opinions or other
instruments under this Indenture, they may, but need not, be consolidated and
form one instrument.

            SECTION 1.04. Acts of Holders; Record Dates. Any request, demand,
authorization, direction, notice, consent, waiver or other action provided or
permitted by this Indenture to be given or taken by Holders may be embodied in
and evidenced by one or more instruments of substantially similar tenor signed
by such Holders in person or by an agent duly appointed in writing; and, except
as herein otherwise expressly provided, such action shall become effective when
such instrument or instruments are delivered to the Trustee and, where it is
hereby expressly required, to the Company. Such instrument or instruments (and
the action embodied therein and evidenced thereby) are herein sometimes referred
to as the "Act" of the Holders signing such instrument or instruments. Proof of
execution of any such instrument or of a writing appointing any such agent shall
be sufficient for any purpose of this Indenture and (subject to Section 6.01)
conclusive in favor of the Trustee and the Company, if made in the manner
provided in this Section.

            The fact and date of the execution by any Person of any such
instrument or writing may be proved by the affidavit of a witness of such
execution or by a certificate 


                                       10
   18

of a notary public or other officer authorized by law to take acknowledgments of
deeds, certifying that the individual signing such instrument or writing
acknowledged to him the execution thereof. Where such execution is by a signer
acting in a capacity other than his individual capacity, such certificate or
affidavit shall also constitute sufficient proof of his authority. The fact and
date of the execution of any such instrument or writing, or the authority of the
Person executing the same, may also be proved in any other manner which the
Trustee deems sufficient.

            The ownership of Securities shall be proved by the Security
Register.

            Any request, demand, authorization, direction, notice, consent,
waiver or other Act of the Holder of any Security shall bind every future Holder
of the same Security and the Holder of every Security issued upon the
registration of transfer thereof or in exchange therefor or in lieu thereof in
respect of anything done, omitted or suffered to be done by the Trustee or the
Company in reliance thereon, whether or not notation of such action is made upon
such Security.

            The Company may set any day as a record date for the purpose of
determining the Holders of Outstanding Securities entitled to give or take any
request, demand, authorization, direction, notice, consent, waiver or other
action provided or permitted by this Indenture to be given or taken by Holders
of Securities; provided that the Company may not set a record date for, and the
provisions of this paragraph shall not apply with respect to, the giving or
making of any notice, declaration, request or direction referred to in the next
paragraph. If any record date is set pursuant to this paragraph, the Holders of
Outstanding Securities on such record date, and no other Holders, shall be
entitled to take the relevant action, whether or not such Holders remain Holders
after such record date; provided that no such action shall be effective
hereunder unless taken on or prior to the applicable Expiration Date by Holders
of the requisite principal amount of Outstanding Securities on such record date;
and provided, further, that for the purpose of determining whether Holders of
the requisite principal amount of such Securities have taken such action, no
Security shall be deemed to have been Outstanding on such record date unless it
is also Outstanding on the date such action is to become effective. Nothing in
this paragraph shall prevent the Company from setting a new record date for any
action for which a record date has previously been set pursuant to this
paragraph (whereupon the record date previously set shall automatically and with
no action by any Person be cancelled and of no effect), nor shall anything in
this paragraph be construed to render ineffective any action taken by Holders of
the requisite principal amount of Outstanding Securities on the date such action
is taken. Promptly after any record date is set pursuant to this paragraph, the
Company, at its own expense, shall cause notice of such record date, the
proposed action by Holders and the applicable Expiration Date to be given to the
Trustee in writing and to each Holder of Securities in the manner set forth in
Section 1.06.

            The Trustee may set any day as a record date for the purpose of
determining the Holders of Outstanding Securities entitled to join in the giving
or making of (i) any Notice of Default, (ii) any declaration of acceleration
referred to in Section 5.02, (iii) any request to institute proceedings referred
to in Section 5.07(2) or (iv) any 


                                       11
   19

direction referred to in Section 5.12. If any record date is set pursuant to
this paragraph, the Holders of Outstanding Securities on such record date, and
no other Holders, shall be entitled to join in such notice, declaration, request
or direction, whether or not such Holders remain Holders after such record date;
provided that no such action shall be effective hereunder unless taken on or
prior to the applicable Expiration Date by Holders of the requisite principal
amount of Outstanding Securities on such record date; and provided, further,
that for the purpose of determining whether Holders of the requisite principal
amount of such Securities have taken such action, no Security shall be deemed to
have been Outstanding on such record date unless it is also Outstanding on the
date such action is to become effective. Nothing in this paragraph shall be
construed to prevent the Trustee from setting a new record date for any action
(whereupon the record date previously set shall automatically and without any
action by any Person be cancelled and of no effect), nor shall anything in this
paragraph be construed to render ineffective any action taken by Holders of the
requisite principal amount of Outstanding Securities on the date such action is
taken. Promptly after any record date is set pursuant to this paragraph, the
Trustee, at the Company's expense, shall cause notice of such record date, the
proposed action by Holders and the applicable Expiration Date to be given to the
Company in writing and to each Holder of Securities in the manner set forth in
Section 1.06.

            With respect to any record date set pursuant to this Section, the
party hereto that sets such record date may designate any day as the "Expiration
Date" and from time to time may change the Expiration Date to any earlier or
later day, provided that no such change shall be effective unless notice of the
proposed new Expiration Date is given to the other party hereto in writing, and
to each Holder of Securities in the manner set forth in Section 1.06, on or
before the existing Expiration Date. Notwithstanding the foregoing, no
Expiration Date shall be later than the 180th day after the applicable record
date and, if an Expiration Date is not designated with respect to any record
date set pursuant to this Section, the party hereto that set such record date
shall be deemed to have designated the 180th day after such record date as the
Expiration Date with respect thereto.

            Without limiting the foregoing, a Holder entitled hereunder to take
any action hereunder with regard to any particular Security may do so with
regard to all or any part of the principal amount of such Security or by one or
more duly appointed agents, each of which may do so pursuant to such appointment
with regard to all or any part of such principal amount.

            SECTION 1.05. Notices, Etc., to Trustee and Company. Any request,
demand, authorization, direction, notice, consent, waiver or Act of Holders or
other document provided or permitted by this Indenture to be made upon, given or
furnished to, or filed with,

            (1) the Trustee by any Holder or by the Company shall be
      sufficiently given if made, given, furnished or filed in writing to or
      with the Trustee at its Corporate Trust Office, Attention: Corporate Trust
      Department, or at any other address previously furnished in writing to the
      Company by the Trustee, or


                                       12
   20

            (2) the Company by the Trustee or by any Holder shall be
      sufficiently given (unless otherwise herein expressly provided) if in
      writing and mailed, first-class postage prepaid, to the Company, addressed
      to it at the address of its principal office specified in the first
      paragraph of this instrument or at any other address previously furnished
      in writing to the Trustee by the Company. 

            SECTION 1.06. Notice to Holders; Waiver. Where this Indenture
provides for notice to Holders of any event, such notice shall be sufficiently
given (unless otherwise herein expressly provided) if in writing and mailed,
first-class postage prepaid, to each Holder affected by such event, at his
address as it appears in the Security Register, not later than the latest date
(if any), and not earlier than the earliest date (if any), prescribed for the
giving of such notice. In any case where notice to Holders is given by mail,
neither the failure to mail such notice, nor any defect in any notice so mailed,
to any particular Holder shall affect the sufficiency of such notice with
respect to other Holders. Where this Indenture provides for notice in any
manner, such notice may be waived in writing by the Person entitled to receive
such notice, either before or after the event, and such waiver shall be the
equivalent of such notice. Waivers of notice by Holders shall be filed with the
Trustee, but such filing shall not be a condition precedent to the validity of
any action taken in reliance upon such waiver.

            In case by reason of the suspension of regular mail service or by
reason of any other cause it shall be impracticable to give such notice by mail,
then such notification as shall be made with the approval of the Trustee shall
constitute a sufficient notification for every purpose hereunder.

            SECTION 1.07. Conflict with Trust Indenture Act. If any provision
hereof limits, qualifies or conflicts with a provision of the Trust Indenture
Act which is required under such Act to be a part of and govern this Indenture,
the latter provision shall control. If any provision of this Indenture modifies
or excludes any provision of the Trust Indenture Act which may be so modified or
excluded, the latter provision shall be deemed to apply to this Indenture so
modified or to be excluded, as the ease may be. To the extent a Security
conflicts with a provision in the Indenture, the Indenture governs.

            SECTION 1.08. Effect of Headings and Table of Contents. The Article
and Section headings herein and the Table of Contents are for convenience only
and shall not affect the construction hereof.

            SECTION 1.09. Successors and Assigns. All covenants and agreements
in this Indenture by the Company shall bind its successors and assigns, whether
so expressed or not.

            SECTION 1.10. Severability Clause. In case any provision in this
Indenture or in the Securities shall be invalid, illegal or unenforceable, the
validity, legality and enforceability of the remaining provisions shall not in
any way be affected or impaired thereby.


                                       13
   21

            SECTION 1.11. Benefits of Indenture. Nothing in this Indenture or in
the Securities, express or implied, shall give to any Person, other than the
parties hereto and their successors hereunder, the holders of Senior
Indebtedness and the Holders of Securities, any benefit or any legal or
equitable right, remedy or claim under this Indenture.

            SECTION 1.12. Governing Law. THIS INDENTURE AND THE SECURITIES SHALL
BE GOVERNED BY AND CONSTRUED IN ACCORDANCE WITH THE LAW OF THE STATE OF NEW
YORK.

            SECTION 1.13. Legal Holidays. In any case where any Interest Payment
Date, Redemption Date, Repurchase Date or Stated Maturity of any Security or the
last date on which a Holder has the right to convert his Securities shall not be
a Business Day then (notwithstanding any other provision of this Indenture or of
the Securities) payment of interest or principal (and premium, if any) or
conversion of the Securities need not be made on such date, but may be made on
the next succeeding Business Day with the same force and effect as if made on
the Interest Payment Date, Redemption Date, Repurchase Date or at the Stated
Maturity, or on such last day for conversion, provided that no interest shall
accrue for the period from and after such Interest Payment Date, Redemption
Date, Repurchase Date or Stated Maturity, as the case may be.

                                   ARTICLE II

                                 Security Forms

            SECTION 2.01. Forms Generally. The Securities, the conversion notice
and the Trustee's certificates of authentication shall be in substantially the
forms set forth in this Article, with such appropriate insertions, omissions,
substitutions and other variations as are required or permitted by this
Indenture, and may have such letters, numbers or other marks of indemnification
and such legends or endorsements placed thereon as may be required to comply
with the rules of any securities exchange or Depositary therefor or as may,
consistently herewith, be determined by the officers executing such Securities,
as evidenced by their execution of the Securities.

            The definitive Securities shall be printed, lithographed or engraved
on steel engraved borders or may be produced in any other manner, all as
determined by the officers executing such Securities, as evidenced by their
execution of such Securities.

            In certain cases described elsewhere herein, the legends set forth
in the first four paragraphs of Section 2.02 may be omitted from Securities
issued hereunder.

            Upon their original issuance, Securities offered and sold in
reliance on Rule 144A or in reliance on Regulation S, in each case as provided
in the Purchase Agreement, shall be issued in the form of a single Global
Security in definitive, fully registered form without interest coupons,
substantially in the form of Security set forth in Sections 2.02 and 2.03, with
such applicable legends as are provided for in Section 2.02, 


                                       14
   22

except as otherwise permitted herein. Such Global Security shall be registered
in the name of DTC, as Depositary, or its nominee, duly executed by the Company
and authenticated by the Trustee as hereinafter provided, and deposited with the
Trustee, as custodian for DTC, for credit by DTC to the respective accounts of
beneficial owners of the Securities represented thereby (or such other accounts
as they may direct). Such Global Security, together with its Successor
Securities which are Global Securities, are collectively herein called the
"Restricted Global Security".

            Except as provided in this Section 2.01 or Section 3.05, owners of
beneficial interests in Global Securities will not be entitled to receive
physical delivery of certificated Securities. Purchasers of Securities who are
Institutional Accredited Investors and are not Qualified Institutional Buyers
and did not purchase Securities sold in reliance on Regulation S will receive
Definitive Securities. Upon transfer of such Definitive Securities to a
Qualified Institutional Buyer or in reliance on Regulation S, such Definitive
Securities will, unless the Restricted Global Security has previously been
exchanged, be exchanged for an interest in the Restricted Global Security
pursuant to the provisions of Section 3.05.

            Neither the Company nor the Trustee shall have any responsibility
for any defect in the CUSIP or ISIN number that appears on any Security, check,
advice of payment or redemption or repurchase notice, and any such document may
contain a statement to the effect that CUSIP or ISIN numbers have been assigned
by an independent service for convenience of reference and that neither the
Company nor the Trustee shall be liable for any inaccuracy in such numbers.

            SECTION 2.02. Form of Face of Security.

            [INCLUDE IF SECURITY IS A RESTRICTED SECURITY OR A DEFINITIVE
SECURITY OTHER THAN A RESTRICTED GLOBAL SECURITY:

            THIS SECURITY (OR ITS PREDECESSOR) WAS ORIGINALLY ISSUED IN A
TRANSACTION EXEMPT FROM REGISTRATION UNDER THE UNITED STATES SECURITIES ACT OF
1933, AS AMENDED (THE "SECURITIES ACT"), AND THIS SECURITY AND THE COMMON STOCK
ISSUABLE UPON THE CONVERSION THEREOF MAY NOT BE OFFERED, SOLD OR OTHERWISE
TRANSFERRED IN THE ABSENCE OF SUCH REGISTRATION OR IN A TRANSACTION EXEMPT FROM,
OR NOT SUBJECT TO, THE SECURITIES ACT. EACH PURCHASER OF THIS SECURITY IS HEREBY
NOTIFIED THAT THE SELLER OF THIS SECURITY, AND THE COMMON STOCK ISSUABLE UPON
THE CONVERSION THEREOF, MAY BE RELYING ON THE EXEMPTION FROM THE PROVISIONS OF
SECTION 5 OF THE SECURITIES ACT PROVIDED BY RULE 144A THEREUNDER.

            THE HOLDER OF THIS SECURITY AGREES FOR THE BENEFIT OF THE COMPANY
THAT (A) THIS SECURITY AND THE COMMON STOCK ISSUABLE UPON THE CONVERSION THEREOF
MAY BE OFFERED, RESOLD, PLEDGED OR OTHERWISE TRANSFERRED, ONLY (I) INSIDE THE
UNITED 


                                       15
   23

STATES TO A PERSON WHOM THE SELLER REASONABLY BELIEVES IS A QUALIFIED
INSTITUTIONAL BUYER (AS DEFINED IN RULE 144A UNDER THE SECURITIES ACT) IN A
TRANSACTION MEETING THE REQUIREMENTS OF RULE 144A, (II) OUTSIDE THE UNITED
STATES IN AN OFFSHORE TRANSACTION IN ACCORDANCE WITH RULE 904 UNDER THE
SECURITIES ACT, (III) PURSUANT TO AN EXEMPTION FROM REGISTRATION UNDER THE
SECURITIES ACT PROVIDED BY RULE 144 THEREUNDER (IF AVAILABLE) OR (IV) PURSUANT
TO AN EFFECTIVE REGISTRATION STATEMENT UNDER THE SECURITIES ACT, IN EACH OF
CASES (I) THROUGH (IV) IN ACCORDANCE WITH ANY APPLICABLE SECURITIES LAWS OF ANY
STATE OF THE UNITED STATES, AND (B) THE HOLDER WILL, AND EACH SUBSEQUENT HOLDER
IS REQUIRED TO, NOTIFY ANY PURCHASER OF THIS SECURITY AND ANY SHARES OF COMMON
STOCK ISSUABLE UPON THE CONVERSION THEREOF OF THE RESALE RESTRICTIONS REFERRED
TO IN (A) ABOVE.]

            [INCLUDE IF SECURITY IS A RESTRICTED GLOBAL SECURITY:

            THE SECURITIES EVIDENCED BY THIS GLOBAL SECURITY (OR ITS
PREDECESSOR) WERE ORIGINALLY ISSUED IN A TRANSACTION EXEMPT FROM REGISTRATION
UNDER THE UNITED STATES SECURITIES ACT OF 1933, AS AMENDED (THE "SECURITIES
ACT"), AND SUCH SECURITIES AND THE COMMON STOCK ISSUABLE UPON THE CONVERSION
THEREOF MAY NOT BE OFFERED, SOLD OR OTHERWISE TRANSFERRED IN THE ABSENCE OF SUCH
REGISTRATION OR IN A TRANSACTION EXEMPT FROM, OR NOT SUBJECT TO, THE SECURITIES
ACT. EACH PURCHASER OF ANY BENEFICIAL INTEREST IN THE SECURITIES IS HEREBY
NOTIFIED THAT THE SELLER OF SUCH BENEFICIAL INTEREST MAY BE RELYING ON THE
EXEMPTION FROM THE PROVISIONS OF SECTION 5 OF THE SECURITIES ACT PROVIDED BY
RULE 144A THEREUNDER.

            EACH BENEFICIAL OWNER OF AN INTEREST IN ANY OF THE SECURITIES
EVIDENCED BY THIS GLOBAL SECURITY INCLUDING ANY PARTICIPANT IN THE DEPOSITARY
HOLDING THE GLOBAL SECURITY THAT IS SHOWN AS HOLDING SUCH AN INTEREST ON THE
RECORDS OF SUCH DEPOSITARY AND EACH BENEFICIAL OWNER THAT HOLDS THROUGH SUCH
PARTICIPANT) AGREES FOR THE BENEFIT OF THE COMPANY THAT (A) ANY BENEFICIAL
INTEREST IN THE SECURITIES AND THE COMMON STOCK ISSUABLE UPON THE CONVERSION
THEREOF MAY BE OFFERED, RESOLD, PLEDGED OR OTHERWISE TRANSFERRED, ONLY (I)
INSIDE THE UNITED STATES TO A PERSON WHOM THE SELLER REASONABLY BELIEVES IS A
QUALIFIED INSTITUTIONAL BUYER (AS DEFINED IN RULE 144A UNDER THE SECURITIES ACT)
IN A TRANSACTION MEETING THE REQUIREMENTS OF RULE 144A, (II) OUTSIDE THE UNITED
STATES IN AN OFFSHORE TRANSACTION IN ACCORDANCE WITH RULE 904 UNDER THE
SECURITIES ACT, (III) PURSUANT TO AN EXEMPTION FROM REGISTRATION UNDER THE
SECURITIES ACT PROVIDED BY RULE 144 THEREUNDER (IF AVAILABLE) OR (IV) PURSUANT
TO AN EFFECTIVE REGISTRATION STATEMENT UNDER THE 


                                       16
   24

SECURITIES ACT, IN EACH OF CASES (I) THROUGH (IV) IN ACCORDANCE WITH ANY
APPLICABLE SECURITIES LAWS OF ANY STATE OF THE UNITED STATES, AND (B) THE
BENEFICIAL OWNER WILL, AND EACH SUBSEQUENT BENEFICIAL OWNER OF THIS SECURITY OR
ANY SHARES OF COMMON STOCK ISSUABLE UPON CONVERSION THEREOF IS REQUIRED TO,
NOTIFY ANY PURCHASER OF ANY BENEFICIAL INTEREST IN THE SECURITIES AND ANY SHARES
OF COMMON STOCK ISSUABLE UPON CONVERSION THEREOF FROM IT OF THE RESALE
RESTRICTIONS REFERRED TO IN (A) ABOVE.]

            [INCLUDE IF SECURITY IS A GLOBAL SECURITY:

            THIS SECURITY IS A GLOBAL SECURITY WITHIN THE MEANING OF THE
INDENTURE HEREINAFTER REFERRED TO AND IS REGISTERED IN THE NAME OF A DEPOSITARY
OR A NOMINEE THEREOF. THIS SECURITY MAY NOT BE EXCHANGED IN WHOLE OR IN PART FOR
SECURITY REGISTERED, AND NO TRANSFER OF THIS SECURITY IN WHOLE OR IN PART MAY BE
REGISTERED, IN THE NAME OF ANY PERSON OTHER THAN SUCH DEPOSITARY OR A NOMINEE
THEREOF, EXCEPT IN THE LIMITED CIRCUMSTANCES DESCRIBED IN THE INDENTURE.

            UNLESS THIS CERTIFICATE IS PRESENTED BY AN AUTHORIZED REPRESENTATIVE
OF THE DEPOSITORY TRUST COMPANY, A NEW YORK CORPORATION ("DTC"), 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
IN SUCH OTHER NAME AS IS REQUESTED BY AN AUTHORIZED REPRESENTATIVE OF DTC, AND
ANY PAYMENT IS MADE TO CEDE & CO. OR TO SUCH OTHER ENTITY AS IS 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 BECAUSE THE REGISTERED OWNER
HEREOF, CEDE & CO., HAS AN INTEREST HEREIN.]

            [INCLUDE IF SECURITY IS A DEFINITIVE SECURITY TO BE HELD BY AN
INSTITUTIONAL ACCREDITED INVESTOR:

            IN CONNECTION WITH ANY TRANSFER, THE HOLDER WILL DELIVER TO THE
REGISTRAR AND TRANSFER AGENT SUCH CERTIFICATES AND OTHER INFORMATION AS SUCH
TRANSFER AGENT MAY REASONABLY REQUIRE TO CONFIRM THAT THE TRANSFER COMPLIES WITH
THE FOREGOING RESTRICTIONS.]


                                       17
   25

                             SPACEHAB, Incorporated

                   8% Convertible Subordinated Notes due 2007

No. _______                                                        U.S.$________

[IF RESTRICTED GLOBAL SECURITY - CUSIP No. 846243 AA 1]
[IF DEFINITIVE SECURITY - CUSIP No. 846243 AB 9]

            SPACEHAB, Incorporated, a corporation duly organized and existing
under the laws of the State Washington (herein called the "Company", which term
includes any successor Person under the Indenture hereinafter referred to), for
value received, hereby promises to pay to _______________________________, or
registered assigns, the principal sum of ______________________________ United
States Dollars (U.S.$__________________) on October 15, 2007, and to pay
interest thereon from October 21, 1997, or from the most recent Interest Payment
Date to which interest has been paid or duly provided for, semi-annually on
April 15 and October 15 in each year, commencing April 15, 1998, at the rate of
8% per annum, until the principal hereof is paid or made available for payment.
The interest so payable, and punctually paid or duly provided for, on any
Interest Payment Date will, as provided in such Indenture, be paid to the Person
in whose name this Security (or one or more Predecessor Securities) is
registered at the close of business on the Regular Record Date for such
interest, which shall be the April 1 or October 1 (whether or not a Business
Day), as the case may be, next preceding such Interest Payment Date. Any such
interest not so punctually paid or duly provided for will forthwith cease to be
payable to the Holder on such Regular Record Date and may either be paid to the
Person in whose name this Security (or one or more Predecessor Securities) is
registered at the close of business on a Special Record Date for the payment of
such Defaulted Interest to be fixed by the Trustee, notice whereof shall be
given to Holders of Securities not less than 10 days prior to such Special
Record Date, or be paid at any time in any other lawful manner not inconsistent
with the requirements of any securities exchange on which the Securities may be
listed, and upon such notice as may be required by such exchange, all as more
fully provided in said Indenture.

            Payment of the principal of, premium, if any, and interest
(including payment of any Additional Interest) on this Security will be made at
the Corporate Trust Office, in such coin or currency of the United States of
America as at the time of payment is legal tender for payment of public and
private debts by a U.S. Dollar check drawn on an account maintained with a bank
in the Borough of Manhattan, The City of New York or Richmond, Virginia;
provided, however, that upon written application by the Holder to the Security
Registrar setting forth wire instructions not later than 15 days prior to the
relevant payment date (in the case of payment of principal) or not later than
the relevant Record Date (in the case of payment of interest), such Holder may
receive payment by wire transfer of Dollars to a U.S. Dollar account (such
transfers to be made only to Holders of an aggregate principal amount in excess
of U.S.$2,000,000) maintained by the payee with a bank in the United States or
in Europe and designated by the payee to the Security Registrar.


                                       18
   26

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

            Unless the certificate of authentication hereon has been executed by
the Trustee referred to on the reverse hereof by manual signature, this Security
shall not be entitled to any benefit under the Indenture or be valid or
obligatory for any purpose.

            IN WITNESS WHEREOF, the Company has caused this instrument to be
duly executed under its corporate seal.

Dated:

                                        SPACEHAB, INCORPORATED


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

Attest:


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

            SECTION 2.03. Form of Reverse of Security. This Security is one of a
duly authorized issue of Securities of the Company designated as its 8%
Convertible Subordinated Notes due 2007 (herein called the "Securities"),
limited in aggregate principal amount to U.S.$55,000,000 (subject to increase as
provided in the Indenture herein defined up to an additional U.S.$8,250,000
aggregate principal amount), issued and to be issued under an Indenture, dated
as of October 15, 1997 (herein called the "Indenture"), between the Company and
First Union National Bank, as Trustee for the Holders of Securities issued under
said Indenture (herein called the "Trustee", which term includes any successor
trustee under the Indenture), to which Indenture and all indentures supplemental
thereto reference is hereby made for a statement of the respective rights,
limitations of rights, duties and immunities thereunder of the Company, the
Trustee, the holders of Senior Indebtedness and the Holders of the Securities
and of the terms upon which the Securities are, and are to be, authenticated and
delivered.

            Subject to and upon compliance with the provisions of the Indenture,
the Holder of this Security is entitled, at his option, at any time on or before
the close of business on the Business Day immediately preceding October 15,
2007, or in case this Security or a portion hereof is called for redemption,
then in respect of this Security or such portion hereof until and including, but
(unless the Company defaults in making the payment due upon redemption or
repurchase) not after, the close of business on the Business Day immediately
preceding the Redemption Date or Repurchase Date, as the 


                                       19
   27

case may be, to convert this Security (or any portion of the principal amount
hereof which is U.S.$1,000 or an integral multiple thereof), at the principal
amount hereof, or of such portion, into fully paid and non-assessable shares of
Common Stock of the Company at a conversion price equal to U.S.$13.625 aggregate
principal amount of Securities for each share of Common Stock (or at the current
adjusted conversion price if an adjustment has been made as provided in Article
XIII of the Indenture) by surrender of this Security, duly endorsed or assigned
to the Company or in blank, to the Company at its office or agency in the
Borough of Manhattan, The City of New York or Richmond, Virginia, accompanied by
the conversion notice hereon executed by the Holder hereof evidencing such
Holder's election to convert this Security, or if less than the entire principal
amount hereof is to be converted, the portion hereof to be converted, and, in
case such surrender shall be made during the period from the close of business
on any Regular Record Date to the opening of business on the corresponding
Interest Payment Date (unless this Security or the portion hereof being
converted has been called for redemption on a Redemption Date within such period
between and including such Regular Record Date and such Interest Payment Date),
also accompanied by payment in funds acceptable to the Company of an amount
equal to the interest payable on such Interest Payment Date on the principal
amount of this Security then being converted. Subject to the aforesaid
requirement for payment of interest and, in the case of a conversion after the
close of business on any Regular Record Date and on or before the corresponding
Interest Payment Date, to the right of the Holder of this Security (or any
Predecessor Security) of record at such Regular Record Date to receive an
installment of interest (even if the Security has been called for redemption on
a Redemption Date within such period), no payment or adjustment is to be made on
conversion for interest accrued hereon or for dividends on the Common Stock
issued on conversion. No fractions of shares or scrip representing fractions of
shares will be issued on conversion, but instead of any fractional interest the
Company shall pay a cash adjustment or round up to the next higher whole share
as provided in Article XIII of the Indenture. The conversion price is subject to
adjustment as provided in Article XIII of the Indenture. In addition, the
Indenture provides that in case of certain reclassifications, consolidations,
mergers, sales or transfers of assets or other transactions pursuant to which
the Common Stock is converted into the right to receive other securities, cash
or other property, the Indenture shall be amended, without the consent of any
Holders of Securities, so that this Security, if then outstanding, will be
convertible thereafter, during the period this Security shall be convertible as
specified above, only into the kind and amount of securities, cash and other
property receivable upon the transaction by a holder of the number of shares of
Common Stock into which this Security might have been converted immediately
prior to such transaction (assuming such holder of Common Stock failed to
exercise any rights of election and received per share the kind and amount
received per share by a plurality of non-electing shares).

            The Company will furnish to any Holder, upon request and without
charge, copies of the Certificate of Incorporation and By-laws of the Company
then in effect. Any such request may be addressed to the Company or to the
Security Registrar.

            The Securities are subject to redemption at the option of the
Company upon not less than 20 days' or more than 40 days' notice by mail, at any
time on or after 


                                       20
   28

October 20, 2000 through October 14, 2001 at 105.3333% of the principal amount,
and thereafter, as a whole or from time to time in part, at the following
Redemption Prices (expressed as percentages of the principal amount), if
redeemed during the 12-month period beginning on October 15 of the years
indicated,

                                           Redemption
                         Year                Price
                         ----              ----------

                         2001............. 104.4444%
                         2002............. 103.5556%
                         2003............. 102.6667%
                         2004............. 101.7778%
                         2005............. 100.8889%
                   
; and thereafter at a Redemption Price equal to 100% of the principal amount,
together in the case of any such redemption with accrued interest to (but not
including) the Redemption Date, but interest installments whose Stated Maturity
is on or prior to such Redemption Date will be payable to the Holders of such
Securities, or one or more Predecessor Securities, of record at the close of
business on the relevant Record Dates referred to on the face hereof, all as
provided in the Indenture.

            In certain circumstances involving a Change in Control, each Holder
shall have the right to require the Company to redeem all or part of its
Securities at a repurchase price equal to 100% of the principal amount thereof,
together with accrued and unpaid interest through the Repurchase Date.

            The Securities do not have the benefit of any sinking fund.

            In the event of redemption, conversion or repurchase of this
Security in part only, a new Security or Securities for the unredeemed,
unconverted or unrepurchased portion hereof will be issued in the name of the
Holder hereof upon the cancellation hereof.

            Subject to certain limitations in the Indenture, at any time when
the Company is not subject to Section 13 or 15(d) of the United States
Securities Exchange Act of 1934, as amended, upon the request of a Holder or the
holder of shares of Common Stock issued upon conversion thereof, the Company
will promptly furnish or cause to be furnished Rule 144A Information (as defined
below) to such Holder or such holder of shares of Common Stock issued upon
conversion, or to a prospective purchaser of any such security designated by any
such Holder or holder of shares of Common Stock, as the case may be, to the
extent required to permit compliance by such Holder or holder of shares of
Common Stock with Rule 144A under the United States Securities Act of 1933, as
amended (the "Securities Act"), in connection with the resale of any such
security. "Rule 144A Information" shall be such information as is specified
pursuant to Rule 144A(d)(4) under the Securities Act (or any successor provision
thereto).


                                       21
   29

            If this Security is a Transfer Restricted Security, then the Holder
of this Security [IF THIS SECURITY IS A GLOBAL SECURITY, THEN INSERT-including
any Person that has a beneficial interest in this Security)] and the Common
Stock issuable upon conversion thereof is entitled to the benefits of a
Registration Rights Agreement, dated as of October 15, 1997 (the "Registration
Rights Agreement") executed by the Company. If a Registration Default occurs (as
defined in the Registration Rights Agreement and in the Indenture), Additional
Interest will accrue on this Security from and including the day following such
Registration Default to but excluding the day on which such Registration Default
has been cured. Additional Interest will be paid semi-annually in arrears, with
the first semi-annual payment due on the first Interest Payment Date in respect
of the Securities following the date on which such Additional Interest begins to
accrue, and will accrue at a rate per annum equal to an additional one-half of
one percent (0.50%) of the principal amount of the Securities.

            Whenever in this Security there is a reference, in any context, to
the payment of the principal of, premium, if any, or interest on, or in respect
of, any Security, such mention shall be deemed to include mention of the payment
of Additional Interest payable as described in the preceding paragraph to the
extent that, in such context, Additional Interest is, was or would be payable in
respect of such Security and express mention of the payment of Additional
Interest (if applicable) in any provisions of this Security shall not be
construed as excluding Additional Interest in those provisions of this Security
where such express mention is not made.

            The indebtedness evidenced by this Security is, to the extent
provided in the Indenture, subordinate and subject in right of payment to the
prior payment in full of all Senior Indebtedness, and this Security is issued
subject to the provisions of the Indenture with respect thereto. Each Holder of
this Security, by accepting the same, (a) agrees to and shall be bound by such
provisions, (b) authorizes and directs the Trustee on his behalf to take such
action as may be necessary or appropriate to effectuate the subordination so
provided and (c) appoints the Trustee his attorney-in-fact for any and all such
purposes.

            If an Event of Default shall occur and be continuing, the principal
of all the Securities may be declared due and payable in the manner and with the
effect provided in Article V of the Indenture.

            The Indenture permits, with certain exceptions as therein provided,
the amendment thereof and the modification of the rights and obligations of the
Company and the rights of the Holders of the Securities under the Indenture at
any time by the Company and the Trustee with the consent of the Holders of a
majority in aggregate principal amount of the Securities at the time
Outstanding. The Indenture also contains provisions permitting the Holders of a
majority in aggregate principal amount of the Securities at the time
Outstanding, on behalf of the Holders of all the Securities, to waive compliance
by the Company with certain provisions of the Indenture and certain past
defaults under the Indenture and their consequences. Any such consent or waiver
by the Holder of this Security shall be conclusive and binding upon such Holder
and upon all future Holders of this Security and of any Security issued upon the
registration of transfer 


                                       22
   30

hereof or in exchange hereof or in lieu hereof, whether or not notation of such
consent or waiver is made upon this Security.

            No reference herein to the Indenture and no provision of this
Security or of the Indenture shall alter or impair the obligation of the
Company, which is absolute and unconditional, to pay the principal of, premium,
if any, and interest on (including Additional Interest) this Security at the
times, place and rate, and in the coin or currency, herein prescribed or to
convert this Security as provided in the Indenture.

            As provided in the Indenture and subject to certain limitations
therein set forth, the transfer of this Security is registrable in the Security
Register, upon surrender of this Security for registration of transfer at the
Corporate Trust Office duly endorsed by, or accompanied by a written instrument
of transfer in form satisfactory to the Company and the Security Registrar duly
executed by, the Holder hereof or his attorney duly authorized in writing, and
thereupon one or more new Securities, of authorized denominations and for the
same aggregate principal amount, will be issued to the designated transferee or
transferees.

            The Securities are issuable only in registered form without coupons
in denominations of U.S.$l,000 (or, in the case of Definitive Securities sold to
Institutional Accredited Investors, minimum denominations of U.S.$250,000) and
any integral multiple thereof. As provided in the Indenture and subject to
certain limitations therein set forth, Securities are exchangeable for a like
aggregate principal amount of Securities of a different authorized denomination,
as requested by the Holder surrendering the same.

            No service charge shall be made for any such registration of
transfer or exchange, but the Company may require payment of a sum sufficient to
cover any tax or other governmental charge payable in connection therewith.

            Prior to due presentment of this Security for registration of
transfer, the Company, the Trustee and any agent of the Company or the Trustee
may treat the Person in whose name this Security is registered as the owner
hereof for all purposes, whether or not payment of or on this Security is
overdue, and neither the Company, the Trustee nor any such agent shall be
affected by notice to the contrary.

            Interest on this Security shall be computed on the basis of a
360-day year of twelve 30-day months.

            All terms used in this Security which are defined in the Indenture
shall have the meanings assigned to them in the Indenture.

            THE INDENTURE AND THIS SECURITY SHALL BE GOVERNED BY AND CONSTRUED
IN ACCORDANCE WITH THE LAWS OF THE STATE OF NEW YORK.


                                       23
   31

            SECTION 2.04. Form of Trustee's Certificate of Authentication.

            This is one of the Securities referred to in the within-mentioned
Indenture.

Dated:                                       ______________________, as Trustee


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

            SECTION 2.05. Form of Conversion Notice.

                                CONVERSION NOTICE

To: SPACEHAB, Incorporated

            The undersigned Holder of this Security hereby irrevocably exercises
the option to convert this Security, or the portion hereof (which is U.S.$1,000
or an integral multiple thereof) below designated, at any time following the
date of original issuance thereof, into shares of Common Stock in accordance
with the terms of the Indenture referred to in this Security, and directs that
the shares issuable and deliverable upon conversion, together with any check in
payment for a fractional share and any Security representing any unconverted
principal amount hereof, be issued and delivered to the registered owner hereof
unless a different name has been provided below. If shares or any portion of
this Security not converted are to be issued in the name of a person other than
the undersigned, the undersigned will pay all transfer taxes payable with
respect thereto and is delivering herewith a certificate in proper form
certifying that the applicable restrictions on transfer have been complied with.
Any amount required to be paid by the undersigned on account of interest
accompanies this Security.

            The Applicant hereby agrees that, promptly after request of the
Company, he or it will furnish such proof in support of this certification as
the Company or the Security Registrar for the Common Stock may, from time to
time, request.


                                       24
   32

Dated:


                                                --------------------------------
                                                           Signature*

If shares or Securities are to be               Principal amount to be converted
registered in the name of a Person              (if less than all):             
other than the Holder, please                   $___________,000                
print such Person's name and                    
address:*                                   

- ------------------------------------         -----------------------------------
               Name                                 Social Security or 
- ------------------------------------           Taxpayer Identification Number
         Street Address
- ------------------------------------
    City, State and Zip Code

* Signature(s) must be guaranteed by an eligible guarantor institution (banks,
stock brokers, savings and loan associations and credit unions with membership
in an approved signature guarantee medallion program) pursuant to Securities and
Exchange Commission Rule 17Ad-l5 if shares of Common Stock are to be delivered,
or unconverted Securities are to be issued, other than to and in the name of the
registered owner.

            SECTION 2.06. Form of Certification. Whenever any certification is
required to be given to evidence compliance with certain restrictions relating
to transfers of Restricted Securities contemplated by Section 3.05(b)(iv),
Section 3.05(c) or Section 13.02, such certification shall be provided
substantially in the form of the following certificate, with only such changes
as shall be approved by the Company and the Initial Purchasers,

                              TRANSFER CERTIFICATE

            The undersigned Holder hereby certifies with respect to U.S.$______
principal amount of the above-captioned securities presented or surrendered on
the date hereof (the "Surrendered Securities") for registration of transfer, or
for exchange or conversion where the securities issuable upon such exchange or
conversion are to be registered in a name other than that of the undersigned
Holder (each such transaction being a "transfer"), that such transfer complies
with the restrictive legend set forth on the face of the Surrendered Securities
for the reason checked below:

____________      The transfer of the Surrendered Securities complies with Rule
                  144 under the U.S. Securities Act of 1933, as amended (the
                  "Securities Act"); or


                                       25
   33

____________      The transfer of the Surrendered Securities complies with Rule
                  144A under the Securities Act; or

____________      The transfer of the Surrendered Securities complies with Rule
                  904 of Regulation S under the Securities Act; or

____________      The transfer of the Surrendered Securities is pursuant to an
                  effective registration statement under the Securities Act, the
                  prospectus delivery requirements under the Securities Act have
                  been satisfied with respect to such transfer, the undersigned
                  Holder is named as a "Selling Securityholder" in the
                  prospectus relating to such registration statement, or in
                  amendments or supplements thereto, and the aggregate principal
                  amount of Surrendered Securities transferred are all or a
                  portion of the securities listed in such prospectus opposite
                  the undersigned's name.

Dated: _____________*
 * To be dated the date of surrender.


                                              ----------------------------------
                                                         Signature

                                              (If the registered owner is a   
                                              corporation, partnership or     
                                              fiduciary, the title of the     
                                              Person signing on behalf of such
                                              registered owner must be        
                                              stated.)                        

                                   ARTICLE III

                                 The Securities

            SECTION 3.01. Title and Terms; Issuable in Series. The aggregate
principal amount of Securities which may be authenticated and delivered under
this Indenture is limited to (a) U.S.$55,000,000 plus (b) such aggregate
principal amount (which may not exceed U.S.$7,500,000 principal amount) of
Securities as may be purchased by the Initial Purchasers on the Second Closing
Date pursuant to the Purchase Agreement, dated October 15, 1997, between the
Company and the Initial Purchasers, except for Securities authenticated and
delivered upon registration of transfer of, or in exchange for, or in lieu of,
other Securities of the series pursuant to Sections 3.04, 3.05, 3.06, 9.06,
11.08, 13.02 or 14.05 and except for Securities which, pursuant to Section 3.03,
are deemed never to have been authenticated and delivered hereunder.

            The Stated Maturity of the Securities shall be October 15, 2007, and
they shall bear interest at the rate of 8% per annum, payable semi-annually on
April 15 and October 15, commencing April 15, 1998, until the principal thereof
is paid or made available for payment.


                                       26
   34

            Payment of the principal of, premium, if any, and interest
(including payment of any Additional Interest) on this Security will be made at
the Corporate Trust Office, in such coin or currency of the United States of
America as at the time of payment is legal tender for payment of public and
private debts by a U.S. Dollar check drawn on an account maintained with a bank
in the Borough of Manhattan, The City of New York or Richmond, Virginia;
provided, however, that upon written application by the Holder to the Security
Registrar setting forth wire instructions not later than 15 days prior to the
relevant payment date (in the case of payment of principal) or not later than
the relevant Record Date (in the case of payment of interest), such Holder may
receive payment by wire transfer of Dollars to a U.S. Dollar account (such
transfers to be made only to Holders of an aggregate principal amount in excess
of U.S.$2,000,000) maintained by the payee with a bank in the United States or
in Europe and designated by the payee to the Security Registrar.

            The Securities shall be redeemable by the Company as provided in
Article XI.

            The Securities shall be subordinated in right of payment to the
prior payment in full of Senior Indebtedness as provided in Article XII.

            The Securities shall be convertible as provided in Article XIII.

            The Securities shall be subject to purchase by the Company at the
option of the Holder as provided in Article XIV.

            SECTION 3.02. Denominations. The Securities shall be issuable only
in registered form without coupons and only in denominations of U.S.$1,000 and
any integral multiple thereof.

            SECTION 3.03. Execution, Authentication, Delivery and Dating. The
Securities shall be executed on behalf of the Company by any of its Chairman of
the Board, its Vice Chairman of the Board, its President or one of its Vice
Presidents, under its corporate seal reproduced thereon and attested by its
Secretary or one of its Assistant Secretaries. The signature of any of these
officers on the Securities may be manual or facsimile.

            Securities bearing the manual or facsimile signatures of individuals
who were at any time the proper officers of the Company shall bind the Company,
notwithstanding that such individuals or any of them have ceased to hold such
offices prior to the authentication and delivery of such Securities or did not
hold such offices at the date of such Securities.

            At any time and from time to time after the execution and delivery
of this Indenture, the Company may deliver Securities of any series executed by
the Company to the Trustee for authentication, together with a Company Order for
the authentication and delivery of such Securities; and the Trustee in
accordance with such Company Order shall authenticate and deliver such
Securities as in this Indenture provided and not otherwise.


                                       27
   35

            Each Security shall be dated the date of its authentication.

            No Security shall be entitled to any benefit under this Indenture or
be valid or obligatory for any purpose unless there appears on such Security a
certificate of authentication substantially in the form provided for herein
executed by the Trustee by manual signature, and such certificate upon any
Security shall be conclusive evidence, and the only evidence, that such Security
has been duly authenticated and delivered hereunder.

            SECTION 3.04. Global and Non-Global Securities.

            (a) Global Securities.

            (i) Each Global Security authenticated under this Indenture shall be
registered in the name of the Depositary designated by the Company for such
Global Security or a nominee thereof and delivered to such Depositary or a
nominee thereof or custodian therefor, and each such Global Security shall
constitute a single Security for all purposes, of this Indenture.

            (ii) Notwithstanding any other provision in this Indenture, no
Global Security may be exchanged in whole or in part for Securities registered,
and no transfer of a Global Security in whole or in part may be registered, in
the name of any Person other than the Depositary for such Global Security or a
nominee thereof unless (A) such Depositary (1) has notified the Company that it
is unwilling or unable to continue as Depositary for such Global Security or (2)
has ceased to be a clearing agency registered as such under the Exchange Act or
announces an intention permanently to cease business or does in fact do so, (B)
there shall have occurred and be continuing an Event of Default with respect to
such Global Security, or (C) the Company in its discretion at any time
determines not to have all the Securities represented by a Global Security. Any
Global Security exchanged pursuant to clause (i) above shall be so exchanged in
whole and not in part and any Global Security exchanged pursuant to clause (ii)
or (iii) above may be exchanged in whole or from time to time in part as
directed by the Depositary. Any Security issued in exchange for a Global
Security or any portion thereof shall be a Global Security; provided that any
such Security so issued that is registered in the name of a Person other than
the Depositary or a nominee thereof shall not be a Global Security. 

            (iii) If any Global Security is to be exchanged for other Securities
or canceled in whole, it shall be surrendered by or on behalf of the Depositary
or its nominee to the Trustee, as Security Registrar, for exchange or
cancellation as provided in this Article Three. If any Global Security is to be
exchanged for other Securities or cancelled in part, or if another Security is
to be exchanged in whole or in part for a beneficial interest in any Global
Security, in each case, as provided in Section 3.05, then either (i) such Global
Security shall be so surrendered for exchange or cancellation as provided in
this Article III or (ii) the principal amount thereof shall be reduced or
increased by an amount equal to the portion thereof to be so exchanged or
cancelled, or equal to the principal amount of such other Security to be so
exchanged for a beneficial interest therein, as the case may be, by means of an
appropriate adjustment made on the 


                                       28
   36

records of the Trustee, as Security Registrar, whereupon the Trustee, in
accordance with the Applicable Procedures, shall instruct the Depositary or its
authorized representative to make a corresponding adjustment to its records.
Upon any such surrender or adjustment of a Global Security, the Trustee shall,
subject to Section 3.05(c) and as otherwise provided in this Article III,
authenticate and deliver any Securities issuable in exchange for such Global
Security (or any portion thereof) to or upon the order of, and registered in
such names as may be directed by, the Depositary or its authorized
representative. Upon the request of the Trustee in connection with the
occurrence of any of the events specified in the preceding paragraph, the
Company shall promptly make available to the Trustee a reasonable supply of
Securities that are not in the form of Global Securities. The Trustee shall be
entitled to rely upon any order, direction or request of the Depositary or its
authorized representative which is given or made pursuant to this Article III if
such order, direction or request is given or made in accordance with the
Applicable Procedures.

            (iv) Every Security authenticated and delivered upon registration of
transfer of, or in exchange for or in lieu of, a Global Security or any portion
thereof, whether pursuant to this Article III or otherwise, shall be
authenticated and delivered in the form of, and shall be, a Global Security,
unless such Security is registered in the name of a Person other than the
Depositary for such Global Security or a nominee thereof, in which case such
Security shall be authenticated and delivered in definitive, fully registered
form, without interest coupons.

            (v) The Depositary or its nominee, as registered owner of a Global
Security, shall be the Holder of such Global Security for all purposes under the
Indenture and the Securities, and owners of beneficial interests in a Global
Security shall hold such interests pursuant to the Applicable Procedures.
Accordingly, any such owner's beneficial interest in a Global Security will be
shown only on, and the transfer of such interest shall be effected only through,
records maintained by the Depositary or its nominee or its Agent Members and
such owners of beneficial interests in a Global Security will not be considered
the owners or holders thereof. Notwithstanding the foregoing, nothing herein
shall prevent the Company, the Trustee or any agent of the Company or the
Trustee from giving effect to any written certification, proxy or other
authorization furnished by the Depositary or such nominee, as the case may be,
or impair, as between the Depositary, its Agent Members and any other person on
whose behalf an Agent Member may act, the operation of customary practices of
such Persons governing the exercise of the rights of a holder of any Security.

            (b) Non-Global Securities.

            (i) Securities issued pursuant to Regulation D under the Securities
Act shall be initially issued as Securities in definitive, fully registered
form, without interest coupons, shall initially be registered in such names and
be in such authorized denominations as the Initial Purchasers shall designate
and shall bear the legends required hereunder. The Company will make available
to the Trustee a reasonable supply of Securities in definitive form.


                                       29
   37

            (ii) Pending the preparation of definitive Securities, the Company
may execute, and upon Company Order the Trustee shall authenticate and deliver,
temporary Securities which are printed, lithographed, typewritten, mimeographed
or otherwise produced, in any authorized denomination, substantially of the
tenor of the definitive Securities in lieu of which they are issued and with
such appropriate insertions, omissions, substitutions and other variations as
the officers executing such Securities may determine, as evidenced by their
execution of such Securities. 

            If temporary Securities are issued, the Company will cause
definitive Securities to be prepared without unreasonable delay. After the
preparation of definitive Securities, the temporary Securities shall be
exchangeable for definitive Securities upon surrender of the temporary
Securities at any office or agency of the Company designated pursuant to Section
10.02, without charge to the Holder. Upon surrender for cancellation of any one
or more temporary Securities the Company shall execute and the Trustee shall
authenticate and deliver in exchange therefor a like principal amount of
definitive Securities of authorized denominations. Until so exchanged, the
temporary Securities shall in all respects be entitled to the same benefits
under this Indenture as definitive Securities.

            SECTION 3.05. Registration; Registration of Transfer and Exchange.
(a) The Company shall cause to be kept at the Corporate Trust Office of the
Trustee a register (the register maintained in such office and in any other
office or agency designated pursuant to Section 10.02 being herein sometimes
collectively referred to as the "Security Register") in which, subject to such
reasonable regulations as it may prescribe, the Company shall provide for the
registration of Securities and of transfers and exchanges thereof. The Trustee
is hereby appointed "Security Registrar" for the purpose of registering
Securities and transfers and exchanges thereof as herein provided. Upon
surrender for registration of transfer or exchange of any Security at an office
or agency of the Company designated pursuant to Section 10.02 for such purpose,
accompanied by a written instrument of transfer or exchange in the form provided
by the Company, the Company shall execute, and the Trustee shall authenticate
and deliver, in the name of the designated transferee or transferees, one or
more new Securities of the same series, of any authorized denominations and of a
like aggregate principal amount.

            (b) Notwithstanding any other provisions of this Indenture or the
Securities, transfers and exchanges of Securities and beneficial interests in a
Global Security of the kinds specified in this Section 3.05(b) shall be made
only in accordance with this Section 3.05(b).

            (i) Transfer of Global Security. Other than as set forth in Section
3.04(a), a Global Security may not be transferred, in whole or in part, to any
Person other than the Depositary or a nominee thereof, and no such transfer to
any such other Person may be registered; provided that this Section 3.05(b)(i)
shall not prohibit any transfer of a Security that is issued in exchange for a
Global Security but is not itself a Global Security. No transfer of a Security
to any Person shall be effective under this Indenture or the Securities unless
and until such Security has been registered in the name of such Person. Nothing
in this Section 3.05(b)(i) shall prohibit or render ineffective any transfer 


                                       30
   38

of a beneficial interest in a Global Security effected in accordance with the
other provisions of this Section 3.05(b).

            (ii) Transfer of Beneficial Interests in thc Global Security.
Transfer of beneficial interests in the Global Security shall be effected
through the Depositary, in accordance with this Indenture (including applicable
restrictions on transfer set forth herein, if any) and the procedures of the
Depositary therefor, if applicable.

            (iii) Other Exchanges. In the event that a Global Security or any
portion thereof is exchanged for Securities other than Global Securities, such
other Securities may in turn be exchanged (on transfer or otherwise) for
Securities that are not Global Securities or for beneficial interests in a
Global Security (if any is then outstanding) only in accordance with such
procedures, which shall be substantially consistent with the provisions of
Section 3.05(b) (including the certification requirements set forth on the
reverse of the Security intended to insure that transfers of beneficial
interests in a Global Security comply with Rule 144A, Regulation S or Rule 144
under the Securities Act, as the case may be) and any Applicable Procedures, as
may be from time to time adopted by the Company and the Trustee.

            (iv) Transfer and Exchange of Definitive Securities. When Definitive
Securities are presented to the Security Registrar with a request:

                  (A) to register the transfer of such Definitive Securities; or

                  (B) to exchange such Definitive Securities for an equal
            principal amount of Definitive Securities of other authorized
            denominations, the Security Registrar shall register the transfer or
            make the exchange as requested if its reasonable requirements for
            such transaction are met; provided, however, that the Definitive
            Securities surrendered for transfer or exchange: 

                        (x) shall be duly endorsed or accompanied by a written
                  instrument of transfer in form reasonably satisfactory to the
                  Company and the Security Registrar, duly executed by the
                  Holder thereof or his attorney duly authorized in writing; and

                        (y) are being transferred or exchanged pursuant to an
                  effective registration statement under the Securities Act,
                  pursuant to Section 3.05(b)(v), or pursuant to clause (1), (2)
                  or (3) below, and are accompanied by the following additional
                  information and documents, as applicable:

                              (1) if such Definitive Securities are being
                        delivered to the Security Registrar by a Holder for
                        registration in the name of such Holder, without
                        transfer, a certification from such Holder to that
                        effect (in the form set forth in Section 2.06); or


                                       31
   39

                              (2) if such Definitive Securities are being
                        transferred to the Company, a certification to that
                        effect (in the form set forth in Section 2.06); or

                              (3) if such Definitive Securities are being
                        transferred pursuant to an exemption from registration
                        in accordance with Rule 144, (i) a certification to that
                        effect (in the form set forth in Section 2.06) and (ii)
                        if the Company or Security Registrar so requests, an
                        opinion of counsel or other evidence reasonably
                        satisfactory to them as to the compliance with the
                        restrictions set forth in the legend set forth in
                        Section 2.02.

            (v) Restrictions on Transfer of a Definitive Security for a
Beneficial Interest in a Global Security. A Definitive Security may not be
exchanged for a beneficial interest in a Global Security except upon
satisfaction of the requirements set forth below. Upon receipt by the Trustee of
a Definitive Security, duly endorsed or accompanied by appropriate instruments
of transfer, in form satisfactory to the Trustee, together with:

                  (A) certification in the form set forth on the reverse of the
            Security (1) that such Definitive Security is being transferred to a
            Qualified Institutional Buyer in accordance with Rule 144A or (2)
            outside the United States in an offshore transaction within the
            meaning of Regulation S and in compliance with Rule 904 under the
            Securities Act; and

                  (B) written instructions directing the Trustee to make, or to
            direct the Securities Registrar to make, an adjustment on its books
            and records with respect to such Global Security to reflect an
            increase in the aggregate principal amount of the Securities
            represented by the Global Security, such instructions to contain
            information regarding the Depositary account to be credited with
            such increase, 

      then the Trustee shall cancel such Definitive Security and cause, or
      direct the Securities Registrar to cause, in accordance with the standing
      instructions and procedures existing between the Depository and the
      Securities Registrar, the aggregate principal amount of Securities
      represented by the Global Security to be increased by the aggregate
      principal amount of the Definitive Security to be exchanged and shall
      credit or cause to be credited to the account of the Person specified in
      such instructions a beneficial interest in the Global Security equal to
      the principal amount of the Definitive Security so cancelled. If no Global
      Securities are then outstanding, the Company shall issue and the Trustee
      shall authenticate, upon written order of the Company in the form of an
      Officers' Certificate, a new Global Security in the appropriate principal
      amount.


                                       32
   40

            (c) Subject to the succeeding paragraph, every Security shall be
subject to the restrictions on transfer provided in the legends required by
Section 2.02 to be applied to such Security. Whenever any Security is presented
or surrendered for registration of transfer or for exchange for a Security
registered in a name other than that of the Holder, such Security must be
accompanied by a certificate in substantially the form set forth in Section
2.06, dated the date of such surrender and signed by the Holder of such
Security, as to compliance with such restrictions on transfer. The Security
Registrar shall not be required to accept for such registration of transfer or
exchange any Security not so accompanied by a properly completed certificate.

            (d) The restrictions imposed by the legend set forth in the first or
fourth paragraph, as the case may be, of Section 2.02 upon the transferability
of any Security shall cease and terminate when such Security has been sold
pursuant to an effective registration statement under the Securities Act,
transferred in compliance with Rule 144 under the Securities Act (or any
successor provision thereto), or after the second anniversary of the original
issuance date of the Security (or such earlier date after which the Security may
be freely transferred without registration under the Securities Act or without
being subject to transfer restrictions pursuant to the Securities Act, as may be
provided in Rule 144(k) under the Securities Act (or any successor provision
thereto) or otherwise). Any Security as to which such restrictions on transfer
shall have expired in accordance with their terms or shall have terminated may,
upon surrender of such Security for exchange to the Security Registrar in
accordance with the provisions of this Section 3.05 (accompanied, in the event
that such restrictions on transfer have terminated by reason of a transfer in
compliance with Rule 144 or any successor provision, by an opinion of counsel
having substantial experience in practice under the Securities Act and otherwise
reasonably acceptable to the Company, addressed to the Company and in form
acceptable to the Company, to the effect that the transfer of such Security has
been made in compliance with Rule 144 or such successor provision), be exchanged
for a new Security, of like tenor and aggregate principal amount, which shall
not bear the restrictive legend set forth in the first paragraph of Section
2.02. The Company shall inform the Trustee of the effective date of any
registration statement registering the Securities under the Securities Act. The
Trustee shall not be liable for any action taken or omitted to be taken by it in
good faith in accordance with the aforementioned opinion of counsel or notice of
an effective registration statement. 

            (e) As used in the preceding two paragraphs of this Section 3.05,
the term "transfer" encompasses any sale, pledge, transfer, hypothecation or
other disposition of any Security.

            (f) No service charge shall be made for any registration of transfer
or exchange of Securities, but the Company may require payment of a sum
sufficient to cover any tax or other governmental charge that may be imposed in
connection with any registration of transfer or exchange of Securities, other
than exchanges pursuant to Section 3.04, 9.06, 11.08, 13.02 or 14.05 not
involving any transfer.

            (g) The Company shall not be required (i) to issue, register the
transfer of or exchange any Security during a period beginning at the opening of
business 15 days 


                                       33
   41

before the day of the mailing of a notice of redemption of Securities selected
for redemption under Section 11.04 and ending at the close of business on the
day of such mailing, or (ii) to register the transfer of or exchange any
Security so selected for redemption in whole or in part, except the unredeemed
portion of any Security being redeemed in part.

            SECTION 3.06. Mutilated, Destroyed, Lost and Stolen Securities. If
any mutilated Security is surrendered to the Trustee, the Company shall execute
and the Trustee shall authenticate and deliver in exchange therefor a new
Security of like tenor and principal amount and bearing a number not
contemporaneously outstanding.

            If there shall be delivered to the Company and the Trustee (i)
evidence to their satisfaction of the destruction, loss or theft of any Security
and (ii) such security or indemnity as may be required by them to save each of
them and any agent of either of them harmless, then, in the absence of notice to
the Company or the Trustee that such Security has been acquired by a bona fide
purchaser, the Company shall execute and the Trustee shall authenticate and
deliver, in lieu of any such destroyed, lost or stolen Security, a new Security
of like tenor and principal amount and bearing a number not contemporaneously
outstanding.

            In case any such mutilated, destroyed, lost or stolen Security has
become or is about to become due and payable, the Company in its discretion, but
subject to any conversion rights, may, instead of issuing a new Security, pay
such Security.

            Upon the issuance, authentication and delivery by the Trustee of any
new Security under this Section, the Company may require the payment of a sum
sufficient to cover any tax or other governmental charge that may be imposed in
relation thereto and any other expenses (including the fees and expenses of the
Trustee) connected therewith.

            Every new Security, authenticated and delivered by the Trustee
pursuant to this Section in lieu of any destroyed, lost or stolen Security shall
constitute an original additional contractual obligation of the Company, whether
or not the destroyed, lost or stolen Security shall be at any time enforceable
by anyone, and shall be entitled to all the benefits of this Indenture equally
and proportionately with any and all other Securities duly issued hereunder.

            The provisions of this Section are exclusive and shall preclude (to
the extent lawful) all other rights and remedies with respect to the replacement
or payment of mutilated, destroyed, lost or stolen Securities.

            SECTION 3.07. Payment of Interest; Interest Rights Preserved.
Interest on any Security which is payable, and is punctually paid or duly
provided for, on any Interest Payment Date shall be paid to the Person in whose
name that Security (or one or more Predecessor Securities) is registered at the
close of business on the Regular Record Date for payment of such interest.

            If the Company shall be required by law to deduct any taxes from any
sum of interest payable hereunder to a Holder, (i) the Company shall make such
deductions 


                                       34
   42

and shall pay the full amount deducted to the relevant taxing authority in
accordance with applicable law and (ii) the amount of such deduction shall be
treated for purposes hereof as a payment of interest.

            Any interest on any Security which is payable, but is not punctually
paid or duly provided for, on any Interest Payment Date (herein called
"Defaulted Interest") shall forthwith cease to be payable to the Holder on the
relevant Regular Record Date by virtue of having been such Holder, and such
Defaulted Interest may be paid by the Company, at its election in each case, as
provided in Clause (1) or (2) below:

            (1) The Company may elect to make payment of any Defaulted Interest
      to the Persons in whose names the Securities (or their respective
      Predecessor Securities) are registered at the close of business on a
      Special Record Date for the payment of such Defaulted Interest, which
      shall be fixed in the following manner. The Company shall notify the
      Trustee in writing of the amount of Defaulted Interest proposed to be paid
      on each Security and the date of the proposed payment, and at the same
      time the Company shall deposit with the Trustee an amount of money equal
      to the aggregate amount proposed to be paid in respect of such Defaulted
      Interest or shall make arrangements satisfactory to the Trustee for such
      deposit prior to the date of the proposed payment, such money when
      deposited to be held in trust for the benefit of the Persons entitled to
      such Defaulted Interest as in this Clause (1) provided. Thereupon, the
      Trustee shall fix a Special Record Date for the payment of such Defaulted
      Interest which shall be not more than 15 days and not less than 10 days
      prior to the date of the proposed payment and not less than 10 days after
      the receipt by the Trustee of the notice of the proposed payment. The
      Trustee shall promptly notify the Company of such Special Record Date and,
      in the name and at the expense of the Company, shall cause notice of the
      proposed payment of such Defaulted Interest and the Special Record Date
      therefor to be mailed, first-class postage prepaid, to each Holder at his
      address as it appears in the Security Register, not less than 10 days
      prior to such Special Record Date. Notice of the proposed payment of such
      Defaulted Interest and the Special Record Date therefor having been so
      mailed, such Defaulted Interest shall be paid to the Persons in whose
      names the Securities (or their respective Predecessor Securities) are
      registered at the close of business on such Special Record Date and shall
      no longer be payable pursuant to the following Clause (2).

            (2) The Company may make payment of any Defaulted Interest in any
      other lawful manner not inconsistent with the requirements of any
      securities exchange on which the Securities may be listed, and upon such
      notice as may be required by such exchange, if, after notice given by the
      Company to the Trustee of the proposed payment pursuant to this Clause
      (2), such manner of payment shall be deemed practicable by the Trustee.
      

            Subject to the foregoing provisions of this Section, each Security
delivered under this Indenture upon registration of transfer of or in exchange
for or in lieu of any 


                                       35
   43

other Security shall carry the rights to interest accrued and unpaid, and to
accrue, which were carried by such other Security.

            In the case of any Security which is converted after any Regular
Record Date and on or prior to the corresponding Interest Payment Date, interest
on such Security whose Stated Maturity is on such Interest Payment Date shall be
deemed to continue to accrue and shall be payable on such Interest Payment Date
notwithstanding such conversion and notwithstanding that such Security may have
been called for redemption on a Redemption Date within such period, and such
interest (whether or not punctually paid or duly provided for) shall be paid to
the Person in whose name that Security (or one or more Predecessor Securities)
is registered at the close of business on such Regular Record Date. Except as
otherwise expressly provided in the immediately preceding sentence, in the case
of any Security which is converted, interest whose Stated Maturity is after the
date of conversion of such Security shall not be payable (although such accrued
and unpaid interest will be deemed paid by the appropriate portion of the Common
Stock received by the holders upon such conversion).

            SECTION 3.08. Persons Deemed Owners. Prior to due presentment of a
Security for registration of transfer, the Company, the Trustee and any agent of
the Company or the Trustee may treat the Person in whose name such Security is
registered as the owner of such Security for the purpose of receiving payment of
principal of, premium, if any, and (subject to Section 3.07) interest on such
Security and for all other purposes whatsoever, whether or not such Security be
overdue, and neither the Company, the Trustee nor any agent of the Company or
the Trustee shall be affected by notice to the contrary.

            SECTION 3.09. Cancellation. All Securities surrendered for payment,
redemption, repurchase, registration of transfer or exchange or conversion
shall, if surrendered to any Person other than the Trustee, be delivered to the
Trustee and shall be promptly cancelled by it. The Company may at any time
deliver to the Trustee for cancellation any Securities previously authenticated
and delivered hereunder which the Company may have acquired in any manner
whatsoever, and all Securities so delivered shall be promptly cancelled by the
Trustee. No Securities shall be authenticated in lieu of or in exchange for any
Securities cancelled as provided in this Section, except as expressly permitted
by this Indenture. All cancelled Securities held by the Trustee shall be
disposed of as directed by a Company Order.

            SECTION 3.10. Computation of Interest. Interest on the Securities of
each series shall be computed on the basis of a 360-day year of twelve 30-day
months.

                                   ARTICLE IV

                           Satisfaction and Discharge

            SECTION 4.01. Satisfaction and Discharge of Indenture. This
Indenture shall upon Company request cease to be of further effect (except as to
any surviving rights of conversion, registration of transfer or exchange of
Securities herein 


                                       36
   44

expressly provided for), and the Trustee, at the expense of the Company, shall
execute proper instruments acknowledging satisfaction and discharge of this
Indenture, when

            (1) either

                  (A) all Securities theretofore authenticated and delivered
            (other than (i) Securities which have been destroyed, lost or stolen
            and which have been replaced or paid as provided in Section 3.06 and
            (ii) Securities for whose payment money has theretofore been
            deposited in trust or segregated and held in trust by the Company
            and thereafter repaid to the Company or discharged from such trust,
            as provided in Section 10.03) have been delivered to the Trustee for
            cancellation; or

                  (B) all such Securities not theretofore delivered to the
            Trustee for cancellation

                        (i) have become due and payable, or

                        (ii) will become due and payable at their Stated
                  Maturity within one year, or

                        (iii) are to be called for redemption within one year
                  under arrangements satisfactory to the Trustee for the giving
                  of notice of redemption by the Trustee in the name, and at the
                  expense, of the Company,

                  and the Company, in the case of (i), (ii) or (iii) above, has
                  deposited or caused to be deposited irrevocably with the
                  Trustee as trust funds in trust for the benefit of Holders of
                  Outstanding Securities in an amount sufficient to pay and
                  discharge the entire indebtedness on such Securities not
                  theretofore delivered to the Trustee for cancellation, for
                  principal (and premium, if any) and interest to the date of
                  such deposit (in the case of Securities which have become due
                  and payable) or to the Stated Maturity or Redemption Date, as
                  the case may be;

            (2) the Company has paid or caused to be paid all other sums payable
      hereunder by the Company;

            (3) the Company has delivered to the Trustee an Officers'
      Certificate and an Opinion of Counsel, each stating that all conditions
      precedent herein provided for relating to the satisfaction and discharge
      of this Indenture have been complied with; and 

            (4) no Event of Default which, with notice or lapse of time, or
      both, would become an Event of Default with respect to the Securities
      shall have occurred and be continuing on the date of such deposit.


                                       37
   45

Notwithstanding the satisfaction and discharge of this Indenture, the
obligations of the Company to the Trustee under Section 6.07, the obligations of
the Trustee to any Authenticating Agent under Section 6.14 and, if money shall
have been deposited with the Trustee pursuant to subclause (B) of Clause (1) of
this Section, the obligations of the Trustee under Section 4.02 and the last
paragraph of Section 10.03 shall survive.

            SECTION 4.02. Application of Trust Money. Subject to the provisions
of the last paragraph of Section 10.03, all money deposited with the Trustee
pursuant to Section 4.01 shall be held in trust and applied by it, in accordance
with the provisions of the Securities and this Indenture, to the payment, either
directly or through any Paying Agent (including the Company acting as its own
Paying Agent) as the Trustee may determine, to the Persons entitled thereto, of
the principal (and premium, if any) and interest for whose payment such money
has been deposited with the Trustee. All moneys deposited with the Trustee
pursuant to Section 4.01 (and held by it or any Paying Agent) for the payment of
Securities subsequently converted shall be returned to the Company upon Company
Request.

                                    ARTICLE V

                                    Remedies

            SECTION 5.01. Events of Default. "Event of Default", wherever used
herein, means any one of the following events (whatever the reason for such
Event of Default and whether it shall be occasioned by the provisions of Article
XII or be voluntary or involuntary or be effected by operation of law or
pursuant to any judgment, decree or order of any court or any order, rule or
regulation of any administrative or governmental body):

            (1) default in the payment of any interest (including Additional
      Interest) upon any Security when it becomes due and payable, and
      continuance of such default for a period of 30 days (whether or not such
      payment is prohibited by the provisions of Article XII); or

            (2) default in the payment of the principal of (or premium, if any,
      on) any Security at its Maturity (whether or not such payment is
      prohibited by the provisions of Article XII); or

            (3) failure by the Company to provide the notice of a Change of
      Control in accordance with Section 14.02 or notice of a Change of Control
      or default in the payment of the Repurchase Price in respect of any Note
      on the Repurchase Date therefor (whether or not such payment is prohibited
      by the provisions of Article XII); or

            (4) default in the performance, or breach, of any covenant or
      warranty of the Company in this Indenture (other than a covenant or
      warranty a default in whose performance or whose breach is elsewhere in
      this Section specifically dealt with), and continuance of such default or
      breach for a period of 60 days after there 


                                       38
   46

      has been given, by registered or certified mail, to the Company by the
      Trustee or to the Company and the Trustee by the Holders of at least 25%
      in principal amount of the Outstanding Securities a written notice
      specifying such default or breach and requiring it to be remedied and
      stating that such notice is a "Notice of Default" hereunder; or

            (5) a default under any bonds, debentures, notes or other evidences
      of indebtedness for money borrowed by the Company or a Subsidiary or under
      any mortgages, indentures or instruments under which there may be issued
      or by which there may be secured or evidenced any indebtedness for money
      borrowed by the Company or a Subsidiary, whether such indebtedness now
      exists or shall hereafter be created, other than under a Non-Recourse
      Obligation, which indebtedness, individually or in the aggregate, has a
      principal amount outstanding in excess of U.S.$3,000,000, which default
      shall constitute a failure to pay any portion of the principal of such
      indebtedness when due and payable after the expiration of any applicable
      grace or cure period with respect thereto or shall have resulted in such
      indebtedness becoming or being declared due and payable prior to the date
      on which it would otherwise have become due and payable, without such
      indebtedness having been discharged, or such acceleration having been
      rescinded or annulled, within a period of 10 days after there shall have
      been given, by registered or certified mail, to the Company by the Trustee
      or to the Company and the Trustee by the Holders of at least 25% in
      principal amount of the Outstanding Securities a written notice specifying
      such default and requiring the Company to cause such indebtedness to be
      discharged or cause such acceleration to be rescinded or annulled and
      stating that such notice is a "Notice of Default" hereunder; or

            (6) the entry by a court having jurisdiction in the premises of (A)
      a decree or order for relief in respect of the Company or a Subsidiary in
      an involuntary case or proceeding under any applicable Federal or State
      bankruptcy, insolvency, reorganization or other similar law or (B) a
      decree or order adjudging the Company or a subsidiary bankrupt or
      insolvent, or approving as properly filed a petition seeking
      reorganization, arrangement, adjustment or composition of or in respect of
      the Company or a subsidiary under any applicable Federal or State law, or
      appointing a custodian, receiver, liquidator, assignee, trustee,
      sequestrator or other similar official of the Company or a Subsidiary or
      of any substantial part of their respective properties, or ordering the
      winding up or liquidation of the affairs of the Company or a Subsidiary,
      and the continuance of any such decree or order for relief or any such
      other decree or order unstayed and in effect for a period of 60
      consecutive days; or

            (7) the commencement by the Company or a Subsidiary of a voluntary
      case or proceeding under any applicable Federal or State bankruptcy,
      insolvency, reorganization or other similar law or of any other case or
      proceeding to be adjudicated a bankrupt or insolvent, or the consent by
      either the Company or a Subsidiary to the entry of a decree or order for
      relief in respect of the Company or a Subsidiary in an involuntary case or
      proceeding under any applicable Federal or 


                                       39
   47

      State bankruptcy, insolvency, reorganization or other similar law or to
      the commencement of any bankruptcy or insolvency case or proceeding
      against either the Company or a Subsidiary, or the filing by either the
      Company or a Subsidiary of a petition or answer or consent seeking
      reorganization or relief under any applicable Federal or State law, or the
      consent by either the Company or a Subsidiary to the filing of such
      petition or to the appointment of or taking possession by a custodian,
      receiver, liquidator, assignee, trustee, sequestrator or other similar
      official of the Company or a Subsidiary or of any substantial part of
      their respective properties, or the making by either the Company or a
      Subsidiary of an assignment for the benefit of creditors, or the admission
      by either the Company or a Subsidiary in writing of an inability to pay
      the debts of either the Company or a Subsidiary generally as they become
      due, or the taking of corporate action by the Company or a Subsidiary in
      furtherance of any such action.

            SECTION 5.02. Acceleration of Maturity; Rescission and Annulment. If
an Event of Default (other than an Event of Default specified in Section
5.01(1), 5.01(2), 5.01(6) or 5.01(7)) occurs and is continuing, then in every
such case the Trustee or the Holders of not less than 2S% in principal amount of
the Outstanding Securities may declare the principal of all the Securities to be
due and payable immediately, by a notice in writing to the Company (and to the
Trustee if given by Holders), and upon any such declaration such principal and
any accrued interest (including Additional Interest) thereon shall become
immediately due and payable. If an Event of Default specified in Section 5.01(6)
or 5.01(7) occurs, the principal of, and accrued interest (including Additional
Interest) on, all the Securities shall automatically, and without any
declaration or other action on the part of the Trustee or any Holder, become
immediately due and payable.

            At any time after such a declaration of acceleration has been made
and before a judgment or decree for payment of the money due has been obtained
by the Trustee as hereinafter in this Article V provided, the Holders of a
majority in principal amount of the Outstanding Securities, by written notice to
the Company and the Trustee, may rescind and annul such declaration and its
consequences if

            (1) the Company has paid or deposited with the Trustee a sum
      sufficient to pay

                  (A) all overdue interest (including Additional Interest) on
            all Securities,

                  (B) the principal of (and premium, if any, on) any Securities
            which have become due otherwise than by such declaration of
            acceleration and interest thereon at the rate borne by the
            Securities,

                  (C) to the extent that payment of such interest is lawful,
            interest upon overdue interest at the rate borne by the Securities,
            and


                                       40
   48

                  (D) all sums paid or advanced by the Trustee hereunder and the
            reasonable compensation, expenses, disbursements and advances of the
            Trustee, its agents and counsel;

      and

            (2) all Events of Default, other than the non-payment of the
      principal of Securities which have become due solely by such declaration
      of acceleration, have been cured or waived as provided in Section 5.13.

No such rescission shall affect any subsequent default or impair any right
consequent thereon.

            SECTION 5.03. Collection of Indebtedness and Suits for Enforcement
by Trustee. If

            (1) default is made in the payment of any interest on any Security
      when such interest becomes due and payable and such default continues for
      a period of 30 days, or

            (2) default is made in the payment of the principal of (or premium,
      if any, on) any Security at the Maturity thereof, 

the Trustee is authorized to recover judgment in its own name and as trustee of
an express trust against the Company for the whole amount then due and payable
on such Securities for principal (and premium, if any) and interest, and, to the
extent that payment of such interest shall be legally enforceable, interest on
any overdue principal (and premium, if any) and on any overdue interest, at the
rate borne by the Securities, and, in addition thereto, such further amount as
shall be sufficient to cover the costs and expenses of collection, including the
reasonable compensation, expenses, disbursements and advances of the Trustee,
its agents and counsel.

            If an Event of Default occurs and is continuing, the Trustee may in
its discretion proceed to protect and enforce its rights and the rights of the
Holders by such appropriate judicial proceedings as the Trustee shall deem most
effectual to protect and enforce any such rights, whether for the specific
enforcement of any covenant or agreement in this Indenture or in aid of the
exercise of any power granted herein, or to enforce any other proper remedy.

            SECTION 5.04. Trustee May File Proofs of Claim. In case of any
judicial proceeding relative to the Company (or any otherobligor upon the
Securities), its property or its creditors, the Trustee shall be entitled and
empowered, by intervention in such proceeding or otherwise,

            (1) to file and prove a claim for the whole amount of principal and
      interest owing and unpaid in respect of the Securities and to file such
      other papers or documents as may be necessary or advisable in order to
      have the claims of the Trustee (including any claim for the reasonable
      compensation, expenses, 


                                       41
   49

      disbursements and advances of the Trustee, its agents and counsel) and of
      the Holders allowed in such judicial proceeding, and

            (2) to collect and receive any moneys or other property payable or
      deliverable on any such claim and to distribute the same; 

and any custodian, receiver, assignee, trustee, liquidator, sequestrator or
other similar official in any such judicial proceeding is hereby authorized by
each Holder to make such payments to the Trustee and, in the event that the
Trustee shall consent to the making of such payments directly to the Holders, to
pay to the Trustee any amount due it for the reasonable compensation, expenses,
disbursements and advances of the Trustee, its agents and counsel, and any other
amounts due the Trustee under Section 6.07.

            No provision of this Indenture shall be deemed to authorize the
Trustee to authorize or consent to or accept or adopt on behalf of any Holder
any plan of or organization, arrangement, adjustment or composition affecting
the Securities or the rights of any Holder thereof or to authorize the Trustee
to vote in respect of the claim of any Holder in any such proceeding; provided,
however, that the Trustee may, on behalf of the Holders, vote for the election
of a trustee in bankruptcy or similar official and be a member of a creditors'
or other similar committee.

            SECTION 5.05. Trustee May Enforce Claims Without Possession of
Securities. All rights of action and claims under this Indenture or the
Securities may be prosecuted and enforced by the Trustee without the possession
of any of the Securities or the production thereof in any proceeding relating
thereto, and any such proceeding instituted by the Trustee shall be brought in
its own name as trustee of an express trust, and any recovery of judgment shall,
after provision for the payment of the reasonable compensation, expenses,
disbursements and advances of the Trustee, its agents and counsel, be for the
ratable benefit of the Holders of the Securities in respect of which such
judgment has been recovered.

            SECTION 5.06. Application of Money Collected. Any money collected by
the Trustee pursuant to this Article V shallbe applied in the following order,
at the date or dates fixed by the Trustee and, in case of the distribution of
such money on account of principal (or premium, if any) or interest, upon
presentation of the Securities and the notation thereon of the payment if only
partially paid and upon surrender thereof if fully paid:

            FIRST: to the payment of all amounts due the Trustee under Section
      6.07;

            SECOND: subject to Article XII to the payment of the amounts then
      due and unpaid for first, interest (including Additional Interest) on,
      and, second, for principal of (and premium, if any, on) the Securities in
      respect of which or for the benefit of which such money has been
      collected, ratably, without preference or priority of any kind, according
      to the amounts due and payable on such Securities for interest and
      principal (and premium, if any) respectively; and


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            THIRD: the balance, if any, to the Person or Persons entitled
      thereto, as their interest may appear or as a court of competent
      jurisdiction shall direct.

            SECTION 5.07. Limitation on Suits. No Holder of any Security shall
have any right to institute any, judicial or otherwise, with respect to this
Indenture, or for the appointment of a receiver or trustee, or for any other
remedy hereunder, unless

            (1) such Holder has previously given written notice to the Trustee
      of a continuing Event of Default; 

            (2) the Holders of not less than 25% in principal amount of the
      Outstanding Securities shall have made written request to the Trustee to
      institute proceedings in respect of such Event of Default in its own name
      as Trustee hereunder;

            (3) such Holder or Holders have offered to the Trustee reasonable
      indemnity against the costs, expenses and liabilities to be incurred in
      compliance with such request;

            (4) the Trustee for 60 days after its receipt of such notice,
      request and offer of indemnity has failed to institute any such
      proceeding; and

            (5) no direction inconsistent with such written request has been
      given to the Trustee during such 60-day period by the Holders of a
      majority in principal amount of the Outstanding Securities;

it being understood and intended that no one or more of such Holders shall have
any right in any manner whatever by virtue of, or by availing of, any provision
of this Indenture to affect, disturb or prejudice the fights of any other of
such Holders, or to obtain or to seek to obtain priority or preference over any
other of such Holders or to enforce any right under this Indenture, except in
the manner herein provided and for the equal and ratable benefit of all of such
Holders.

            SECTION 5.08. Unconditional Right of Holders to Receive Principal,
Premium and Interest and to Convert. Notwithstanding any other provision in this
Indenture, the Holder of any Security shall have the right, which is absolute
and unconditional, to receive payment of the principal of (and premium, if any)
and (subject to Section 3.07) interest on such Security on the respective Stated
Maturities expressed in such Security (or, in the case of redemption or
repurchase, on the Redemption Date or Repurchase Date, as the case may be) and
to convert such Security in accordance with Article XIII and to institute suit
for the enforcement of any such payment and right to convert, and such rights
shall not be impaired without the consent of such Holder.

            SECTION 5.09. Restoration of Rights and Remedies. If the Trustee or
any Holder has instituted any proceeding to enforceany right or remedy under
this Indenture and such proceeding has been discontinued or abandoned for any
reason, or has been determined adversely to the Trustee or to such Holder, then
and in every such case, 


                                       43
   51

subject to any determination in such proceeding, the Company, the Trustee and
the Holders shall be restored severally and respectively to their former
positions hereunder and thereafter all rights and remedies of the Trustee and
the Holders shall continue as though no such proceeding had been instituted.

            SECTION 5.10. Rights and Remedies Cumulative. Except as otherwise
provided with respect to the replacement or paymentof mutilated, destroyed, lost
or stolen Securities in the last paragraph of Section 3.06, no right or remedy
herein conferred upon or reserved to the Trustee or to the Holders is intended
to be exclusive of any other right or remedy, and every right and remedy shall,
to the extent permitted by law, be cumulative and in addition to every other
right and remedy given hereunder or now or hereafter existing at law or in
equity or otherwise. The assertion or employment of any right or remedy
hereunder, or otherwise, shall not prevent the concurrent assertion or
employment of any other appropriate right or remedy.

            SECTION 5.11. Delay or Omission Not Waiver. No delay or omission of
the Trustee or of any Holder of any Securitiesto exercise any right or remedy
accruing upon any Event of Default shall impair any such right or remedy or
constitute a waiver of any such Event of Default or an acquiescence therein.
Every right and remedy given by this Article V or by law to the Trustee or to
the Holders may be exercised from time to time, and as often as may be deemed
expedient, by the Trustee or by the Holders, as the case may be.

            SECTION 5.12. Control by Holders. The Holders of a majority in
principal amount of the Outstanding Securitiesshall have the right to direct the
time, method and place of conducting any proceeding for any remedy available to
the Trustee or exercising any trust or power conferred on the Trustee; provided
that

            (1) such direction shall not be in conflict with any rule of law or
      with this Indenture, and

            (2) the Trustee may take any other action deemed proper by the
      Trustee which is not inconsistent with such direction. 

            SECTION 5.13. Waiver of Past Defaults. The Holders of not less than
a majority in principal amount of the Outstanding Securities may on behalf of
the Holders of all the Securities waive any past default hereunder and its
consequences, except a default

            (1) in the payment of the principal of (or premium, if any) or
      interest on any Security, or

            (2) in respect of a covenant or provision hereof which under Article
      IX cannot be modified or amended without the consent of the Holder of each
      Outstanding Security affected. 

            Upon any such waiver, such default shall cease to exist, and any
Event of Default arising therefrom shall be deemed to have been cured, for every
purpose of this 


                                       44
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Indenture; but no such waiver shall extend to any subsequent or other default or
impair any right consequent thereon.

            SECTION 5.14. Undertaking for Costs. In any suit for the enforcement
of any right or remedy under this, or in any suit against the Trustee for any
action taken, suffered or omitted by it as Trustee, a court may require any
party litigant in such suit to file an undertaking to pay the costs of such
suit, and may assess costs against any such party litigant, having due regard to
the merits and good faith of the claims or defenses made by such party litigant;
provided, that this Section 5.14 shall not be deemed to authorize any court to
require such an undertaking or to make such an assessment in any suit instituted
by the Company or in any suit for the enforcement of the right to convert any
Security in accordance with Article XIII.

            SECTION 5.15. Waiver of Usury, Stay or Extension Laws. The Company
covenants (to the extent that it may lawfully do so) that it will not at any
time insist upon, or plead, or in any manner whatsoever claim or take the
benefit or advantage of, any usury, stay or extension law wherever enacted, now
or at any time hereafter in force, which may affect the covenants or the
performance of this Indenture; and the Company (to the extent that it may
lawfully do so) hereby expressly waives all benefit or advantage of any such law
and covenants that it will not hinder, delay or impede the execution of any
power herein granted to the Trustee, but will suffer and permit the execution of
every such power as though no such law had been enacted.

                                   ARTICLE VI

                                   The Trustee

            SECTION 6.01. Certain Duties and Responsibilities. (a) Except during
the continuance of an Event of Default,

            (1) the Trustee undertakes to perform such duties and only such
      duties as are specifically set forth in this Indenture, and no implied
      covenants or obligations shall be read into this Indenture against the
      Trustee; and

            (2) in the absence of bad faith on its part, the Trustee may
      conclusively rely, as to the truth of the statements and the correctness
      of the opinions expressed therein, upon certificates or opinions furnished
      to the Trustee and conforming to the requirements of this Indenture; but
      in the case of any such certificates or opinions which by any provision
      hereof are specifically required to be furnished to the Trustee, the
      Trustee shall be under a duty to examine the same to determine whether or
      not they conform to the requirements of this Indenture.

            (b) In case an Event of Default has occurred and is continuing, the
Trustee shall exercise such of the rights and powers vested in it by this
Indenture, and use the same degree of care and skill in their exercise, as a
prudent person would exercise or use under the circumstances in the conduct of
his or her own affairs.


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            (c) No provision of this Indenture shall be construed to relieve the
Trustee from liability for its own negligent action, its own negligent failure
to act, or its own willful misconduct, except that 

            (1) this paragraph (c) shall not be construed to limit the effect of
paragraph (a) of this Section;

            (2) the Trustee shall not be liable for any error of judgment made
      in good faith by a Responsible Officer, unless it shall be proved that the
      Trustee was negligent in ascertaining the pertinent facts;

            (3) the Trustee shall not be liable with respect to any action taken
      or omitted to be taken by it in good faith in accordance with the
      direction of the Holders of a majority in principal amount of the
      Outstanding Securities relating to the time, method and place of
      conducting any proceeding for any remedy available to the Trustee, or
      exercising any trust or power conferred upon the Trustee, under this
      Indenture; and

            (4) no provision of this Indenture shall require the Trustee to
      expend or risk its own funds or otherwise incur any financial liability in
      the performance of any of its duties hereunder, or in the exercise of any
      of its rights or powers.

            (d) Whether or not therein expressly so provided, every provision of
this Indenture relating to the conduct or affecting the liability of or
affording protection to the Trustee (as Trustee, Paying Agent, Authenticating
Agent or Security Registrar) shall be subject to the provisions of this Section.

            SECTION 6.02. Notice of Defaults. Within 90 days after the
occurrence of any default hereunder, the Trusteeshall give the Holders, in the
manner provided in Section 1.06, notice of any default hereunder actually known
to a Responsible Officer of the Trustee; provided, however, that in the case of
any default of the character specified in Section 5.01(3), no such notice to
Holders shall be given until at least 30 days after the occurrence thereof. The
Trustee shall not be deemed to have notice of a default unless (i) the Trustee
has received written notice thereof from the Company or any Holder or (ii) a
Responsible Officer of the Trustee shall have actual knowledge thereof. For the
purpose of this Section, the term "default" means any event which is, or after
notice or lapse of time or both would become, an Event of Default.

            SECTION 6.03. Certain Rights of Trustee. Subject to the provisions
of Section 6.01:

            (a) the Trustee may rely and shall be protected in acting or
      refraining from acting upon any resolution, certificate, statement,
      instrument, opinion, report, notice, request, direction, consent, order,
      bond, debenture, note, other evidence of indebtedness or other paper or
      document believed by it to be genuine and to have been signed or presented
      by the proper party or parties;


                                       46
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            (b) any request or direction of the Company mentioned herein shall
      be sufficiently evidenced by a Company Request or Company Order and any
      resolution of the Board of Directors shall be sufficiently evidenced by a
      Board Resolution;

            (c) whenever in the administration of this Indenture the Trustee
      shall deem it desirable that a matter be proved or established prior to
      taking, suffering or omitting any action hereunder, the Trustee (unless
      other evidence be herein specifically prescribed) may require and, in the
      absence of bad faith on its part, rely upon an Officers' Certificate;

            (d) the Trustee may consult with counsel and the written advice of
      such counsel or any Opinion of Counsel shall be full and complete
      authorization and protection in respect of any action taken, suffered or
      omitted by it hereunder in good faith and in reliance thereon;

            (e) the Trustee shall be under no obligation to exercise any of the
      rights or powers vested in it by this Indenture at the request or
      direction of any of the Holders pursuant to this Indenture, unless such
      Holders shall have offered to the Trustee reasonable security or indemnity
      against the costs, expenses and liabilities which might be incurred by it
      in compliance with such request or direction;

            (f) the Trustee shall not be bound to make any investigation into
      the facts or matters stated in any resolution, certificate, statement,
      instrument, opinion, report, notice, request, direction, consent, order,
      bond, debenture, note, other evidence of indebtedness or other paper or
      document, but the Trustee, in its discretion, may make such further
      inquiry or investigation into such facts or matters as it may see fit,
      and, if the Trustee shall determine to make such further inquiry or
      investigation, it shall be entitled to examine the books, records and
      premises of the Company, personally or by agent or attorney; and

            (g) the Trustee may execute any of the trusts or powers hereunder or
      perform any duties hereunder either directly or by or through agents or
      attorneys and the Trustee shall not be responsible for any misconduct or
      negligence on the part of any agent or attorney appointed with due care by
      it hereunder.

            SECTION 6.04. Not Responsible for Recitals or Issuance of
Securities. The recitals contained herein and in the Securities, except the
Trustee's certificates of authentication, shall be taken as the statements of
the Company, and neither the Trustee nor any Authenticating Agent assumes any
responsibility for their correctness. The Trustee makes no representations as to
the validity or sufficiency of this Indenture or of the Securities. Neither the
Trustee nor any Authenticating Agent shall be accountable for the use or
application by the Company of Securities or the proceeds thereof.


                                       47
   55

            SECTION 6.05. May Hold Securities. The Trustee, any Authenticating
Agent, any Paying Agent, any Security Registrar or any other agent of the
Company, in its individual or any other capacity, may become the owner or
pledgee of Securities and, subject to Section 6.08 and Section 6.13, may
otherwise deal with the Company with the same rights it would have if it were
not Trustee, Authenticating Agent, Paying Agent, Security Registrar or such
other agent.

            SECTION 6.06. Money Held in Trust. Money held by the Trustee in
trust hereunder need not be segregatedfrom other funds except to the extent
required by law. The Trustee shall be under no liability for interest on any
money received by it hereunder except as otherwise agreed with the Company.

            SECTION 6.07. Compensation and Reimbursement. The Company agrees:

            (1) to pay to the Trustee from time to time reasonable compensation
for all services rendered by it hereunder (which compensation shall not be
limited by any provision of law in regard to the compensation of a trustee of an
express trust);

            (2) except as otherwise expressly provided herein, to reimburse the
Trustee upon its request for all reasonable expenses, disbursements and advances
incurred or made by the Trustee in accordance with any provision of this
Indenture (including the reasonable compensation and the expenses and
disbursements of its agents and counsel), except any such expense, disbursement
or advance as may be attributable to its negligence or bad faith; and

            (3) to indemnify the Trustee for, and to hold it harmless against,
any loss, liability or expense incurred without negligence, willful misconduct
or bad faith on its part, arising out of or in connection with the acceptance or
administration of this trust, including the costs and expenses of defending
itself against any claim or liability in connection with the exercise or
performance of any of its powers or duties hereunder. The Trustee shall notify
the Company of any claim asserted against it for which it may seek indemnity.

            (4) All indemnifications and releases from liability granted
hereunder to the Trustee shall extend to its officers, directors, employees,
agents, successors and assigns.

            (5) When the Trustee incurs expenses or renders services after the
occurrence of any Event of Default specified in Section 5.01, the expenses and
the compensation for the services are intended to constitute expenses of
administration under any bankruptcy, insolvency or similar laws.

            (6) The obligations of the Company under this Section shall survive
the satisfaction and discharge of this Indenture. 


                                       48
   56

            SECTION 6.08. Disqualification: Conflicting Interests. If the
Trustee has or shall acquire a conflicting interest within the meaning of the
Trust Indenture Act, the Trustee shall either eliminate such interest or resign,
to the extent and in the manner provided by, and subject to the provisions of,
the Trust Indenture Act and this Indenture.

            SECTION 6.09. Corporate Trustee Required; Eligibility. There shall
at all times be a Trustee hereunder which shall be a corporationorganized and
doing business under the laws of the United States, authorized under such laws
to exercise corporate trust powers, which shall have (or, in the case of a
corporation included in a bank holding company system, the related bank holding
company shall have) a combined capital and surplus of at least U.S.$50,000,000,
subject to supervision or examination by federal or state authority, in good
standing and having an established place of business or agency in the Borough of
Manhattan, The City of New York or, Richmond, Virginia. If such corporation or
related bank holding company publishes reports of condition at least annually,
pursuant to law or to the requirements of said supervising or examining
authority, then for the purposes of this Section, the combined capital and
surplus of such corporation or related bank holding company shall be deemed to
be its combined capital and surplus as set forth in its most recent report of
condition so published. If at any time the Trustee shall cease to be eligible in
accordance with the provisions of this Section, it shall resign immediately in
the manner and with the effect hereinafter specified in this Article.

            SECTION 6.10. Resignation and Removal; Appointment of Successor. (a)
No resignation or removal of the Trustee and no appointment of asuccessor
Trustee pursuant to this Article shall become effective until the acceptance of
appointment by the successor Trustee in accordance with the applicable
requirements of Section 6.11.

            (b) The Trustee may resign at any time by giving written notice
thereof to the Company. If the instrument of acceptance by a successor Trustee
required by Section 6.11 shall not have been delivered to the Trustee within 30
days after the giving of such notice of resignation, the resigning Trustee may
petition any court of competent jurisdiction for the appointment of a successor
Trustee.

            (c) The Trustee may be removed at any time by Act of the Holders of
a majority in principal amount of the Outstanding Securities, delivered to the
Trustee and to the Company. 

            (d) If at any time:

            (1) the Trustee shall fail to comply with Section 6.08 after written
      request therefor by the Company or by any Holder who has been a bona fide
      Holder of a Security for at least six months, or


                                       49
   57

            (2) the Trustee shall cease to be eligible under Section 6.09 and
      shall fail to resign after written request therefor by the Company or by
      any such Holder, or

            (3) the Trustee shall become incapable of acting or shall be
      adjudged a bankrupt or insolvent or a receiver of the Trustee or of its
      property shall be appointed or any public officer shall take charge or
      control of the Trustee or of its property or affairs for the purpose of
      rehabilitation, conservation or liquidation,

then, in any such case, (i) the Company by a Board Resolution may remove the
Trustee, or (ii) subject to Section 5.14, any Holder who has been a bona fide
Holder of a Security for at least six months may, on behalf of himself and all
others similarly situated, petition any court of competent jurisdiction for the
removal of the Trustee and the appointment of a successor Trustee.

            (e) If the Trustee shall resign, be removed or become incapable of
acting, or if a vacancy shall occur in the office of Trustee for any cause, the
Company, by a Board Resolution, shall promptly appoint a successor Trustee. If,
within one year after such resignation, removal or incapability, or the
occurrence of such vacancy, a successor Trustee shall be appointed by Act of the
Holders of a majority in principal amount of the Outstanding Securities
delivered to the Company and the retiring Trustee, the successor Trustee so
appointed shall, forthwith upon its acceptance of such appointment in accordance
with the applicable requirements of Section 6.11, become the successor Trustee
and to that extent supersede the successor Trustee appointed by the Company. If
no successor Trustee shall have been so appointed by the Company or the Holders
and accepted appointment in the manner required by Section 6.11, any Holder who
has been a bona fide Holder of a Security for at least six months may, on behalf
of himself and all others similarly situated, petition any court of competent
jurisdiction for the appointment of a successor Trustee.

            (f) The Company shall give notice of each resignation and each
removal of the Trustee and each appointment of a successor Trustee to all
Holders in the manner provided in Section 1.06. Each notice shall include the
name of the successor Trustee and the address of its Corporate Trust Office.

            SECTION 6.11. Acceptance of Appointment by Successor. Every
successor Trustee appointed hereunder shall execute, acknowledgeand deliver to
the Company and to the retiring Trustee an instrument accepting such
appointment, and thereupon the resignation or removal of the retiring Trustee
shall become effective and such successor Trustee, without any further act, deed
or conveyance, shall become vested with all the rights, powers, trusts and
duties of the retiring Trustee; but, on the request of the Company or the
successor Trustee, such retiring Trustee shall, upon payment of its charges,
execute and deliver an instrument transferring to such successor Trustee all the
rights, powers and trusts of the retiring Trustee and shall duly assign,
transfer and deliver to such successor Trustee all property and money held by
such retiring Trustee hereunder. Upon request of any such successor Trustee, the
Company shall execute any and all 


                                       50
   58

instruments for more fully and certainly vesting in and confirming to such
successor Trustee all such rights, powers and trusts.

            No successor Trustee shall accept its appointment unless at the time
of such acceptance such successor Trustee shall be qualified and eligible under
this Article.

            SECTION 6.12. Merger, Conversion, Consolidation or Succession to
Business. Any corporation into which the Trustee may be merged or converted or
with which it may be consolidated, or any corporation resulting from any merger,
conversion or consolidation to which the Trustee shall be a party, or any
corporation succeeding to all or substantially all the corporate trust business
of the Trustee, shall be the successor of the Trustee hereunder, provided such
corporation shall be otherwise qualified and eligible under this Article.
Without the execution or filing of any paper or any further act on the part of
any of the parties hereto. In case any Securities shall have been authenticated,
but not delivered, by the Trustee then in office, any successor by merger,
conversion or consolidation to such authenticating Trustee may adopt such
authentication and deliver the Securities so authenticated with the same effect
as if such successor Trustee had itself authenticated such Securities.

            SECTION 6.13. Preferential Collection of Claims Against Company. If
and when the Trustee shall be or become a creditor of the Company (or any other
obligor upon the Securities), the Trustee shall be subject to the provisions of
the Trust Indenture Act regarding the collection of claims against the Company
(or any such other obligor).

            SECTION 6.14. Appointment of Authenticating Agent. The Trustee may
appoint an Authenticating Agent or Agents which shall be authorized to act on
behalf of the Trustee to authenticate Securities issued upon original issue and
upon exchange, registration of transfer, partial conversion, partial redemption,
or partial repurchase or pursuant to Section 3.06, and Securities so
authenticated shall be entitled to the benefits of this Indenture and shall be
valid and obligatory for all purposes as if authenticated by the Trustee
hereunder. Wherever reference is made in this Indenture to the authentication
and delivery of Securities by the Trustee or the Trustee's certificate of
authentication, such reference shall be deemed to include authentication and
delivery on behalf of the Trustee by an Authenticating Agent and a certificate
of authentication executed on behalf of the Trustee by an Authenticating Agent.
Each Authenticating Agent shall be acceptable to the Company and shall at all
times be a corporation organized and doing business under the laws of the United
States, authorized under such laws to act as Authenticating Agent, which shall
have (or, in the case of a corporation included in a bank holding company
system, the related bank holding company shall have) a combined capital and
surplus of not less than U.S.$50,000,000 and subject to supervision or
examination by Federal or State authority. If such Authenticating Agent
publishes reports of condition at least annually, pursuant to law or to the
requirements of said supervising or examining authority, then, for the purposes
of this Section, the combined capital and surplus of such Authenticating Agent
or related bank holding company shall be deemed to be its combined capital and
surplus as set forth in its most recent report of condition so published. If at
any time an Authenticating Agent shall 


                                       51
   59

cease to be eligible in accordance with the provisions of this Section, such
Authenticating Agent shall resign immediately in the manner and with the effect
specified in this Section.

            Any corporation into which an Authenticating Agent may be merged or
converted or with which it may be consolidated, or any corporation resulting
from any merger, conversion or consolidation to which such Authenticating Agent
shall be a party, or any corporation succeeding to the corporate agency or
corporate trust business of an Authenticating Agent, shall continue to be an
Authenticating Agent, provided such corporation shall be otherwise eligible
under this Section, without the execution or filing of any paper or any further
act on the part of the Trustee or the Authenticating Agent.

            An Authenticating Agent may resign at any time by giving written
notice thereof to the Trustee and to the Company. The Trustee may at any time
terminate the agency of an Authenticating Agent by giving written notice thereof
to such Authenticating Agent and to the Company. Upon receiving such a notice of
resignation or upon such a termination, or in case at any time such
Authenticating Agent shall cease to be eligible in accordance with the
provisions of this Section, the Trustee may appoint a successor Authenticating
Agent which shall be acceptable to the Company and shall mail written notice of
such appointment by first-class mail, postage prepaid, to all Holders as their
names and addresses appear in the Security Register. Any successor
Authenticating Agent upon acceptance of its appointment hereunder shall become
vested with all the rights, powers and duties of its predecessor hereunder, with
like effect as if originally named as an Authenticating Agent. No successor
Authenticating Agent shall be appointed unless eligible under the provisions of
this Section.

            The Trustee agrees to pay to each Authenticating Agent from time to
time reasonable compensation for its services under this Section, and the
Trustee shall be entitled to be reimbursed for such payments, subject to the
provisions of Section 6.07.

            If an appointment is made pursuant to this Section, the Securities
may have endorsed thereon, in addition to the Trustee's certificate of
authentication, an alternative certificate of authentication in the following
form:

            This is one of the Securities described in the within-mentioned
Indenture.


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                                    ----------------------------------------
                                           As Trustee


                                    By
                                       -------------------------------------
                                           As Authenticating Agent


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

            SECTION 6.15. Appointment of Co-Trustee. Subject to the
qualifications set forth in Section 6.09, the Trustee may appoint an additional
institution as a separate trustee or co-trustee. If the Trustee appoints an
additional institution as a separate trustee or co-trustee, each and every
remedy, power, fight, claim, deed, cause of action, immunity, estate, duty,
obligation, title, interest and lien expressed or intended by this Indenture to
be exercised by, vested in and conveyed by the Trustee with respect thereto
shall be exercisable by, vested in and conveyed to such separate trustee or
co-trustee, but only to the extent necessary to enable such separate trustee or
co-trustee to exercise such powers, rights and remedies, and every covenant and
obligation necessary for the exercise thereby by such separate trustee or
co-trustee shall run to and be enforceable by either of them. Should any
instrument in writing from the Company be required by the separate trustee or
co-trustee so appointed by the Trustee for more fully vesting in and confirming
to them such properties, rights, powers, trusts, duties and obligations, any and
all such instruments in writing shall, on request, be executed, acknowledged and
delivered by the Company. If any separate trustee or co-trustee, or a successor
to either, shall become incapable of acting or not qualified to act, resign or
be removed, all the estate, properties, rights, powers, trusts, duties and
obligations of such separate trustee or co-trustee, so far as permitted by law,
shall vest in and be exercised by the Trustee until the appointment of a
successor to such separate trustee or co-trustee. The appointment of any
separate trustee or co-trustee shall be subject to written approval of the
Company so long as no Event of Default has occurred and is continuing under this
Indenture.

                                  ARTICLE VII

                Holders' Lists and Reports by Trustee and Company

            SECTION 7.01. Company to Furnish Trustee Names and Addresses of
Holders. The Company will furnish or cause to be furnished to the Trustee

            (a) semi-annually, not more than 15 days after each Regular Report
Date, a list, in such form as the Trustee may reasonably require, of the names
and addresses of the Holders as of such Regular Record Date, and


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            (b) at such other times as the Trustee may request in writing,
within 30 days after the receipt by the Company of any such request, a list of
similar form and content as of a date not more than 15 days prior to the time
such list is furnished; 

excluding from any such list names and addresses received by the Trustee in its
capacity as Security Registrar.

            SECTION 7.02. Preservation of Information; Communications to
Holders. (a) The Trustee shall preserve, in as current a form as is reasonably
practicable, the names and addresses of Holders contained in the most recent
list furnished to the Trustee as provided in Section 7.01 and the names and
addresses of Holders received by the Trustee in its capacity as Security
Registrar. The Trustee may destroy any list furnished to it as provided in
Section 7.01 upon receipt of a new list so furnished.

            (b) The rights of Holders to communicate with other Holders with
respect to their rights under this Indenture or under the Securities, and the
corresponding rights and duties of the Trustee, shall be as provided by the
Trust Indenture Act.

            (c) Every Holder of Securities, by receiving and holding the same,
agrees with the Company and the Trustee that neither the Company nor the Trustee
nor any agent of either of them shall be held accountable by reason of any
disclosure of information as to names and addresses of Holders made pursuant to
the Trust Indenture Act. 

            SECTION 7.03. Reports by Trustee. (a) The Trustee shall transmit to
Holders such reports concerning the Trustee and its actions under this Indenture
as may be required pursuant to the Trust Indenture Act at the times and in the
manner provided pursuant thereto.

            (b) A copy of each such report shall, at the time of such
transmission to Holders, be filed by the Trustee with each stock exchange upon
which the Securities are listed, with the Commission, if applicable, and with
the Company. The Company will notify the Trustee when the Securities are listed
on any stock exchange.

            SECTION 7.04. Reports by Company. (a) The Company shall file with
the Trustee and the Commission, if applicable, and transmit to Holders, such
information, documents and other reports, and such summaries thereof, as may be
required pursuant to the Trust Indenture Act at the times and in the manner
provided pursuant to such Act; provided that any such information, documents or
reports required to be filed with the Commission pursuant to Section 13 or 15(d)
of the Exchange Act shall be filed with the Trustee within 15 days after the
same is so required to be filed with the Commission. Notwithstanding anything to
the contrary contained herein, the Trustee shall have no duty to review such
documents for the purpose of determining compliance with this Indenture.

            (b) The Company shall provide the Trustee with at least 30 days'
prior notice of any change in location of its principal executive offices or
other principal place of business.


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                                  ARTICLE VIII

              Consolidation, Merger, Conveyance, Transfer or Lease

            SECTION 8.01. Company May Consolidate, Etc., Only on Certain Terms.
The Company shall not consolidate with or merge into any other Person or,
directly or indirectly, convey, transfer, sell, lease or otherwise dispose of
all or substantially all of its properties and assets to any Person, and the
Company shall not permit any Person to consolidate with or merge into the
Company or convey, transfer, sell, lease or otherwise dispose of all or
substantially all of its properties and assets to the Company, unless:

            (1) in case the Company shall consolidate with or merge into another
      Person or convey, transfer or lease its properties and assets
      substantially as an entirety to any Person, the Person formed by such
      consolidation or into which the Company is merged or the Person which
      acquires by conveyance or transfer, or which leases, the properties and
      assets of the Company substantially as an entirety shall be a corporation,
      partnership or trust, shall be organized and validly existing under the
      laws of the United States of America, any State thereof or the District of
      Columbia and shall expressly assume, by an indenture supplemental hereto,
      executed and delivered to the Trustee, in form satisfactory to the
      Trustee, the due and punctual payment of the principal of (and premium, if
      any) and interest (including Additional Interest) on all the Securities
      and the performance or observance of every covenant of this Indenture on
      the part of the Company to be performed or observed and shall have
      provided for conversion rights in accordance with Article XIII;

            (2) immediately after giving effect to such transaction, no Event of
      Default, and no event which, after notice or lapse of time or both, would
      become an Event of Default, shall have happened and be continuing; and 

            (3) the Company has delivered to the Trustee an Officers'
      Certificate and an Opinion of Counsel, each stating that such
      consolidation, merger, conveyance, transfer or lease and, if a
      supplemental indenture is required in connection with such transaction,
      such supplemental indenture comply with this Article and that all
      conditions precedent herein provided for relating to such transaction have
      been complied with.

            SECTION 8.02. Successor Substituted. Upon any consolidation of the
Company with, or merger of the Company into, any other Person or any conveyance,
transfer or lease of the properties and assets of the Company substantially as
an entirety in accordance with Section 8.01, the successor Person formed by such
consolidation or into which the Company is merged or to which such conveyance,
transfer or lease is made shall succeed to, and be substituted for, and may
exercise every right and power of, the Company under this Indenture with the
same effect as if such successor Person had been named as the Company herein,
and thereafter, except in the case of a lease, the 


                                       55
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predecessor Person shall be released from its obligations and covenants under
this Indenture and the Securities.

                                   ARTICLE IX

                             Supplemental Indentures

            SECTION 9.01. Supplemental Indentures Without Consent of Holders.
Without the consent of any Holders, the Company, when authorized by a Board
Resolution, and the Trustee, at any time and from time to time, may enter into
one or more indentures supplemental hereto, in form satisfactory to the Trustee,
for any of the following purposes:

            (1) to evidence the succession of another Person to the Company and
      the assumption by any such successor of the covenants of the Company
      herein and in the Securities; or

            (2) to add to the covenants of the Company for the equal and ratable
      benefit of the Holders, or to surrender any right or power herein
      conferred upon the Company; or

            (3) to secure the Company's obligations in respect of the
      Securities; or

            (4) to make provision with respect to the conversion rights of
      Holders pursuant to the requirements of Article XIII; or

            (5) to make any changes or modifications to this Indenture necessary
      in connection with the registration of any Transfer Restricted Securities
      under the Securities Act as contemplated by Section 10.11, provided that
      such action pursuant to this clause (5) shall not adversely affect the
      interests of the Holders of Securities; or

            (6) to cure any ambiguity, to correct or supplement any provision
      herein which may be inconsistent with any other provision herein, to
      correct or supplement any provision herein which limits, qualifies or
      conflicts with a provision of the Trust Indenture Act which is required
      under such Act to be a part of and govern this Indenture, in any case to
      the extent necessary to qualify this Indenture under the Trust Indenture
      Act, or to make any other provisions with respect to matters or questions
      arising under this Indenture which shall not be inconsistent with the
      provisions of this Indenture; provided that such action pursuant to this
      clause (6) shall not adversely affect the interests or legal rights of the
      Holders in any material respect.

            SECTION 9.02. Supplemental Indentures With Consent of Holders. With
the consent of the Holders of not less than a majority in principal amount of
the Outstanding Securities, by the Act of said Holders delivered to the Company
and the Trustee, the Company, when authorized by a Board Resolution, and the
Trustee may enter into an indenture or indentures supplemental hereto for the
purpose of adding any 


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provisions to or changing in any manner or eliminating any of the provisions of
this Indenture or of modifying in any manner the rights of the Holders under
this Indenture; provided, however, that no such supplemental indenture shall,
without the consent of the Holder of each Outstanding Security affected thereby,

            (1) change the Stated Maturity of the principal of, or any
      installment of interest on, any Security, or reduce the principal amount
      thereof or the rate of interest thereon or any premium payable upon the
      redemption thereof, or change the place of payment where, or the coin or
      currency in which, any Security or any premium or interest thereon is
      payable, or impair the right to institute suit for the enforcement of any
      such payment on or after the Stated Maturity thereof (or, in the case of
      redemption or repurchase, on or after the Redemption Date or Repurchase
      Date, as the case may be), or adversely affect the right to convert any
      Security as provided in Article XIII (except as permitted by Section
      9.01(4)), or modify the provisions of this Indenture with respect to the
      subordination of the Securities in a manner adverse to the Holders, or
      modify the redemption provisions in a manner adverse to the Holders, or
      modify the provisions relating to the Company's requirement to offer to
      repurchase Notes upon a Change in Control in a manner adverse to the
      Holders, or

            (2) modify any of the provisions of this Section 9.02, Section 5.13
      or Section 10.08, except to increase any such percentage or to provide
      that certain other provisions of this Indenture cannot be modified or
      waived without the consent of the Holder of each Outstanding Security
      affected thereby, or

            (3) modify the obligation of the Company to maintain an office or
      agency in the Borough of Manhattan, The City of New York or Richmond,
      Virginia pursuant to Section 10.02, or

            (4) modify any of the provisions of Section 10.09 or Section 10.10,
      or

            (5) reduce the percentage in principal amount of the Outstanding
      Securities, the consent of whose Holders is required for any such
      supplemental indenture, or the consent of whose Holders is required for
      any waiver (of compliance with certain provisions of this Indenture or
      certain defaults hereunder and their consequences) provided for in this
      Indenture. 

            It shall not be necessary for any Act of Holders under this Section
to approve the particular form of any proposed supplemental indenture, but it
shall be sufficient if such Act shall approve the substance thereof.

            SECTION 9.03. Execution of Supplemental Indentures. In executing, or
accepting the additional trusts created by, any supplemental indenture permitted
by this Article IX or the modifications thereby of the trusts created by this
Indenture, the Trustee shall be entitled to receive, and (subject to Section
6.01 and Section 6.03) shall be fully protected in relying upon, an Opinion of
Counsel stating that the execution of such supplemental indenture is authorized
or permitted by this Indenture, 


                                       57
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complies with its terms and will, upon the execution and delivery thereof, be
valid and binding upon the Company in accordance with its terms. The Trustee
may, but shall not be obligated to, enter into any such supplemental indenture
which affects the Trustee's own rights, duties or immunities under this
Indenture or otherwise.

            SECTION 9.04. Effect of Supplemental Indentures. Upon the execution
of any supplemental indenture under this Article, this Indenture shall be
modified in accordance therewith, and such supplemental indenture shall form a
part of this Indenture for all purposes; and every Holder of Securities
theretofore or thereafter authenticated and delivered hereunder shall be bound
thereby.

            SECTION 9.05. Conformity with Trust Indenture Act. Every
supplemental indenture executed pursuant to this Article shall conform to the
requirements of the Trust Indenture Act.

            SECTION 9.06. Reference in Securities to Supplemental Indentures.
Securities authenticated and delivered after the execution of any supplemental
indenture pursuant to this Article may, and shall if required by the Trustee,
bear a notation in form approved by the Trustee as to any matter provided for in
such supplemental indenture. If the Company shall so determine, new Securities
so modified as to conform, in the judgment of the Trustee and the Company, to
any such supplemental indenture may be prepared and executed by the Company and
authenticated and delivered by the Trustee in exchange for Outstanding
Securities.

                                   ARTICLE X

                                    Covenants

            SECTION 10.01. Payment of Principal, Premium and Interest. The
Company will duly and punctually pay the principal of (and premium, if any) and
interest on the Securities in accordance with the terms of the Securities and
this Indenture.

            SECTION 10.02. Maintenance of Office or Agency. The Company will
maintain in the Borough of Manhattan, The City of New York or Richmond, Virginia
an office or agency where Securities may be presented or surrendered for
payment, where Securities may be surrendered for registration of transfer or
exchange, where Securities may be surrendered for conversion and where notices
and demands to or upon the Company in respect of the Securities and this
Indenture may be served. The Company will give prompt written notice to the
Trustee of the location, and any change in the location, of such office or
agency. If at any time the Company shall fail to maintain any such required
office or agency or shall fail to furnish the Trustee with the address thereof,
such presentations, surrenders, notices and demands may be made or served at the
Corporate Trust Office of the Trustee or the office or agency of the Trustee in
the Borough of Manhattan, The City of New York, and the Company hereby appoints
the Trustee as its agent to receive all such presentations, surrenders, notices
and demands.


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            The Company may also from time to time designate one or more other
offices or agencies (in or outside the Borough of Manhattan, The City of New
York or Richmond, Virginia) where the Securities may be presented or surrendered
for any or all such purposes and may from time to time rescind such
designations; provided, however, that no such designation or rescission shall in
any manner relieve the Company of its obligation to maintain offices or agencies
in the Borough of Manhattan, The City of New York or Richmond, Virginia for such
purposes. The Company will give prompt written notice to the Trustee of any such
designation or rescission and of any change in the location of any such other
office or agency.

            SECTION 10.03. Money for Security Payments to Be Held in Trust. If
the Company shall at any time act as its own Paying Agent, it will, on or before
each due date of the principal of (and premium, if any) or interest (together
with any Additional Interest in respect thereof) on any of the Securities,
segregate and hold in trust for the benefit of the Persons entitled thereto a
sum sufficient to pay the principal (and premium, if any) or interest (together
with any Additional Interest in respect thereof) so becoming due until such sums
shall be paid to such Persons or otherwise disposed of as herein provided and
will promptly notify the Trustee of its action or failure so to act.

            Whenever the Company shall have one or more Paying Agents, it will,
prior to each due date of the principal of (and premium, if any) or interest
(together with any Additional Interest in respect thereof) on any Securities,
deposit with a Paying Agent a sum sufficient to pay such amount, such sum to be
held in trust for the benefit of the Persons entitled to such principal,
premium, if any, or interest, and (unless such Paying Agent is the Trustee) the
Company will promptly notify the Trustee of its action or failure so to act.

            The Company will cause each Paying Agent other than the Trustee to
execute and deliver to the Trustee an instrument in which such Paying Agent
shall agree with the Trustee, subject to the provisions of this Section 10.03,
that such Paying Agent will:

            (1) hold all sums held by it for the payment of the principal of,
      premium, if any, or interest on Securities in trust for the benefit of the
      Persons entitled thereto until such sums shall be paid to such Persons or
      otherwise disposed of as herein provided;

            (2) give the Trustee notice of any default by the Company (or any
      other obligor upon the Securities) in the making of any payment of
      principal, premium, if any, or interest; and

            (3) at any time during the continuance of any such default, upon the
      written request of the Trustee, forthwith pay to the Trustee all sums so
      held in trust by such Paying Agent.

            The Company may at any time, for the purpose of obtaining the
satisfaction and discharge of this Indenture or for any other purpose, pay, or
by Company


                                       59
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Order direct any Paying Agent to pay, to the Trustee all sums held in trust by
the Company or such Paying Agent, such sums to be held by the Trustee upon the
same trusts as those upon which such sums were held by the Company or such
Paying Agent; and, upon such payment by any Paying Agent to the Trustee, such
Paying Agent shall be released from all further liability with respect to such
money.

            Any money deposited with the Trustee or any Paying Agent, or then
held by the Company, in trust for the payment of the principal of (and premium,
if any) or interest (together with any Additional Interest in respect thereof)
on any Security and remaining unclaimed for two years after such principal (and
premium, if any) or interest has become due and payable shall be paid to the
Company on Company Request, or (if then held by the Company) shall be discharged
from such trust; and the Holder of such Security shall thereafter, as an
unsecured. general creditor, look only to the Company for payment thereof, and
all liability of the Trustee or such Paying Agent with respect to such trust
money, and all liability of the Company as trustee thereof, shall thereupon
cease; provided, however, that the Trustee or such Paying Agent, before being
required to make any such repayment, may at the expense of the Company cause to
be published once, in a newspaper published in the English language, customarily
published on each Business Day and of general circulation in the Borough of
Manhattan, The City of New York, notice that such money remains unclaimed and
that, after a date specified therein, which shall not be less than 30 days from
the date of such publication, any unclaimed balance of such money then remaining
will be repaid to the Company.

            SECTION 10.04. Statement by Officers as to Default. The Company will
deliver to the Trustee, within 120 days after the end of each fiscal year of the
Company ending after the date hereof, an Officers' Certificate, stating whether
or not to the best knowledge of the signers thereof the Company is in default in
the performance and observance of any of the terms, provisions and conditions of
this Indenture (without regard to any period of grace or requirement of notice
provided hereunder) and, if the Company shall be in default, specifying all such
defaults and the nature and status thereof of which they may have knowledge.

            SECTION 10.05. Existence. Subject to Article VIII, the Company will
do or cause to be done all things necessary to preserve and keep in full force
and effect its existence, rights (charter and statutory) and franchises;
provided, however, that the Company shall not be required to preserve any such
right or franchise if the Board of Directors shall determine that the
preservation thereof is no longer desirable in the conduct of the business of
the Company and that the loss thereof is not disadvantageous in any material
respect to the Holders.

            SECTION 10.06. Maintenance of Properties. The Company will cause all
properties used or useful in the conduct of its business or the business of any
Subsidiary to be maintained and kept in good condition, repair and working order
and supplied with all necessary equipment and will cause to be made all
necessary repairs, renewals, replacements, betterments and improvements thereof,
all as in the judgment of the Company may be necessary so that the business
carried on in connection therewith may be properly and advantageously conducted
at all times; provided, however, that 


                                       60
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nothing in this Section shall prevent the Company from discontinuing the
operation or maintenance of any of such properties, or disposing of any of them,
if such discontinuance or disposition is, in the judgment of the Company,
desirable in the conduct of its business or the business of any Subsidiary and
not disadvantageous in any material respect to the Holders.

            SECTION 10.07. Payment of Taxes and Other Claims. The Company will
pay or discharge or cause to be paid or discharged, before the same shall become
delinquent, (1) all taxes, assessments and governmental charges levied or
imposed upon the Company or any Subsidiary or upon the income, profits or
property of the Company or any Subsidiary, and (2) all lawful claims for labor,
materials and supplies which, if unpaid, might by law become a lien upon the
property of the Company or any Subsidiary; provided, however, that the Company
shall not be required to pay or discharge or cause to be paid or discharged any
such tax, assessment, charge or claim whose amount, applicability or validity is
being contested in good faith by appropriate proceedings.

            SECTION 10.08. Waiver of Certain Covenants. The Company may omit in
any particular instance to comply with any covenant or condition set forth in
Sections 10.05 to 10.07, inclusive, if before the time for such compliance the
Holders of at least a majority in principal amount of the Outstanding Securities
shall, by Act of such Holders, either waive such compliance in such instance or
generally waive compliance with such covenant or condition, but no such waiver
shall extend to or affect such covenant or condition except to the extent so
expressly waived, and, until such waiver shall become effective, the obligations
of the Company and the duties of the Trustee in respect of any such covenant or
condition shall remain in full force and effect.

            SECTION 10.09. Delivery of Certain Information. At any time when the
Company is not subject to Section 13 or l5(d) of the Exchange Act, upon the
request of a Holder or the holder of shares of Common Stock issued upon
conversion thereof, the Company will promptly furnish or cause to be furnished
Rule 144A Information (as defined below) to such Holder or such holder of shares
of Common Stock issued upon conversion of Securities, or to a prospective
purchaser of any such security designated by any such Holder or holder, as the
case may be, to the extent required to permit compliance by such Holder or
holder with Rule 144A under the Securities Act in connection with the resale of
any such security. "Rule 144A Information" shall be such information as is
specified pursuant to Rule 144A(d)(4) under the Securities Act.

            SECTION 10.10. Resale of Certain Securities; Reporting Issuer.
During the period beginning on the last date of original issuance of the
Securities and ending on the date that is two years from such date, the Company
will not, and will use its best efforts not to permit any of its "affiliates"
(as defined under Rule 144 under the Securities Act or any successor provision
thereto) to, resell (x) any Securities which constitute "restricted securities"
under Rule 144 or (y) any securities into which the Securities have been
converted under this Indenture which constitute "restricted securities" under
Rule 144, that in either case have been reacquired by any of them. The Trustee
shall have no responsibility in respect of the Company's performance of its
agreement in the preceding sentence.


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            SECTION 10.11. Registration Rights. The Company agrees that the
Holders (and any Person that has a beneficial interest in a Security) from time
to time of Transfer Restricted Securities are entitled to the benefits of a
Registration Rights Agreement, dated as of October 15, 1997 (the "Registration
Rights Agreement"), executed by the Company. Pursuant to the Registration Rights
Agreement, the Company has agreed for the benefit of the Holders from time to
time of Transfer Restricted Securities, at the Company's expense, (i) to file
within 90 days after the first date of original issuance of the Securities, a
shelf registration statement (the "Shelf Registration Statement") with the
Commission with respect to resales of the Transfer Restricted Securities, (ii)
to use its best efforts to cause such Shelf Registration Statement to be
declared effective by the Commission as soon as practicable, and (iii) to use
its best efforts to maintain such Shelf Registration Statement continuously
effective under the Securities Act for a period of two years from the last date
of original issuance of the Securities or, if earlier, (A) until there are no
outstanding Transfer Restricted Securities or (B) until all outstanding Transfer
Restricted Securities held by persons that are not affiliates of the Company may
be resold without registration under the Securities Act pursuant to Rule 144(k)
under the Securities Act or any successor provision thereof.

            Additional interest (the "Additional Interest") with respect to the
Securities shall be assessed as follows if any of the following events occur
(each such event in clauses (i) through (iii) below being herein called a
"Registration Default"):

            (i) if on or prior to the 90th day after the first date of original
      issuance of the Securities the Shelf Registration Statement has not been
      filed with the Commission;

            (ii) if on or prior to the 120th day after the first date of
      original issuance of the Securities the Shelf Registration Statement has
      not been declared effective by the Commission; or 

            (iii) if after the Shelf Registration Statement is declared
      effective (A) the Shelf Registration Statement thereafter ceases to be
      effective; or (B) the Shelf Registration Statement or the related
      prospectus ceases to be usable (in each case except as permitted in
      paragraph (b) below) in connection with resales of Transfer Restricted
      Securities in accordance with and during the periods specified herein
      because either (1) any event occurs as a result of which the related
      prospectus forming part of such Shelf Registration Statement would include
      any untrue statement of a material fact or omit to state any material fact
      necessary to make the statements therein in the light of the circumstances
      under which they were made not misleading, or (2) it shall be necessary to
      amend such Shelf Registration Statement or supplement the related
      prospectus, to comply with the Securities Act or the Exchange Act or the
      respective rules thereunder. 

            Additional Interest shall accrue on the Securities over and above
the interest set forth in the title of the Securities from and including the
date on which any such Registration Default shall occur, to but excluding the
date on which all such Registration Defaults have been cured, at a rate of 0.50%
per annum.


                                       62
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            (b) A Registration Default shall be deemed not to have occurred and
be continuing in relation to the Shelf Registration Statement or the related
prospectus if (i) such Registration Default has occurred solely as a result of
(x) the filing of a post-effective amendment to the Shelf Registration Statement
to incorporate annual audited financial information with respect to the Company
where such post-effective amendment is not yet effective and needs to be
declared effective to permit Holders to use the related prospectus or (y) other
material events with respect to the Company that would need to be described in
the Shelf Registration Statement or the related prospectus and (ii) in the case
of clause (y), the Company proceeds promptly and in good faith to amend or
supplement the Shelf Registration Statement and related prospectus to describe
such events; provided, however, that in any case if such Registration Default
occurs for a continuous period in excess of 30 days, Additional Interest shall
be payable in accordance with the above paragraph from the day such Registration
Default occurs until such Registration Default is cured.

            (c) Any amounts of Additional Interest due pursuant to clause
(a)(i), (a)(ii) or (a)(iii) of this Section 10.11 will be payable in cash on the
regular Interest Payment Dates. The amount of Additional Interest will be
determined by multiplying the applicable Additional Interest rate by the
principal amount of the Securities, multiplied by a fraction, the numerator of
which is the number of days such Additional Interest rate was applicable during
such period (determined on the basis of a 360-day year comprised of twelve
30-day months), and the denominator of which is 360.

            Whenever in this Indenture there is mentioned, in any context, the
payment of the principal of, premium, if any, or interest on, or in respect of,
any Security, such mention shall be deemed to include mention of the payment of
Additional Interest provided for in this Section to the extent that, in such
context, Additional Interest are, were or would be payable in respect thereof
pursuant to the provisions of this Section and express mention of the payment of
Additional Interest (if applicable) in any provisions hereof shall not be
construed as excluding Additional Interest in those provisions hereof where such
express mention is not made.

                                   ARTICLE XI

                            Redemption of Securities

            SECTION 11.01. Right of Redemption. The Securities may be redeemed
at the election of the Company, as a whole or from time to time in part, at any
time on or after October 20, 2000, at the Redemption Prices specified in the
form of Security hereinbefore set forth, together with accrued interest to the
Redemption Date.

            SECTION 11.02. Applicability of Article. Redemption of Securities at
the election of the Company or otherwise, as permitted or required by any
provision of this Indenture, shall be made in accordance with such provision and
this Article XI.

            SECTION 11.03. Election to Redeem; Notice to Trustee. The election
of the Company to redeem any Securities pursuant to Section 11.01 shall be


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evidenced by a Board Resolution. In case of any redemption at the election of
the Company, the Company shall, at least 40 days prior to the Redemption Date
fixed by the Company (unless a shorter notice shall be satisfactory to the
Trustee), notify the Trustee of such Redemption Date and of the principal amount
of Securities to be redeemed.

            SECTION 11.04. Selection by Trustee of Securities to Be Redeemed. If
less than all the Securities are to be redeemed, the particular Securities to be
redeemed shall be selected not less than 20 days or more than 40 days prior to
the Redemption Date by the Trustee, from the Outstanding Securities not
previously called for redemption, by such method as the Trustee shall deem fair
and appropriate in the circumstances and which may provide for the selection for
redemption of portions (equal to U.S.$1,000 or any integral multiple thereof) of
the principal amount of Securities of a denomination larger than U.S.$1,000.

            If any Security selected for partial redemption is converted in part
before termination of the conversion right with respect to the portion of the
Security so selected, the converted portion of such Security shall be deemed (so
far as may be) to be the portion selected for redemption. Securities which have
been converted during a selection of Securities to be redeemed shall be treated
by the Trustee as Outstanding for the purpose of such selection.

            The Trustee shall promptly notify the Company and each Security
Registrar in writing of the Securities selected for redemption and, in the case
of any Securities selected for partial redemption, the principal amount thereof
to be redeemed.

            For all purposes of this Indenture, unless the context otherwise
requires, all provisions relating to the redemption of Securities shall relate,
in the case of any Securities redeemed or to be redeemed only in part, to the
portion of the principal amount of such Securities which has been or is to be
redeemed.

            SECTION 11.05. Notice of Redemption. Notice of redemption shall be
given by first-class mail, postage prepaid, mailed not less than 20 nor more
than 40 days prior to the Redemption Date, to each Holder of Securities to be
redeemed, at his address appearing in the Security Register.

            All notices of redemption shall state:

            (1) the Redemption Date,

            (2) the Redemption Price,

            (3) if less than all the Outstanding Securities are to be redeemed,
      the identification (and, in the case of partial redemption of any
      Securities, the principal amounts) of the particular Securities to be
      redeemed,

            (4) that on the Redemption Date the Redemption Price will become due
      and payable upon each such Security to be redeemed and that interest
      thereon will cease to accrue on and after said date,


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            (5) the conversion price, the date on which the right to convert the
      Securities to be redeemed will terminate and the place or places where
      such Securities may be surrendered for conversion, and

            (6) the place or places where such Securities are to be surrendered
      for payment of the Redemption Price. Notice of redemption of Securities to
      be redeemed at the election of the Company shall be given by the Company
      or, at the Company's request, by the Trustee in the name and at the
      expense of the Company, and shall be irrevocable.

            SECTION 11.06. Deposit of Redemption Price. On or prior to any
Redemption Date, the Company shall deposit with the Trustee or with a Paying
Agent (or, if the Company is acting as its own Paying Agent, segregate and hold
in trust as provided in Section 10.03) an amount of money sufficient to pay the
Redemption Price of, and (except if the Redemption Date shall be an Interest
Payment Date) accrued interest on, all the Securities which are to be redeemed
on that date other than any Securities called for redemption on that date which
have been converted prior to the date of such deposit.

            If any Security called for redemption is converted, any money
deposited with the Trustee or with any Paying Agent or so segregated and held in
trust for the redemption of such Security shall (subject to any right of the
Holder of such Security or any Predecessor Security to receive interest as
provided in the last paragraph of Section 3.07) be paid to the Company upon
Company Request or, if then held by the Company, shall be released from such
trust.

            SECTION 11.07. Securities Payable on Redemption Date. Notice of
redemption having been given as aforesaid, the Securities so to be redeemed
shall, on the Redemption Date, become due and payable at the Redemption Price
therein specified, and from and after such date (unless the Company shall
default in the payment of the Redemption Price and accrued interest) such
Securities shall cease to bear or accrue any interest. Upon surrender of any
such Security for redemption in accordance with said notice, such Security shall
be paid by the Company at the Redemption Price, together with accrued interest
to (but not including) the Redemption Date; provided, however, that installments
of interest whose Stated Maturity is on or prior to the Redemption Date shall be
payable to the Holders of such Securities, or one or more Predecessor
Securities, registered as such at the close of business on the relevant Record
Dates according to their terms and the provisions of Section 3.07.

            If any Security called for redemption shall not be so paid upon
surrender thereof for redemption, the principal (and premium, if any) shall,
until paid, bear and accrue interest from the Redemption Date at the rate borne
by the Security.

            SECTION 11.08. Securities Redeemed in Part. Any Security which is to
be redeemed only in part shall be surrendered at an office or agency of the
Company designated for that purpose pursuant to Section 10.02 (with, if the
Company or the 


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Trustee so requires, due endorsement by, or a written instrument of transfer in
form satisfactory to the Company and the Trustee duly executed by, the Holder
thereof or his attorney-in-fact duly authorized in writing), and the Company
shall execute, and the Trustee shall authenticate and deliver to the Holder of
such Security without service charge, a new Security or Securities, of any
authorized denomination as requested by such Holder, in aggregate principal
amount equal to and in exchange for the unredeemed portion of the principal
amount of the Security so surrendered.

            SECTION 11.09. Conversion Arrangement on Call for Redemption. In
connection with any redemption of Securities, the Company may arrange for the
purchase and conversion of any Securities by an agreement with one or more
investment bankers or other purchasers to purchase such Securities by paying to
the Trustee in trust for the Holders, on or before the Redemption Date, an
amount not less than the applicable Redemption Price, together with interest
accrued to the Redemption Date, of such Securities. Notwithstanding anything to
the contrary contained in this Article XI, the obligation of the Company to pay
the Redemption Price of such Securities, together with interest accrued to, but
excluding, the date fixed for redemption, shall be deemed to be satisfied and
discharged to the extent such amount is so paid by such purchasers. If such an
agreement is entered into, a copy of which will be filed with the Trustee prior
to the Redemption Date, any Securities not duly surrendered for conversion by
the holders thereof may, at the option of the Company, be deemed, to the fullest
extent permitted by law, acquired by such purchasers from such holders and
(notwithstanding anything to the contrary contained in Article XIII) surrendered
by such purchasers for conversion, all as of immediately prior to the close of
business on the Redemption Date (and the right to convert any such Securities
shall be deemed to have been extended through such time), subject to payment of
the above amount as aforesaid. At the direction of the Company, the Trustee
shall hold and dispose of any such amount paid to it in the same manner as it
would monies deposited with it by the Company for the redemption of Securities.
Without the Trustee's prior written consent, no arrangement between the Company
and such purchasers for the purchase and conversion of any Securities shall
increase or otherwise affect any of the powers, duties, responsibilities or
obligations of the Trustee as set forth in this Indenture, and the Company
agrees to indemnify the Trustee from, and hold it harmless against, any loss,
liability or expense arising out of or in connection with any such arrangement
for the purchase and conversion of any Securities between the Company and such
purchasers to which the Trustee has not consented in writing, including the
costs and expenses incurred by the Trustee in the defense of any claim or
liability arising out of or in connection with the exercise or performance of
any of its powers, duties, responsibilities or obligations under this Indenture.
Nothing in the preceding sentence shall be deemed to limit the rights and
protections afforded to the Trustee in Article VI hereof, including, but not
limited to, the right to indemnification pursuant to Section 6.07.


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                                  ARTICLE XII

                           Subordination of Securities

            SECTION 12.01. Securities Subordinate to Senior Indebtedness. The
Company covenants and agrees, and each Holder of a Security, by his acceptance
thereof, likewise covenants and agrees, that, to the extent and in the manner
hereinafter set forth in this Article XII, the indebtedness represented by the
Securities and the payment of the principal of (and premium, if any) and
interest on each and all of the Securities and all obligations of the Company
under this Indenture are hereby expressly made subordinate and subject in right
of payment to the prior payment in full of all Senior Indebtedness.

            SECTION 12.02. Payment over of Proceeds upon Dissolution, Etc. In
the event of (a) any insolvency or bankruptcy case or proceeding, or any
receivership, liquidation, reorganization or other similar case or proceeding in
connection therewith, relative to the Company or to its creditors, as such, or
to its assets, or (b) any liquidation, dissolution or other winding up of the
Company, whether voluntary or involuntary and whether or not involving
insolvency or bankruptcy, or (c) any assignment for the benefit of creditors or
any other marshalling of assets and liabilities of the Company, then and in any
such event the holders of Senior Indebtedness shall be entitled to receive
payment in full of all amounts due or to become due on or in respect of all
Senior Indebtedness, or provision shall be made for such payment in cash or cash
equivalents or otherwise in a manner satisfactory to the holders of Senior
Indebtedness, before the Holders of the Securities are entitled to receive any
payment on account of principal of (or premium, if any) or interest on the
Securities, and to that end the holders of Senior Indebtedness shall be entitled
to receive, for application to the payment thereof, any payment or distribution
of any kind or character, whether in cash, property or securities, which may be
payable or deliverable in respect of the Securities in any such case,
proceeding, dissolution, liquidation or other winding up or event.

            In the event that, notwithstanding the foregoing provisions of this
Section, the Trustee or the Holder of any Security shall have received any
payment or distribution of assets of the Company prohibited by the foregoing
paragraph of any kind or character, whether in cash, property or securities,
before all Senior Indebtedness is paid in full or payment thereof provided for,
and if such fact shall, at or prior to the time of such payment or distribution,
have been made actually known to a Responsible Officer of the Trustee or, as the
case may be, such Holder, then and in such event such payment or distribution
shall be paid over or delivered forthwith to the trustee in bankruptcy,
receiver, liquidating trustee, custodian, assignee, agent or other Person making
payment or distribution of assets of the Company for application to the payment
of all Senior Indebtedness remaining unpaid, to the extent necessary to pay all
Senior Indebtedness in full, after giving effect to any concurrent payment or
distribution to or for the holders of Senior Indebtedness.

            For purposes of this Article XII only, the words "cash, property or
securities" shall not be deemed to include shares of capital stock of the
Company as reorganized or readjusted, or securities of the Company or say other
corporation provided 


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for by a plan of reorganization or readjustment which in either case are
subordinated in right of payment to all Senior Indebtedness which may at the
time be outstanding to substantially the same extent as, or to a greater extent
than, the Securities are so subordinated as provided in this Article XII. The
consolidation of the Company with, or the merger of the Company into, another
Person or the liquidation or dissolution of the Company following the conveyance
or transfer of its properties and assets substantially as an entirety to another
Person upon the terms and conditions set forth in Article VIII shall not be
deemed a dissolution, winding up, liquidation, reorganization, assignment for
the benefit of creditors or marshalling of assets and liabilities of the Company
for the purposes of this Section 12.02 if the Person formed by such
consolidation or into which the Company is merged or which acquires by
conveyance or transfer such properties and assets substantially as an entirety,
as the case may be, shall, as a part of such consolidation, merger, conveyance
or transfer, comply with the conditions set forth in Article VIII.

            SECTION 12.03. No Payment When Senior Indebtedness in Default. (a)
In the event and during the continuation of any default in the payment of
principal of (or premium, if any) or interest on any Senior Indebtedness beyond
any applicable grace period with respect thereto (unless and until such payment
default shall have been cured or waived in writing by the holders of such Senior
Indebtedness), or (b) in the event any judicial proceeding shall be pending with
respect to any such default, then no payment shall be made by the Company on
account of principal of (or premium, if any) or interest on the Securities or on
account of the purchase or other acquisition of Securities (including pursuant
to Articles XI and XIII).

            In the event that, notwithstanding the foregoing, the Company shall
make any payment to the Trustee or the Holder of any Security prohibited by the
foregoing provisions of this Section 12.03, and if such fact shall, at or prior
to the time of such payment, have been made actually known to a Responsible
Officer of the Trustee or, as the case may be, such Holder, then and in such
event such payment shall be paid over and delivered forthwith to the Company.

            The provisions of this Section 12.03 shall not apply to any payment
with respect to which Section 12.02 would be applicable.

            SECTION 12.04. Payment Permitted If No Default. Nothing contained in
this Article XII or elsewhere in this Indenture or in any of the Securities
shall prevent (a) the Company, at any time except during the pendency of any
case, proceeding, dissolution, liquidation or other winding up, assignment for
the benefit of creditors or other marshalling of assets and liabilities of the
Company referred to in Section 12.02 or under the conditions described in
Section 12.03, from making payments at any time of principal of (and premium, if
any) or interest on the Securities, or (b) the application by the Trustee of any
money deposited with it hereunder to the payment of or on account of the
principal of (and premium, if any) or interest on the Securities or the
retention of such payment by the Holders, if, at the time of such application by
the Trustee, a Responsible Officer of the Trustee did not have actual knowledge
that such payment would have been prohibited by the provisions of this Article
XII.


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            SECTION 12.05. Subrogation to Rights of Holders of Senior
Indebtedness. Subject to the payment in full of all Senior Indebtedness, and
until the Securities are paid in full, the Holders of the Securities shall be
subrogated (equally and ratably with the holders of all indebtedness of the
Company which by its express terms is subordinated to indebtedness of the
Company to substantially the same extent as the Securities are subordinated and
is entitled to like rights of subrogation) to the rights of the holders of such
Senior Indebtedness to receive payments and distributions of cash, property and
securities applicable to the Senior Indebtedness to the extent that payments and
distributions otherwise payable to Holders of Securities have been applied to
the payment of Senior Indebtedness as provided by this Article XII. For purposes
of such subrogation, no payments or distributions to the holders of the Senior
Indebtedness of any cash, property or securities to which the Holders of the
Securities or the Trustee would be entitled, except for the provisions of this
Article XII, and no payments over pursuant to the provisions of this Article XII
to the holders of Senior Indebtedness by Holders of the Securities or the
Trustee, shall, as among the Company, its creditors other than holders of Senior
Indebtedness and the Holders of the Securities, be deemed to be a payment or
distribution by the Company to or on account of the Senior Indebtedness.

            SECTION 12.06. Provisions Solely to Define Relative Rights. The
provisions of this Article XII are and are intended solely for the purpose of
defining the relative rights of the Holders of the Securities on the one hand
and the holders of Senior Indebtedness on the other hand. Nothing contained in
this Article XII or elsewhere in this Indenture or in the Securities is intended
to or shall (a) impair, as among the Company, its creditors other than holders
of Senior Indebtedness and the Holders of the Securities, the obligation of the
Company, which is absolute and unconditional (and which, subject to the rights
under this Article XII of the holders of Senior Indebtedness, is intended to
rank equally with all other general obligations of the Company), to pay to the
Holders of the Securities the principal of (and premium, if any) and interest on
the Securities as and when the same shall become due and payable in accordance
with their terms; or (b) affect the relative rights against the Company of the
Holders of the Securities and creditors of the Company other than the holders of
Senior Indebtedness; or (c) prevent the Trustee or the Holder of any Security
from exercising all remedies otherwise permitted by applicable law upon default
under this Indenture, subject to the rights, if any, under this Article XII of
the holders of Senior Indebtedness to receive cash, property and securities
otherwise payable or deliverable to the Trustee or such Holder.

            SECTION 12.07. Trustee to Effectuate Subordination. Each holder of a
Security by his acceptance thereof authorizes and directs the Trustee on his
behalf to take such action as may be necessary or appropriate to effectuate the
subordination provided in this Article XII and appoints the Trustee his
attorney-in-fact for any and all such purposes.

            SECTION 12.08. No Waiver of Subordination Provisions. No right of
any present or future holder of any Senior Indebtedness to enforce subordination
as herein provided shall at any time in any way be prejudiced or impaired by any
act or failure to act on the part of the Company or by any act or failure to
act, in good faith, by any such holder, or by any non-compliance by the Company
with the terms, provisions


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and covenants of this Indenture, regardless of any knowledge thereof any such
holder may have or be otherwise charged with.

            Without in any way limiting the generality of the foregoing
paragraph, the holders of Senior Indebtedness may, at any time and from time to
time, without the consent of or notice to the Trustee or the Holders of the
Securities, without incurring responsibility to the Holders of the Securities
and without impairing or releasing the subordination provided in this Article
XII or the obligations hereunder of the Holders of the Securities to the holders
of Senior Indebtedness, do any one or more of the following: (i) change the
manner, place or terms of payment or extend the time of payment of, or renew or
alter, Senior Indebtedness, or otherwise amend or supplement in any manner
Senior Indebtedness or any instrument evidencing the same or any agreement under
which Senior Indebtedness is outstanding; (ii) sell, exchange, release or
otherwise deal with any property pledged, mortgaged or otherwise securing Senior
Indebtedness; (iii) release any Person liable in any manner for the collection
of Senior Indebtedness; (iv) exercise or refrain from exercising any rights
against the Company and any other Person; (v) apply any and all sums received
from time to time to the Senior Indebtedness.

            SECTION 12.09. Notice to Trustee. The Company shall give prompt
written notice to the Trustee of any fact known to the Company which would
prohibit the making of any payment to or by the Trustee in respect of the
Securities. Notwithstanding the provisions of this Article XII or any other
provision of this Indenture, the Trustee shall not be charged with knowledge of
the existence of any facts which would prohibit the making of any payment to or
by the Trustee in respect of the Securities, unless and until the Trustee shall
have received written notice thereof from the Company or a holder of Senior
Indebtedness or from any trustee therefor; and, prior to the receipt of any such
written notice, the Trustee, subject to the provisions of Section 6.01, shall be
entitled in all respects to assume that no such facts exist; provided, however,
that if the Trustee shall not have received the notice provided for in this
Section 12.09 at least two Business Days prior to the date upon which by the
terms hereof any money may become payable for any purpose (including, without
limitation, the payment of the principal of (and premium, if any) or interest on
any Security), then, anything herein contained to the contrary notwithstanding,
the Trustee shall have full power and authority to receive such money and to
apply the same to the purpose for which such money was received and shall not be
affected by any notice to the contrary which may be received by it within two
Business Days prior to such date.

            Subject to the provisions of Section 6.01, the Trustee shall be
entitled to rely on the delivery to it of a written notice by a Person
representing himself to be a holder of Senior Indebtedness (or a trustee
therefor) to establish that such notice has been given by a holder of Senior
Indebtedness (or a trustee therefor). In the event that the Trustee determines
in good faith that further evidence is required with respect to the right of any
Person as a holder of Senior Indebtedness to participate in any payment or
distribution pursuant to this Article XII, the Trustee may request such Person
to furnish evidence to the reasonable satisfaction of the Trustee as to the
amount of Senior Indebtedness held by such Person, the extent to which such
Person is entitled to participate in such payment or distribution and any other
facts pertinent to the rights of 


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such Person under this Article XII, and if such evidence is not furnished, the
Trustee may defer any payment to such Person pending judicial determination as
to the right of such Person to receive such payment.

            SECTION 12.10. Reliance on Judicial Order or Certificate of
Liquidating Agent. Upon any payment or distribution of assets of the Company
referred to in this Article XII, the Trustee, subject to the provisions of
Section 6.01, and the Holders of the Securities shall be entitled to rely upon
any order or decree entered by any court of competent jurisdiction in which such
insolvency, bankruptcy, receivership, liquidation, reorganization, dissolution,
winding up or similar case or proceeding is pending, or a certificate of the
trustee in bankruptcy, receiver, liquidating trustee, custodian, assignee for
the benefit of creditors, agent or other Person making such payment or
distribution, delivered to the Trustee or to the Holders of Securities, for the
purpose of ascertaining the Persons entitled to participate in such payment or
distribution, the holders of the Senior Indebtedness and other indebtedness of
the Company, the amount thereof or payable thereon, the amount or amounts paid
or distributed thereon and all other facts pertinent thereto or to this Article
XII.

            SECTION 12.11. Trustee Not Fiduciary for Holders of Senior
Indebtedness. The Trustee shall not be deemed to owe any fiduciary duty to the
holders of Senior Indebtedness and shall not be liable to any such holders if it
shall in good faith mistakenly pay over or distribute to Holders of Securities
or to the Company or to any other Person cash, property or securities to which
any holders of Senior Indebtedness shall be entitled by virtue of this Article
XII or otherwise.

            SECTION 12.12. Rights of Trustee as Holder of Senior Indebtedness;
Preservation of Trustee's Rights. The Trustee in its individual capacity shall
be entitled to all the rights set forth in this Article XII with respect to any
Senior Indebtedness which may at any time be held by it, to the same extent as
any other holder of Senior Indebtedness, and nothing in this Indenture shall
deprive the Trustee of any of its rights as such holder.

            Nothing in this Article XII shall apply to claims of, or payments
to, the Trustee under or pursuant to Section 6.07.

            SECTION 12.13. Article Applicable to Paying Agents. In case at any
time any Paying Agent other than the Trustee shall have been appointed by the
Company and be then acting hereunder, the term "Trustee" as used in this Article
XII shall in such case (unless the context otherwise requires) be construed as
extending to and including such Paying Agent within its meaning as fully for all
intents and purposes as if such Paying Agent were named in this Article XII in
addition to or in place of the Trustee; provided, however, that Section 12.12
shall not apply to the Company or any Affiliate of the Company if it or such
Affiliate acts as Paying Agent.

            SECTION 12.14. Certain Conversions Deemed Payment. For the purposes
of this Article XII only, (1) the issuance and delivery of junior securities
upon conversion of Securities in accordance with Article XIII shall not be
deemed to constitute


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a payment or distribution on account of the principal of or premium or interest
on Securities or on account of the purchase or other acquisition of Securities,
and (2) the payment, issuance or delivery of cash, property or securities (other
than junior securities) upon conversion of a Security shall be deemed to
constitute payment on account of the principal of such Security. For the
purposes of this Section 12.14, the term "junior securities" means (a) shares of
any stock of any class of the Company and (b) securities of the Company which
are subordinated in right of payment to the prior payment in full of all Senior
Indebtedness which may be outstanding at the time of issuance or delivery of
such securities to substantially the same extent as, or to a greater extent
than, the Securities are so subordinated as provided in this Article XII.
Nothing contained in this Article XII or elsewhere in this Indenture or in the
Securities is intended to or shall impair, as among the Company, its creditors
other than holders of Senior Indebtedness and the Holders of the Securities, the
right, which is absolute and unconditional, of the Holder of any Security to
convert such Security in accordance with Article XIII.

                                  ARTICLE XIII

                            Conversion of Securities

            SECTION 13.01. Conversion Privilege and Conversion Price. Subject to
and upon compliance with the provisions of this Article XIII, at the option of
the Holder thereof, any Security or any portion of the principal amount thereof
which is U.S.$1,000 or an integral multiple of U.S.$1,000 may be converted at
the principal amount thereof, or of such portion thereof, into fully paid and
nonassessable shares of Common Stock of the Company at any time following the
latest date of original issuance of Securities at the conversion price,
determined as hereinafter provided, in effect at the time of conversion. Such
conversion right shall expire at the close of business on the Business Day
immediately preceding October 15, 2007, subject, in the case of conversion of
any Global Security, to any Applicable Procedures. In case a Security or portion
thereof is called for redemption at the election of the Company or the Holder
thereof exercised his right to require the Company to repurchase the Security,
such conversion right in respect of the Security or portion so called shall
expire at the close of business, New York or Virginia time, on the Business Day
immediately preceding the corresponding Redemption Date or Repurchase Date, as
the case may be, unless the Company defaults in making the payment due upon
redemption or repurchase, as the case may be (in each case subject as aforesaid
to any Applicable Procedures with respect to any Global Security).

            The price at which shares of Common Stock shall be delivered upon
conversion (herein called the "conversion price") shall be initially U.S.$13.625
per share of Common Stock. The conversion price shall be adjusted in certain
instances as provided in Section 13.04.

            In case the Company shall, by dividend or otherwise, declare or make
a distribution on its Common Stock referred to in paragraph (4) or (5) of
Section 13.04 (including, without limitation, dividends or distributions
referred to in the last sentence of paragraph (4) of Section 13.04), the Holder
of each Security, upon the conversion thereof 


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pursuant to this Article XIII subsequent to the close of business on the date
fixed for the determination of shareholders entitled to receive such
distribution and prior to the effectiveness of the conversion price adjustment
in respect of such distribution pursuant to paragraph (4) or (5) of Section
13.04, shall also be entitled to receive for each share of Common Stock into
which such Security is converted, the portion of the evidences of indebtedness,
shares of capital stock, securities, cash and other property so distributed
applicable to one share of Common Stock, provided, however, that, at the
election of the Company (whose election shall be evidenced by a Board
Resolution) with respect to all Holders so converting, the Company may, in lieu
of distributing to such Holder any portion of such distribution not consisting
of cash or securities of the Company, pay such Holder an amount in cash equal to
the fair market value thereof (as determined in good faith by the Board of
Directors, whose determination shall be conclusive and described in a Board
Resolution). If any conversion of a Security described in the immediately
preceding sentence occurs prior to the payment date for a distribution to
holders of Common Stock which the Holder of the Security so converted is
entitled to receive in accordance with the immediately preceding sentence, the
Company may elect (such election to be evidenced by a Board Resolution) to
distribute to such Holder a due bill for the evidences of indebtedness, shares
of capital stock, securities, cash or assets to which such Holder is so
entitled, provided that such due bill (i) meets any applicable requirements of
the principal national securities exchange or other market on which the Common
Stock is then traded and (ii) requires payment or delivery of such evidences of
indebtedness, shares of capital stock, securities, cash or assets no later than
the date of payment or delivery thereof to holders of Common Stock receiving
such distribution.

            SECTION 13.02. Exercise of Conversion Privilege. In order to
exercise the conversion privilege, the Holder of any Security to be converted
shall surrender such Security, duly endorsed or assigned to the Company or in
blank, at any office or agency maintained by the Company pursuant to Section
10.02, accompanied by (a) written notice (as set forth in Section 2.05 herein)
to the Company at such office or agency that the Holder elects to convert such
Security or, if less than the entire principal amount thereof is to be
converted, the portion thereof to be converted and (b) if shares or any portion
of such Security not to be converted are to be issued in the name of a Person
other than the Holder thereof, and the restrictions on transfer of such Security
set forth in the first paragraph of Section 2.02 remain in effect, a
certification of the Holder as to compliance with such restrictions (as set
forth in Section 2.06).

            If the restrictions on transfer of a Security set forth in the first
paragraph of Section 2.02 remain in effect, all shares of Common Stock delivered
upon conversion thereof shall bear a restrictive legend substantially in the
form of such paragraph.

            Except as described in the last paragraph of Section 3.07, no Holder
of Securities will be entitled upon conversion thereof to any payment or
adjustment on account of accrued and unpaid interest thereon (although such
accrued and unpaid interest will be deemed paid by the appropriate portion of
the Common Stock received by the holders upon such conversion) or on account of
dividends on the shares of Common Stock issued in connection therewith.
Securities surrendered for conversion during the period from the close of
business on any Regular Record Date to the opening of business 


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on the corresponding Interest Payment Date (except Securities called for
redemption on a Redemption Date within such period between and including such
Regular Record Date and such Interest Payment Date) must be accompanied by
payment to the Company in New York Clearing House Funds or other funds
acceptable to the Company of an amount equal to the interest payable on such
Interest Payment Date on the principal amount converted.

            Securities shall be deemed to have been converted immediately prior
to the close of business on the day of surrender of such Securities for
conversion in accordance with the foregoing provisions, and at such time the
rights of the Holders of such Securities as Holders shall cease, and the Person
or Persons entitled to receive the Common Stock issuable upon conversion shall
be treated for all purposes as the record holder or holders of such Common Stock
at such time. As promptly as practicable on or after the conversion date, the
Company shall issue and shall deliver at such office or agency a certificate or
certificates for the number of full shares of Common Stock issuable upon
conversion, together with payment in lieu of any fraction of a share as provided
in Section 13.03.

            In the case of any Security which is converted in part only, upon
such conversion the Company shall execute and the Trustee shall authenticate and
deliver to the Holder thereof, at the expense of the Company, a new Security or
Securities of authorized denominations in aggregate principal amount equal to
the unconverted portion of the principal amount of such Security. Any
requirements for notice, surrender or delivery of Securities pursuant to this
Article XIII shall, with respect to any Global Security, be subject to any
Applicable Procedures.

            SECTION 13.03. Fractions of Shares. No fractional shares of Common
Stock shall be issued upon conversion of Securities. If more than one Security
shall be surrendered for conversion at one time by the same Holder, the number
of full shares which shall be issuable upon conversion thereof shall be computed
on the basis of the aggregate principal amount of the Securities (or specified
portions thereof) so surrendered. Instead of any fractional share of Common
Stock which would otherwise be issuable upon conversion of any Security or
Securities (or specified portions thereof), the Company shall pay a cash
adjustment in respect of such fraction in an amount equal to the same fraction
of the Closing Price per share of the Common Stock at the close of business on
the day of conversion (or, if such day is not a Trading Day, on the Trading Day
immediately preceding such day) or, alternatively, the Company shall round up to
the next higher whole share.

            SECTION 13.04. Adjustment of Conversion Price. (1) In case the
Company shall pay or make a dividend or other distribution on its Common Stock
exclusively in Common Stock or shall pay or make a dividend or other
distribution on any other class of capital stock of the Company which dividend
or distribution includes Common Stock, the conversion price in effect at the
opening of business on the day next following the date fixed for the
determination of shareholders entitled to receive such dividend or other
distribution shall be reduced by multiplying such conversion price by a fraction
of which the numerator shall be the number of shares of Common Stock 


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outstanding at the close of business on the date fixed for such determination
and the denominator shall be the sum of such number of shares and the total
number of shares constituting such dividend or other distribution, such
reduction to become effective immediately after the opening of business on the
day next following the date fixed for such determination. For the purposes of
this paragraph (1), the number of shares of Common Stock at any time outstanding
shall not include shares held in the treasury of the Company but shall include
shares issuable in respect of scrip certificates issued in lieu of fractions of
shares of Common Stock. The Company shall not pay any dividend or make any
distribution on shares of Common Stock held in the treasury of the Company.

            (2) In case the Company shall pay or make a dividend or other
distribution on its Common Stock consisting exclusively of, or shall otherwise
issue to all holders of its Common Stock, rights, warrants or options entitling
the holders thereof to subscribe for or purchase shares of Common Stock at a
price per share less than the current market price per share (determined as
provided in paragraph (7) of this Section 13.04) of the Common Stock on the date
fixed for the determination of shareholders entitled to receive such rights,
warrants or options, the conversion price in effect at the opening of business
on the day following the date fixed for such determination shall be reduced by
multiplying such conversion price by a fraction of which the numerator shall be
the number of shares of Common Stock outstanding at the close of business on the
date fixed for such determination plus the number of shares of Common Stock
which the aggregate of the offering price of the total number of shares of
Common Stock so offered for subscription or purchase would purchase at such
current market price and the denominator shall be the number of shares of Common
Stock outstanding at the close of business on the date fixed for such
determination plus the number of shares of Common Stock so offered for
subscription or purchase, such reduction to become effective immediately after
the opening of business on the day following the date fixed for such
determination. For the purposes of this paragraph (2), the number of shares of
Common Stock at any time outstanding shall not include shares held in the
treasury of the Company but shall include shares issuable in respect of scrip
certificates issued in lieu of fractions of shares of Common Stock. The Company
shall not issue any rights, warrants or options in respect of shares of Common
Stock held in the treasury of the Company.

            (3) In case outstanding shares of Common Stock shall be subdivided
into a greater number of shares of Common Stock, the conversion price in effect
at the opening of business on the day following the day upon which such
subdivision becomes effective shall be proportionately reduced, and, conversely,
in case outstanding shares of Common Stock shall each be combined into a smaller
number of shares of Common Stock, the conversion price in effect at the opening
of business on the day following the day upon which such combination becomes
effective shall be proportionately increased, such reduction or increase, as the
case may be, to become effective immediately after the opening of business on
the day following the day upon which such subdivision or combination becomes
effective. 

            (4) Subject to the last sentence of this paragraph (4), in case the
Company shall, by dividend or otherwise, distribute to all holders of its Common
Stock evidences of its indebtedness, shares of any class of capital stock,
securities, cash or 


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property (excluding any rights, warrants or options referred to in paragraph (2)
of this Section 13.04, any dividend or distribution paid exclusively in cash and
any dividend or distribution referred to in paragraph (1) of this Section
13.04), the conversion price shall be reduced so that the same shall equal the
price determined by multiplying the conversion price in effect immediately prior
to the effectiveness of the conversion price reduction contemplated by this
paragraph (4) by a fraction of which the numerator shall be the current market
price per share (determined as provided in paragraph (7) of this Section) of the
Common Stock on the date of such effectiveness less the fair market value (as
determined in good faith by the Board of Directors, whose determination shall be
conclusive and described in a Board Resolution and shall, in the case of
securities being distributed for which prior thereto there is an actual or when
issued trading market, be no less than the value determined by reference to the
average of the closing prices in such market over the period specified in the
succeeding sentence), on the date of such effectiveness, of the portion of the
evidences of indebtedness, shares of capital stock, securities, cash and
property so distributed applicable to one share of Common Stock and the
denominator shall be such current market price per share of the Common Stock,
such reduction to become effective immediately prior to the opening of business
on the day next following the later of (a) the date fixed for the payment of
such distribution and (b) the date 20 days after the notice relating to such
distribution is given pursuant to Section 13.06(a) (such later date of (a) and
(b) being referred to as the "Reference Date"). If the Board of Directors
determines the fair market value of any distribution for purposes of this
paragraph (4) by reference to the actual or when issued trading market for any
securities comprising such distribution, it must in doing so consider the prices
in such market over the same period used in computing the current market price
per share pursuant to paragraph (7) of this Section. For purposes of this
paragraph (4), any dividend or distribution that includes shares of Common Stock
or rights, warrants or options to subscribe for or purchase shares of Common
Stock shall be deemed instead to be (a) a dividend or distribution of the
evidences of indebtedness, cash, property, shares of capital stock or securities
other than such shares of Common Stock or such rights, warrants or options
(making any conversion price reduction required by this paragraph (4))
immediately followed by (b) a dividend or distribution of such shares of Common
Stock or such rights, warrants or options (making any further conversion price
reduction required by paragraph (1) or (2) of this Section 13.04, except (i) the
Reference Date of such dividend or distribution as defined in this paragraph (4)
shall be substituted as "the date fixed for the determination of shareholders
entitled to receive such dividend or other distributions", "the date fixed for
the determination of shareholders entitled to receive such rights, warrants or
options" and "the date fixed for such determination" within the meaning of
paragraphs (1) and (2) of this Section 13.04 and (ii) any shares of Common Stock
included in such dividend or distribution shall not be deemed "soutstanding at
the close of business on the date fixed for such determination" within the
meaning of paragraph (1) of this Section 13.04).

            (5) In case the Company shall, by dividend or otherwise, make a
distribution to all holders of its Common Stock exclusively in cash in an
aggregate amount that, together with (i) the aggregate amount of any other
distributions to all holders of its Common Stock made exclusively in cash within
the 12 months preceding the date of payment of such distribution and in respect
of which no conversion price 


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adjustment pursuant to this paragraph (5) has been made and (ii) the aggregate
of any cash plus the fair market value (as determined in good faith by the Board
of Directors, whose determination shall be conclusive and described in a Board
Resolution), as of the expiration of the tender or exchange offer referred to
below, of consideration payable in respect of any tender or exchange offer by
the Company or a Subsidiary for all or any portion of the Common Stock concluded
within the 12 months preceding the date of payment of such distribution and in
respect of which no conversion price adjustment pursuant to paragraph (6) of
this Section 13.04 has been made, exceeds 12.5% of the product of the current
market price per share (determined as provided in paragraph (7) of this Section
13.04) of the Common Stock on the date fixed for shareholders entitled to
receive such distribution times the number of shares of Common Stock outstanding
on such date, the conversion price shall be reduced so that the same shall equal
the price determined by multiplying the conversion price in effect immediately
prior to the effectiveness of the conversion price reduction contemplated by
this paragraph (5) by a fraction of which the numerator shall be the current
market price per share (determined as provided in paragraph (7) of this Section
13.04) of the Common Stock on the due of such effectiveness less the amount of
cash so distributed applicable to one share of Common Stock and the denominator
shall be such current market price per share of the Common Stock, such reduction
to become effective immediately prior to the opening of business on the later of
(a) the day following the date fixed for the payment of such distribution and
(b) the date 20 days after the notice relating to such distribution is given
pursuant to Section 13.06(a). 

            (6) In case a successful tender or exchange offer made by the
Company or any Subsidiary for all or any portion of the Common Stock shall
involve an aggregate consideration having a fair market value (as determined in
good faith by the Board of Directors, whose determination shall be conclusive
and described in a Board Resolution) at the last time (the "Expiration Time")
tenders or exchanges may be made pursuant to such tender or exchange offer (as
it may be amended) that, together with (i) the aggregate of the cash plus the
fair market value (as determined in good faith by the Board of Directors, whose
determination shall be conclusive and described in a Board Resolution), as of
the expiration of the other tender or exchange offer referred to below, of
consideration payable in respect of any other tender or exchange offer by the
Company or a Subsidiary for all or any portion of the Common Stock concluded
within the preceding 12 months and in respect of which no conversion price
adjustment pursuant to this paragraph (6) has been made and (ii) the aggregate
amount of any distributions to all holders of the Common Stock made exclusively
in cash within the preceding 12 months and in respect of which no conversion
price adjustment pursuant to paragraph (5) of this Section 13.04 has been made,
exceeds 12.5% of the product of the current market price per share (determined
as provided in paragraph (7) of this Section 13.04) of the Common Stock on the
Expiration Time times the number of shares of Common Stock outstanding


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(including any tendered shares) on the Expiration Time, the conversion price
shall be reduced (but not increased) so that the same shall equal the price
determined by multiplying the conversion price in effect immediately prior to
the Expiration Time by a fraction of which the numerator shall be (i) the
product of the current market price per share (determined as provided in
paragraph (7) of this Section 13.04) of the Common Stock at the Expiration Time
times the number of shares of Common Stock outstanding (including any tendered
or exchanged shares) at the Expiration Time minus (ii) the fair market value
(determined as aforesaid) of the aggregate consideration payable to shareholders
based on the acceptance (up to any maximum specified in the terms of the tender
or exchange offer) of all shares validly tendered or exchanged and not withdrawn
as of the Expiration Time (the shares deemed so accepted, up to any such
maximum, being referred to as the "Purchased Shares") and the denominator shall
be the product of (i) such current market price per share at the Expiration Time
times (ii) such number of outstanding shares at the Expiration Time less the
number of Purchased Shares, such reduction to become effective immediately prior
to the opening of business on the day following the Expiration Time. 

            (7) For the purpose of any computation under this paragraph and
paragraphs (2), (4) and (5) of this Section 13.04, the current market price per
share of Common Stock on any date in question shall be deemed to be the average
of the daily Closing Prices for the 5 consecutive Trading Days selected by the
Company commencing not more than 20 Trading Days before, and ending not later
than, the date in question; provided, however, that (i) if the "ex" date (as
hereinafter defined) for any event (other than the issuance or distribution
requiring such computation) that requires an adjustment to the conversion price
pursuant to paragraph (1), (2), (3), (4), (5) or (6) above ("Other Event")
occurs on or after the 20th Trading Day prior to the date in question and prior
to the "ex" date for the issuance or distribution requiring such computation
(the "Current Event"), the Closing Price for each Trading Day prior to the "ex"
date for such Other Event shall be adjusted by multiplying such Closing Price by
the same fraction by which the conversion price is so required to be adjusted as
a result of such Other Event, (ii) if the "ex" date for any Other Event occurs
after the "ex" date for the Current Event and on or prior to the date in
question, the Closing Price for each Trading Day on and after the "ex" date for
such Other Event shall be adjusted by multiplying such Closing Price by the
reciprocal of the fraction by which the conversion price is so required to be
adjusted as a result of such Other Event, (iii) if the "ex" date for any Other
Event occurs on the "ex" date for the Current Event, one of those events shall
be deemed for purposes of clauses (i) and (ii) of this proviso to have an "ex"
date occurring prior to the "ex" date for the other event, and (iv) if the "ex"
date for the Current Event is on or prior to the date in question, after taking
into account any adjustment required pursuant to clause (ii) of this proviso,
the Closing Price for each Trading Day on or after such "ex" date shall be
adjusted by adding thereto the amount of any cash and the fair market value on
the date in question (as determined in good faith by the Board of Directors in a
manner consistent with any determination of such value for purposes of paragraph
(4) or (5) of this Section 13.04, whose determination shall be conclusive and
described in a Board Resolution) of the portion of the rights, warrants,
options, evidences of indebtedness, shares of capital stock, securities, cash or
property being distributed applicable to one share of Common Stock. For the
purpose of any computation under paragraph (6) of this Section 13.04, the
current market price per share of Common Stock on any date in question shall be
deemed to be the average of the daily Closing Prices for the 5 consecutive
Trading Days selected by the Company commencing on or after the latest (the
"Commencement Date") of (i) the date 20 Trading Days before the date in
question, (ii) the date of commencement of the tender or exchange offer
requiring such computation and (iii) the date of the last amendment, if any, of
such tender or exchange offer involving a change in the maximum number of 


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shares for which tenders are sought or a change in the consideration offered,
and ending not later than the date of the Expiration Time of such tender or
exchange offer (or, if such Expiration Time occurs before the close of trading
on a Trading Day, not later than the Trading Day immediately preceding the date
of such Expiration Time); provided, however, that if the "ex" date for any Other
Event (other than the tender or exchange offer requiring such computation)
occurs on or after the Commencement Date and on or prior to the date of the
Expiration Time for the tender or exchange offer requiring such computation, the
Closing Price for each Trading Day prior to the "ex" date for such Other Event
shall be adjusted by multiplying such Closing Price by the same fraction by
which the conversion price is so required to be adjusted as a result of such
other event. For purposes of this paragraph, the term "ex" date, (i) when used
with respect to any issuance or distribution, means the first date on which the
Common Stock trades regular way on the relevant exchange or in the relevant
market from which the Closing Price was obtained without the right to receive
such issuance or distribution, (ii) when used with respect to any subdivision or
combination of shares of Common Stock, means the first date on which the Common
Stock trades regular way on such exchange or in such market after the time at
which such subdivision or combination becomes effective, and (iii) when used
with respect to any tender or exchange offer means the first date on which the
Common Stock trades regular way on such exchange or in such market after the
Expiration Time of such tender or exchange offer. 

            (8) The Company may make such reductions in the conversion price, in
addition to those required by paragraphs (1), (2), (3), (4), (5) and (6) of this
Section, as it considers to be advisable in order that any event treated for
Federal income tax purposes as a dividend of stock or stock rights shall not be
taxable to the recipients. 

            (9) No adjustment in the conversion price shall be required unless
such adjustment would require an increase or decrease of at least 1% in the
conversion price; provided, however, that any adjustments which by reason of
this paragraph (9) are not required to be made shall be carried forward and
taken into account in any subsequent adjustment. 

            (10) In the event that the Company distributes rights or warrants
(other than those referred to in paragraph (2) above) pro rata to holders of
Common Stock, so long as any such rights or warrants have not expired or been
redeemed by the Company, the Company shall make proper provision so that the
Holder of any Security surrendered for conversion will be entitled to receive
upon such conversion, in addition to the Conversion Shares, a number of rights
and warrants to be determined as follows: (i) if such conversion occurs on or
prior to the date for the distribution to the holders of rights or warrants of
separate certificates evidencing such rights or warrants (the "Distribution
Date"), the same number of rights or warrants to which a holder of a number of
shares of Common Stock equal to the number of Conversion Shares is entitled at
the time of such conversion in accordance with the terms and provisions of and
applicable to the rights or warrants, and (ii) if such conversion occurs after
such Distribution Date, the same number of rights or warrants to which a holder
of the number of shares of Common Stock into which the principal amount of such
Security so converted was convertible immediately prior to such Distribution
Date would have been entitled on such 


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Distribution Date in accordance with the terms and provisions of and applicable
to the rights or warrants.

            SECTION 13.05. Notice of Adjustments of Conversion Price. Whenever
the conversion price is adjusted as herein provided:

            (a) the Company shall compute the adjusted conversion price in
accordance with Section 13.04 and shall prepare a certificate signed by the
Treasurer of the Company setting forth the adjusted conversion price and showing
in reasonable detail the facts upon which such adjustment is based, and such
certificate shall forthwith be filed (with a copy to the Trustee) at each office
or agency maintained for the purpose of conversion of Securities pursuant to
Section 10.02; and

            (b) a notice stating that the conversion price has been adjusted and
setting forth the adjusted conversion price shall forthwith be required, and as
soon as practicable after it is required, such notice shall be mailed by the
Company to all Holders at their last addresses as they shall appear in the
Security Register. 

            SECTION 13.06. Notice of Certain Corporate Action. In case:

            (a) the Company shall declare a dividend (or any other distribution)
on its Common Stock payable (i) otherwise than exclusively in cash or (ii)
exclusively in cash in an amount that would require a conversion price
adjustment pursuant to paragraph (5) of Section 13.04; or

            (b) the Company shall authorize the granting to the holders of its
Common Stock of rights, warrants or options to subscribe for or purchase any
shares of capital stock of any class or of any other rights (excluding employee
stock options); or 

            (c) of any reclassification of the Common Stock of the Company
(other than a subdivision or combination of its outstanding shares of Common
Stock), or of any consolidation or merger to which the Company is a party and
for which approval of any shareholders of the Company is required, or of the
sale or transfer of all or substantially all of the assets of the Company; or

            (d) of the voluntary or involuntary dissolution, liquidation or
winding up of the Company; or 

            (e) the Company or any Subsidiary of the Company shall commence a
tender or exchange offer for all or a portion of the Company's outstanding
shares of Common Stock (or shall amend any such tender or exchange offer); 

then the Company shall cause to be filed at each office or agency maintained for
the purpose of conversion of Securities pursuant to Section 10.02, and shall
cause to be mailed to all Holders at their last addresses as they shall appear
in the Security Register, at least 20 days (or 10 days in any case specified in
clause (a) or (b) above) prior to the applicable record, effective or expiration
date hereinafter specified, a notice stating (x) the date on which a record is
to be taken for the purpose of such dividend, distribution


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or granting of rights, warrants or options, or, if a record is not to be taken,
the date as of which the holders of Common Stock of record to be entitled to
such dividend, distribution, rights, warrants or options are to be determined,
or (y) the date on which such reclassification, consolidation, merger, sale,
transfer, dissolution, liquidation or winding up is expected to become
effective, and the date as of which it is expected that holders of Common Stock
of record shall be entitled to exchange their shares of Common Stock for
securities, cash or other property deliverable upon such reclassification.
consolidation, merger, safe, transfer, dissolution, liquidation or winding up,
or (z) the date on which such tender offer commenced, the date on which such
tender offer is scheduled to expire unless extended, the consideration offered
and the other material terms thereof (or the material terms of any amendment
thereto).

            SECTION 13.07. Company to Reserve Common Stock. The Company shall at
all times reserve and keep available, free from preemptive rights, out of its
authorized but unissued Common Stock, solely for the purpose of effecting the
conversion of Securities, the whole number of shares of Common Stock then
issuable upon the conversion in full of all outstanding Securities. 

            SECTION 13.08. Taxes on Conversions. The Company will pay any and
all taxes that may be payable in respect of the issue or delivery of shares of
Common Stock on conversion of Securities pursuant hereto. The Company shall not,
however, be required to pay any tax which may be payable in respect of any
transfer involved in the issue and delivery of shares of Common Stock in a name
other than that of the Holder of the Security or Securities to be converted, and
no such issue or delivery shall be made unless and until the Person requesting
such issue has paid to the Company the amount of any such tax, or has
established to the satisfaction of the Company that such tax has been paid.

            SECTION 13.09. Covenant as to Common Stock. The Company covenants
that all shares of Common Stock which may be issued upon conversion of
Securities will upon issue be newly issued (and not treasury shares) and be duly
authorized, validly issued, fully paid and nonassessable and, except as provided
in Section 13.08, the Company will pay all taxes, liens and charges with respect
to the issue thereof.

            SECTION 13.10. Cancellation of Converted Securities. All Securities
delivered for conversion shall be delivered to the Trustee to be cancelled by or
at the direction of the Trustee, which shall dispose of the same as provided in
Section 3.09.

            SECTION 13.11. Provisions in Case of Reclassification,
Consolidation, Merger or Sale of Assets. In the event that the Company shall be
a party to any transaction (including without limitation any (i)
recapitalization or reclassification of the Common Stock (other than a change in
par value, or from par value to no par value, or from no par value to par value,
or as a result of a subdivision or combination of the Common Stock), (ii) any
consolidation of the Company with, or merger of the Company into, any other
person, any merger of another person into the Company (other than a merger which
does not result in a reclassification, conversion, exchange or 


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cancellation of outstanding shares of Common Stock of the Company), (iii) any
sale or transfer of all or substantially all of the assets of the Company, or
(iv) any other transaction) pursuant to which the Common Stock is converted into
the right to receive other securities, cash or other property, then lawful
provision shall be made as part of the terms of such transaction whereby the
Holder of each Security then outstanding shall have the right thereafter to
convert such Security only into (subject to funds being legally available for
such purpose under applicable law at the time of such conversion) the kind and
amount of securities, cash and other properly receivable upon such transaction
by a holder of the number of shares of Common Stock into which such Security
might have been converted immediately prior to such transaction. The Company or
the person formed by such consolidation or resulting from such merger or which
acquired such assets or which acquired the Company's shares, as the case may be,
shall execute and deliver to the Trustee a supplemental indenture establishing
such rights. Such supplemental indenture shall provide for adjustments which,
for events subsequent to the effective date of such supplemental indenture,
shall be as nearly equivalent as may be practicable to the adjustments provided
for in this Article. The above provisions of this Section 13.11 shall similarly
apply to successive transactions of the foregoing type.

                                  ARTICLE XIV

                           Right to Require Repurchase

            SECTION 14.01. Right to Require Repurchase. In the event that there
shall occur a Change in Control (as defined in Section 14.06), then each Holder
shall have the right, at such Holder's option, to require the Company, subject
to the provisions of Section 12.03, to purchase all or any designated part of
such Holder's Securities on the date (the "Repurchase Date") fixed by the
Company that is not less than 30 days nor more than 45 days after the date the
Company gives notice of the Change in Control as contemplated in Section
14.02(a) at a price (the "Repurchase Price") equal to 100% of the principal
amount thereof, together with accrued and unpaid interest through the Repurchase
Date. Such right to require the repurchase of Securities shall not continue
after a discharge of the Company from its obligations with respect to the
Securities in accordance with Article IV or defeasance in accordance with
Section 15.01. Any requirements for notice, surrender or delivery of Securities
pursuant to this Article XIV shall, with respect to any Global Security, be
subject to any Applicable Procedures.

            SECTION 14.02. Notice, Method of Exercising Repurchase Right. (a) On
or before the 15th day after the Company knows or reasonably should know a
Change in Control has occurred, the Company, or at the written request of the
Company, the Trustee (in the name and at the expense of the Company), shall give
notice of the occurrence of the Change in Control and of the repurchase right
set forth herein arising as a result thereof by first-class mail, postage
prepaid, or by telefacsimile with written acknowledgement of transmittal to each
Holder of the Securities at such Holder's address appearing in the Security
Register. The Company shall also deliver a copy of such notice of a repurchase
right to the Trustee.

            Each notice of a repurchase right shall state:


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            (1) the Repurchase Date,

            (2) the date by which the repurchase right must be exercised,

            (3) the Repurchase Price, and

            (4) the instructions a Holder must follow to exercise its repurchase
      right. 

            No failure of the Company to give the foregoing notice shall limit
any Holder's right to exercise a repurchase right. The Trustee shall have no
affirmative obligation to determine if there shall have occurred a Change in
Control.

            (b) To exercise a repurchase right, a Holder shall deliver to the
Company (or an agent designated by the Company for such purpose in the notice
referred to in (a) above) and to the Trustee on or before the 30th day after the
date of transmittal of the notice referred to in (a) above (i) written notice of
the Holder's exercise of such right, which notice shall set forth the name of
the Holder, the principal amount of the Security or Securities (or portion of a
Security) to be repurchased, and a statement that an election to exercise the
repurchase right is being made thereby, and (ii) the Security or Securities with
respect to which the repurchase right is being exercised, duly endorsed for
transfer to the Company. Such written notice shall be irrevocable. If the
Repurchase Date falls between any Regular Record Date and the corresponding
succeeding Interest Payment Date, Securities to be repurchased must be
accompanied by payment from the Holder of an amount equal to the interest
thereon which the registered Holder thereof is to receive on such Interest
Payment Date.

            (c) In the event a repurchase right shall be exercised in accordance
with the terms hereof, the Company shall on the Repurchase Date pay or cause to
be paid in cash to the Holder thereof the Repurchase Price of the Security or
Securities as to which the repurchase right had been exercised. 

            SECTION 14.03. Deposit of Repurchase Price. On or prior to the
Repurchase Date, the Company shall deposit with the Trustee or with a Paying
Agent (or, if the Company is acting as its own Paying Agent, segregate and hold
in trust as provided in Section 10.03) an amount of money sufficient to pay the
Repurchase Price of the Securities which are to be repaid on the Repurchase
Date.

            SECTION 14.04. Securities Not Repurchased on Repurchase Date. If any
Security surrendered for repurchase shall not be so paid on the Repurchase Date,
the principal of such Security shall, until paid, bear interest from the
Repurchase Date at a rate borne by such Security.

            SECTION 14.05. Securities Repurchased in Part. Any Security which is
to be repurchased only in part shall be surrendered at any office or agency of
the Company designated for that purpose pursuant to Section 10.02 (with, if the
Company or the Trustee so requires, due endorsement by, or written instrument of
transfer in form satisfactory to the Company and the Trustee duly executed by,
the Holder thereof or his 


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attorney duly authorized in writing), and the Company shall execute, and the
Trustee shall authenticate and deliver to the Holder of such Security without
service charge, a new Security or Securities of any authorized denomination as
requested by such Holder, in aggregate principal amount equal to and in exchange
for the unrepurchased portion of the principal of the Security so surrendered.

            SECTION 14.06. Certain Definitions. For purposes of this Article:
The term "Beneficial Owner" shall be determined in accordance with Rules 13d-3
and 13d-5 promulgated by the Commission under the Exchange Act, or any successor
provision thereto, except that a Person shall be deemed to have "beneficial
ownership" of all shares that such Person has the right to acquire, whether such
right is exercisable immediately or only after the passage of time.

            A "Change in Control" shall be deemed to have occurred at such time
as (a) any Person, or any Persons acting together in a manner which would
constitute a "group" (a "Group") for purposes of Section 13(d) of the Exchange
Act, or any successor provision thereto, together with any Affiliates thereof,
(i) become the Beneficial Owners, directly or indirectly, of capital stock of
the Company, entitling such Person or Persons and its or their Affiliates to
exercise more than 50% of the total voting power of all classes of the Company's
capital stock entitled to vote generally in the election of directors or (ii)
shall succeed in having sufficient of its or their nominees (who are not
supported by a majority of the then current Board of Directors of the Company)
elected to the Board of Directors of the Company such that such nominees, when
added to any existing directors remaining on the Board of Directors of the
Company after such election who are Affiliates of or acting in concert with any
such Persons, shall constitute a majority of the Board of Directors of the
Company, (b) the Company shall be a party to any transaction pursuant to which
the Common Stock is converted into the right to receive other securities (other
than common stock), cash and/or property (or the Company, by dividend, tender or
exchange offer or otherwise, distributes other securities, cash and/or property
to holders of Common Stock) and the value of all such securities, cash and/or
property distributed in such transaction and any other transaction effected
within the 12 months preceding consummation of such transaction (as determined
in good faith by the Board of Directors, whose determination shall be conclusive
and described in a Board Resolution) is more than 50% of the average of the
daily Closing Prices for the five consecutive Trading Days ending on the Trading
Day immediately preceding the date of such transaction (or, if earlier, the
Trading Day immediately preceding the "ex" date (as defined in paragraph (7) of
Section 13.04) for such transaction) or (c) the Company shall consolidate with
or merge into any other Person or sell, convey, transfer or lease its properties
and assets substantially as an entirety to any Person other than a Subsidiary,
or any other Person shall consolidate with or merge into the Company (other
than, in the case of this clause (c), pursuant to any consolidation or merger
where Persons who are shareholders of the Company immediately prior thereto
become the Beneficial Owners of shares of capital stock of the surviving company
entitling such Persons to exercise more than 50% of the total voting power of
all classes of such surviving company's capital stock entitled to vote generally
in the election of directors).


                                       84
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                                   ARTICLE XV

                       Defeasance and Covenant Defeasance

            SECTION 15.01. Company's Option to Effect Defeasance or Covenant
Defeasance. The Company may at its option by Board Resolution, at any time,
elect to have either Section 15.02 or Section 15.03 applied to the Outstanding
Securities upon compliance with the conditions set forth below in this Article
XV.

            SECTION 15.02. Defeasance and Discharge. Upon the Company's exercise
of the option provided in Section 15.01 applicable to this Section, the Company
shall be deemed to have been discharged from their obligations with respect to
the Outstanding Securities (other than those specified below), the Holders and
any holders of Senior Indebtedness, and the provisions of Article XII hereof
shall cease to be effective, on the date the conditions set forth below are
satisfied (hereinafter, "defeasance"). For this purpose, such defeasance means
that the Company shall be deemed to have paid and discharged the entire
indebtedness represented by the Outstanding Securities, the Company shall be
deemed to have satisfied all their other obligations under such Securities and
this Indenture insofar as such Securities are concerned (and the Trustee, at the
expense of the Company, shall execute proper instruments acknowledging the
same), except for the following which shall survive until otherwise terminated
or discharged hereunder: (A) the rights of Holders of such Securities to
receive, solely from the trust fund described in Section 15.04 and as more fully
set forth in such Section, payments in respect of the principal of, premium, if
any and interest on such Securities when such payments are due, (B) the
Company's obligations with respect to such Securities under Sections 3.04, 3.05,
3.06, 10.02, 10.03, 10.11, Article XIII and Article XIV, (C) the rights, powers,
trusts, duties and immunities of the Trustee hereunder and (D) this Article XV.
Subject to compliance with this Article XV, the Company may exercise its option
under this Section 15.02 notwithstanding the prior exercise of its option under
Section 15.03.

            SECTION 15.03. Covenant Defeasance. Upon the Company's exercise of
the option provided in Section 15.01 applicable to this Section, (i) the Company
shall be released from its obligations under Section 10.06 and Section 10.07,
(ii) the occurrence of an event specified in Section 5.01(3) (with respect to
either of Section 10.06 or Section 10.07) and 5.01(4) shall not be deemed to be
an Event of Default and (iii) the provisions of Article XII hereof shall cease
to be effective on and after the date the conditions set forth below are
satisfied (hereinafter, "covenant defeasance"). For this purpose, such covenant
defeasance means that the Company may omit to comply with and shall have no
liability in respect of any term, condition or limitation set forth in any such
Section or Article, whether directly or indirectly by reason of any reference
elsewhere herein to any such Section or Article or by reason of any reference in
any such Section or Article to any other provision herein or in any other
document, but the remainder of this Indenture and such Securities shall be
unaffected thereby.


                                       85
   93

            SECTION 15.04. Conditions to Defeasance or Covenant Defeasance. The
following shall be the conditions to application of either Section 15.02 or
Section 15.03 to the then Outstanding Securities:

            (1) The Company shall irrevocably have deposited or caused to be
      deposited with the Trustee (or another trustee satisfying the requirements
      of Section 6.09 who shall agree to comply with the provisions of this
      Article XV applicable to it) as trust funds in trust for the purpose of
      making the following payments, specifically pledged as security for, and
      dedicated solely to, the benefit of the Holders of such Securities, (A)
      money in an amount, or (B) U.S. Government Obligations which through the
      scheduled payment of principal and interest in respect thereof in
      accordance with their terms will provide, not later than one day before
      the due date of any payment, money in an amount, or (C) a combination
      thereof, sufficient, in the written opinion of a nationally recognized
      firm of independent public accountants expressed in a written
      certification thereof delivered to the Trustee, to pay and discharge, and
      which shall be applied by the Trustee (or other qualifying trustee) to pay
      and discharge, the principal of, premium, if any, and each installment of
      interest on the Securities on the Stated Maturity of such principal or
      installment of interest in accordance with the terms of this Indenture and
      of such Securities. For this purpose, "U.S. Government Obligations" means
      securities that are (x) direct obligations of the United States of America
      for the payment of which its full faith and credit is pledged or (y)
      obligations of a Person controlled or supervised by and acting as an
      agency or instrumentality of the United States of America the payment of
      which is unconditionally guaranteed as a full faith and credit obligation
      by the United States of America, which, in either case, are not callable
      or redeemable at the option of the issuer thereof, and shall also include
      a depository receipt issued by a bank (as defined in Section 3(a)(2) of
      the Securities Act of 1933, as amended) as custodian with respect to any
      such U.S. Government Obligation or a specific payment of principal of or
      interest on any such U.S. Government Obligation held by such custodian for
      the account of the holder of such depository receipt, provided that
      (except as required by law) such custodian is not authorized to make any
      deduction from the amount payable to the holder of such depository receipt
      from any amount received by the custodian in respect of the U.S.
      Government Obligation or the specific payment of principal of or interest
      on the U.S. Government Obligation evidenced by such depository receipt.

            (2) In the case of an election under Section 15.02, the Company
      shall have delivered to the Trustee an Opinion of Counsel stating that (x)
      the Company has received from, or there has been published by, the
      Internal Revenue Service a ruling, or (y) since the date of this Indenture
      there has been a change in the applicable Federal income tax law, in
      either case to the effect that, and based thereon such opinion shall
      confirm that, the Holders of the Outstanding Securities will not recognize
      gain or loss for Federal income tax purposes as a result of such deposit,
      defeasance and discharge and will be subject to Federal income tax on the
      same amount, in the same manner and at the same times as would have been
      the case if such deposit, defeasance and discharge had not occurred. 


                                       86
   94

            (3) In the case of an election under Section 15.03, the Company
      shall have delivered to the Trustee an Opinion of Counsel to the effect
      that the Holders of the Outstanding Securities will not recognize gain or
      loss for Federal income tax purposes as a result of such deposit and
      covenant defeasance and will be subject to Federal income tax on the same
      amount, in the same manner and at the same times as would have been the
      case if such deposit and covenant defeasance had not occurred. 

            (4) The Company shall have delivered to the Trustee an Officer's
      Certificate to the effect that the Securities, if then listed on any
      securities exchange, will not be delisted as a result of such deposit. 

            (5) Such defeasance or covenant defeasance shall not cause the
      Trustee to have a conflicting interest as defined in Section 6.08 and for
      purposes of the Trust Indenture Act with respect to any securities of the
      Company. 

            (6) At the time of such deposit: (A) no default in the payment of
      all or a portion of principal of (or premium, if any) or interest on or
      other obligations in respect of any Senior Indebtedness shall have
      occurred and be continuing, and no event of default with respect to any
      Senior Indebtedness shall have occurred and be continuing and shall have
      insulted in such Senior Indebtedness becoming or being declared due and
      payable prior to the date on which it would otherwise have become due and
      payable and (B) no other event with respect to any Senior Indebtedness
      shall have occurred and be continuing permitting (after notice or the
      lapse of time, or both) the holders of such Senior Indebtedness (or a
      trustee on behalf of the holders thereof) to declare such Senior
      Indebtedness due and payable prior to the date on which it would otherwise
      have become due and payable, or, in the case of either Clause (A) or
      Clause (B) above, each such default or event of default shall have been
      cured or waived or shall have ceased to exist. 

            (7) No Event of Default or event which with notice or lapse of time
      or both would become an Event of Default shall have occurred and be
      continuing on the date of such deposit or, insofar as subsections 5.01(6)
      and (7) are concerned, at any time during the period ending on the 121st
      day after the date of such deposit (it being understood that this
      condition shall not be deemed satisfied until the expiration of such
      period). 

            (8) Such defeasance or covenant defeasance shall not result in a
      breach or violation of, or constitute a default under, any other agreement
      or instrument to which the Company is a party or by which it is bound. 

            (9) The Company shall have delivered to the Trustee an Officers'
      Certificate and an Opinion of Counsel, each stating that all conditions
      precedent provided for relating to either the defeasance under Section
      15.02 or the covenant defeasance under Section 15.03 (as the case may be)
      have been complied with. 


                                       87
   95

            (10) Such defeasance or covenant defeasance shall not result in the
      trust arising from such deposit constituting an investment company as
      defined in the Investment Company Act of 1940, as amended, or such trust
      shall be qualified under such act or exempt from regulation thereunder.
      
            SECTION 15.05. Deposited Money and U.S. Government Obligations to Be
Held in Trust; Other Miscellaneous Provisions. Subject to the provisions of the
last paragraph of Section 10.03, all money and U.S. Government Obligations
(including the proceeds thereof) deposited with the Trustee (or other qualifying
trustee - collectively, for purposes of this Section 15.05, the "Trustee")
pursuant to Section 15.04 in respect of the Securities shall be held in trust
and applied by the Trustee, in accordance with the provisions of such Securities
and this Indenture, to the payment, either directly or through any Paying Agent
(including the Company acting as its own Paying Agent) as the Trustee may
determine, to the Holders of such Securities, of all sums due and to become due
thereon in respect of principal, premium, if any, and interest. Money so held in
trust shall not be subject to the provisions of Article XII.

            The Company shall pay and indemnify the Trustee against any tax, fee
or other charge imposed on or assessed against the U.S. Government Obligations
deposited pursuant to Section 15.04 or the principal and interest received in
respect thereof other than any such tax, fee or other charge which by law is for
the account of the Holders of the Outstanding Securities.

            Anything in this Article XV to the contrary notwithstanding, the
Trustee shall deliver or pay to the Company from time to time upon Company
Request any money or U.S. Government Obligations held by it as provided in
Section l5.04 which, in the opinion of a nationally recognized firm of
independent public accountants expressed in a written certification thereof
delivered to the Trustee, are in excess of the amount thereof which would then
be required to be deposited to effect an equivalent defeasance or covenant
defeasance.

            SECTION 15.06. Reinstatement. If the Trustee or the Paying Agent is
unable to apply any money in accordance with Section 15.02 or 15.03 by reason of
any order or judgment of any court or governmental authority enjoining,
restraining or otherwise prohibiting such application, then the Company's
obligations under this Indenture and the Securities shall be revived and
reinstated as though no deposit had occurred pursuant to this Article XV until
such time as the Trustee or Paying Agent is permitted to apply all such money in
accordance with Section 15.02 or 15.03; provided, however, that if the Company
makes any payment of principal of, premium, if any, or interest on any Security
following the reinstatement of its obligations, the Company shall be subrogated
to the rights of the Holders of such Securities to receive such payment from the
money held by the Trustee or the Paying Agent.


                                       88
   96

                                  ARTICLE XVI

                                    Immunity

            SECTION 16.01. Personal Immunity of Incorporators, Shareholders,
Directors and Officers. No recourse for the payment of the principal of or
interest on the Securities, and no recourse under or upon any obligation,
covenant or agreement contained in this Indenture or in any indenture
supplemental hereto, or in the Securities, or because of any indebtedness
evidenced thereby, shall be had against any incorporator, or against any past,
present or future shareholder, officer or director, as such, of the Company or
any successor corporation, either directly or through the Company or any
successor corporation, under any rule of law, statute or constitutional
provision or by the enforcement of any assessment or by any legal or equitable
proceeding or otherwise, all such liability being expressly waived and released
by the acceptance of the Securities by the Holders thereof and as part of the
consideration for the issue of the Securities. Each and every Holder of the
Securities, by receiving and holding the same, agrees to the provisions of this
Section 16.01 and waives and releases any and all such recourse, claim and
liability.

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

            This instrument may be executed in any number of counterparts, each
of which so executed shall be deemed to be an original, but all such
counterparts shall together constitute but one and the same instrument.

            IN WITNESS WHEREOF, the parties hereto have caused this Indenture to
be duly executed, and their respective corporate seals to be hereunto affixed
and attested, all as of the day and year first above written.


                                       89
   97

                              SPACEHAB, INCORPORATED


                              By
                                 ------------------------------------------
                                 Name:    Margaret E.  Grayson
                                 Title:   Vice President of Finance (CFO), 
                                          Treasurer & Assistant Secretary
Attest:


by
  --------------------------------
   Name:

   98

COMMONWEALTH OF VIRGINIA      )
                              ) ss.:
COUNTY OF FAIRFAX             )

            On the _____ day of October, 1997, before me personally came
Margaret E. Grayson, to me known, who, being by me duly sworn, did depose and
say that she is Vice President of Finance (CFO), Treasurer and Assistant
Secretary of SPACEHAB, Incorporated, one of the corporations described in and
which executed the foregoing instrument; that she knows the seal of said
corporation; that the seal affixed to said instrument is such corporate seal;
that it was so affixed by authority of the Board of Directors of said
corporation, and that she signed her name thereto by like authority.


                                 --------------------------------
                                          Notary Public

   99

                                    FIRST UNION NATIONAL BANK


                                    By
                                       --------------------------------------
                                       Name:    Dante M.  Monakil
                                       Title:   Vice President


Attest:


by
  -----------------------------
   Name:


   100


COMMONWEALTH OF VIRGINIA      )
                              ) ss.:
COUNTY OF RICHMOND            )

            On the 21st day of October, 1997, before me personally came Dante M.
Monakil, to me known, who, being by me duly sworn, did depose and say that he is
a Vice President of First Union National Bank, one of the corporations described
in and which executed the foregoing instrument; that he knows the seal of said
corporation; that the seal affixed to said instrument is such corporate seal;
that it was so affixed by authority of the Board of Directors of said
corporation, and that he signed his name thereto by like authority.


                                 -----------------------------------
                                          Notary Public