<PAGE>   1
                                                                     EXHIBIT 4.8




                            LIBERTY MEDIA CORPORATION

                                       AND

                              THE BANK OF NEW YORK

                                     Trustee

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

                          FIFTH SUPPLEMENTAL INDENTURE

                             dated January 11, 2001

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

                           Supplementing the Indenture

                            dated as of July 7, 1999

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

                 3-1/2% Senior Exchangeable Debentures due 2031
<PAGE>   2
         FIFTH SUPPLEMENTAL INDENTURE, dated the 11th day of January, 2001,
between LIBERTY MEDIA CORPORATION, a corporation existing under the laws of the
State of Delaware (the "Company"), and THE BANK OF NEW YORK, a New York banking
corporation, having its principal corporate trust office in The City of New
York, New York, as trustee (the "Trustee").

         WHEREAS, the Company has heretofore executed and delivered to the
Trustee an Indenture dated as of July 7, 1999 (the "Original Indenture" and, as
supplemented to the date hereof, the "Indenture"), providing for the issuance by
the Company from time to time of its senior debt securities to be issued in one
or more series (in the Original Indenture and herein called the "Securities");

         WHEREAS, the Company, in the exercise of the power and authority
conferred upon and reserved to it under the provisions of the Original Indenture
and pursuant to appropriate resolutions of the Board of Directors, has duly
determined to make, execute and deliver to the Trustee this Fifth Supplemental
Indenture to the Original Indenture in order to establish the form and terms of,
and to provide for the creation and issue of, a series of Securities designated
as the "3-1/2% Senior Exchangeable Debentures due 2031" under the Original
Indenture in an aggregate principal amount of up to $600,000,000 (the
"Debentures");

         WHEREAS, Section 901 of the Original Indenture provides, among other
things, that the Company, when authorized by a Board Resolution, and the
Trustee, at any time and from time to time, without the consent of any Holders,
may enter into an indenture supplemental to the Original Indenture to establish
the terms of Securities of any series as permitted by Sections 201 and 301 of
the Original Indenture; and

         WHEREAS, all things necessary to make the Securities, when executed by
the Company and authenticated and delivered by the Trustee or any Authenticating
Agent and issued upon the terms and subject to the conditions hereinafter and in
the Indenture set forth against payment therefor, the valid, binding and legal
obligations of the Company and to make this Fifth Supplemental Indenture a
valid, binding and legal agreement of the Company, have been done.

         NOW, THEREFORE, THIS FIFTH SUPPLEMENTAL INDENTURE WITNESSETH that, in
order to establish the terms of the series of Securities designated as the
"3-1/2% Senior Exchangeable Debentures due 2031," and for and in consideration
of the premises and of the covenants contained in the Original Indenture and in
this Fifth Supplemental Indenture and for other good and valuable consideration
the receipt and sufficiency of which are hereby acknowledged, it is mutually
covenanted and agreed as follows:
<PAGE>   3
                                  ARTICLE ONE

                              DEFINITIONS AND OTHER

                        PROVISIONS OF GENERAL APPLICATION

         Section 101. Definitions.

         Each capitalized term that is used herein and is defined in the
Original Indenture shall have the meaning specified in the Original Indenture
unless such term is otherwise defined herein, in which case such term shall have
the meaning specified herein.

         "Additional Distribution" shall mean any distribution to Holders of the
Debentures made pursuant to Section 206 in respect of a Reference Share
Distribution.

         "Adjusted Principal Amount" shall mean, for each $1,000 Original
Principal Amount of the Debentures, $1,000, minus any and all Extraordinary
Additional Distributions and any Yield Adjustments made in respect to such
Original Principal Amount of Debentures pursuant to Section 204.

         "Average Transaction Consideration" shall mean, with respect to a
holder of one Reference Share in a Reference Share Offer, (a) the aggregate
consideration actually paid or distributed in respect of all Reference Shares
accepted in such Reference Share Offer, divided by (b) the total number of
Reference Shares outstanding immediately prior to the expiration of the
Reference Share Offer and entitled to participate in such Reference Share Offer.

         "Business Day" shall mean any day that is not a Saturday, Sunday or
legal holiday, on which banking institutions or trust companies in The City of
New York are authorized or obligated by law or regulation to close.

         "Closing Price" shall mean, with respect to any security on any date of
determination, the closing sale price (or, if no closing sale price is reported,
the last reported sale price) of that security (regular way) on the New York
Stock Exchange on that date or, if the security is not listed for trading on the
New York Stock Exchange on that date, as reported in the composite transactions
for the principal United States national or regional securities exchange on
which the security is so listed, or if the security is not so listed on a United
States national or regional securities exchange, as reported by the Nasdaq
National Market or, if the security is not so reported, the last quoted bid
price for the security in the over-the-counter market as reported by the
National Quotation Bureau or a similar organization. In the event that no such
quotation is available for that day, the Board of Directors will be entitled to
determine the Closing Price on the basis of those quotations that it in good
faith considers appropriate, unless "Closing Price" is to be determined for
purposes of valuing securities to be distributed pursuant to a Reference Share
Distribution and such securities have an aggregate value in excess of
$100,000,000, in which event the Closing Price will be determined by a
nationally recognized investment banking or appraisal firm appointed by the
Company for such purpose. With respect to options, warrants and other rights to
purchase a security, the Closing Price shall be the value of the underlying
security determined as aforesaid, minus the exercise price; and with respect to
securities exchangeable for or convertible into a relevant security, the Closing
Price shall be the Closing



                                       1
<PAGE>   4
Price of the exchangeable or convertible security determined as aforesaid or, if
it has no Closing Price, the fully converted value based upon the Closing Price
of the underlying security determined as aforesaid. If an "ex-dividend" date for
a security occurs during the period used in determining the security's Current
Market Value or Exchange Market Value, the Closing Price of the security on any
day prior to the "ex-dividend" date used in such determination shall be reduced
by the amount of the dividend. For this purpose, the amount of a non-cash
dividend will be equal to the amount of the dividend, as of the record date
therefor, as determined by a nationally recognized investment banking firm
retained by the Company for this purpose. To the extent that trading (regular
way) of, or quotations for, any security as to which "Closing Price" is to be
determined continues past 4:00 p.m., New York City time, on the applicable
securities exchange, the National Market System or over-the-counter market, as
the case may be, "Closing Price" shall be deemed to refer to the price or bid at
the time that is then customary for determining the trading day's index levels
for stocks traded on such securities exchange, the National Market System or
over-the-counter market.

         "Common Equity Securities" shall mean any securities (i) that are
common stock or participate without limitation in earnings and dividends in
parity with common stock and (ii) that are Marketable Securities. For greater
certainty, the term "Common Equity Securities" does not mean warrants, options
or other rights to purchase, or securities exchangeable or convertible into,
Common Equity Securities.

         "Company" shall mean 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 the Indenture, and thereafter "Company"
shall mean such successor Person, and any other obligor upon the Debentures.

         "Current Market Value" shall mean, with respect to any Reference Share,
the average of the Closing Prices for such Reference Share over the 20 Trading
Day period immediately prior to (but not including) the fifth Trading Day
preceding the applicable Redemption Date (or, in the case of Section 204(b),
Stated Maturity).

         "Debenture" shall mean $1,000 Original Principal Amount of the
Debentures.

         "Debentures" shall mean the Company's 3-1/2% Senior Exchangeable
Debentures due 2031.

         "Depository" shall have the meaning assigned to it in the Original
Indenture.

         "DTC" shall mean The Depository Trust Company.

         "Excess Regular Cash Dividend Amount" shall mean the amount, if any, by
which aggregate Regular Cash Dividends paid during any Interest Period to a
holder of the number of Reference Shares attributable to a Debenture exceeds
$2.9455.

         "Excess Regular Cash Dividend Amount Distribution" shall mean any
Additional Distribution made to Holders of the Debentures pursuant to Section
206 in respect of an Excess Regular Cash Dividend Amount.


                                       2
<PAGE>   5
         "Exchange Agent" shall mean any Person authorized by the Company to act
as Exchange Agent under the Indenture. The Company initially authorizes the
Trustee to act as Exchange Agent for the Debentures on its behalf. The Company
may at any time and from time to time authorize one or more Persons (including
the Company) to act as Exchange Agent in addition to or in place of the Trustee
with respect to the Debentures.

         "Exchange Date" shall mean, with respect to any Notice of Exchange, the
date on which the Notice of Exchange and all documents, instruments and payments
required to be tendered in connection with the related exchange have been
received by the Exchange Agent.

         "Exchange Market Value" shall mean, for each Reference Share
attributable to the Debentures at the date of determination, (a) in the case of
a Notice of Exchange delivered to the Exchange Agent prior to January 15, 2002,
the Closing Price for such Reference Share on the twentieth Trading Day
immediately following the Exchange Date (unless more than $1,000,000 aggregate
Original Principal Amount of Debentures have been validly tendered for exchange
on such date, in which case Exchange Market Value shall mean the average of the
Closing Prices for such Reference Share over the five Trading Day period ending
on the twentieth Trading Day immediately following the Exchange Date); and (b)
in the case of a Notice of Exchange delivered to the Exchange Agent on or after
January 15, 2002, the Closing Price for such Reference Share on the Trading Day
immediately following the Exchange Date (unless more than $1,000,000 aggregate
Original Principal Amount of Debentures have been validly tendered for exchange
on such date, in which case the Exchange Market Value shall mean the average of
the Closing Prices for such Reference Share over the five Trading Day period
immediately following the Exchange Date). The aggregate Exchange Market Value of
the Reference Shares attributable to any Debenture for which a Notice of
Exchange is delivered to the Trustee shall equal the sum of the Exchange Market
Values of the Reference Shares attributable to such Debenture.

         "Extraordinary Additional Distribution" shall mean any Additional
Distribution other than an Excess Regular Cash Dividend Amount Distribution,
whether of cash or property; provided that in the event of a Reference Share
Offer, the amount of the Extraordinary Additional Distribution on each Debenture
in respect of such Reference Share Offer shall equal the portion of the Average
Transaction Consideration deemed to be received on the Reference Shares of the
class or series subject to the Reference Share Offer attributable to such
Debenture (immediately prior to giving effect to the Reference Share
Proportionate Reduction relating to that Reference Share Offer) other than the
portion of the Average Transaction Consideration that consists of Common Equity
Securities, which themselves become part of the Reference Shares as a result of
the Reference Share Offer Adjustment.

         "Extraordinary Distribution" shall mean any Reference Share
Distribution other than a Regular Cash Dividend. For greater certainty, the term
"Extraordinary Distribution" does not include an Excess Regular Cash Dividend
Amount Distribution.

         "Final Period Distribution" shall mean, for each Debenture, (a) all
Excess Regular Cash Dividend Amount Distributions on any Reference Shares
attributable to such Debenture for which the ex-dividend date has occurred but
which, at the date of determination, have not been received by the holders of
such Reference Shares and (b) all Extraordinary Distributions on any

                                       3
<PAGE>   6
Reference Shares attributable to such Debenture for which the ex-dividend date
has occurred but which, at the date of determination, have not been received by
the holders of such Reference Shares, but only to the extent that the value of
such Extraordinary Distributions (determined in accordance with Section 206(d)
or (e)) exceeds the Adjusted Principal Amount of such Debenture.

         "Initial Purchaser" shall mean Lehman Brothers Inc.

         "Interest Payment Date" shall have the meaning assigned to it in
Section 205.

         "Interest Period" shall mean each period from and including the most
recent Interest Payment Date or, if no interest has been paid on the Debentures,
from and including the issue date of the Debentures, to but excluding the next
applicable Interest Payment Date or the Stated Maturity of the principal of the
Debentures.

         "Maturity Repayment Amount" shall have the meaning assigned to it in
the form of Debenture attached hereto as Exhibit A.

         "Motorola, Inc." shall mean Motorola, Inc. a Delaware corporation.

         "Motorola Stock" shall mean the common stock of Motorola, Inc., par
value $3.00 per share.

         "Notice of Exchange" shall mean the notice of exchange given to the
Exchange Agent by a Holder of its request to exchange Debentures pursuant to
Section 209(c).

         "Optional Redemption" shall mean any redemption of the Debentures, in
whole or in part, at the option of the Company pursuant to Section 208(a).

         "Original Principal Amount" shall mean the face value of $1,000
principal amount per Debenture.

         "Permanent Regulation S Debenture" shall have the meaning assigned to
it in Section 215(c).

         "Reference Company" shall mean Motorola, Inc., for so long as any
Reference Shares are Motorola Stock, and any other issuer of a Reference Share.


         "Reference Share" shall initially mean one share of Motorola Stock; and
after the date hereof shall mean and include each share or fraction of a share
of Common Equity Securities received by a holder of a Reference Share in respect
of that Reference Share, and, to the extent the Reference Share remains
outstanding after any of the following events but without duplication, including
the Reference Share outstanding immediately prior thereto, in each case directly
or as the result of successive applications of this paragraph upon any of the
following events: (i) a distribution on or in respect of a Reference Share, made
in Reference Shares; (ii) the combination of a Reference Share into a smaller
number of shares or other units; (iii) the subdivision of outstanding shares or
other units of a Reference Share; (iv) the conversion or reclassification of
Reference Shares by issuance or exchange of other Common Equity

                                       4
<PAGE>   7
Securities; (v) any Common Equity Securities issued for a Reference Share in any
consolidation or merger of a Reference Company, or any surviving entity or
subsequent surviving entity of a Reference Company (referred to herein as a
"Reference Company Successor"), with or into another entity (other than any
Common Equity Securities issued in connection with (A) a Reference Share Offer
or (B) a merger or consolidation in which (x) the Reference Company is the
continuing corporation and in which the Reference Shares outstanding immediately
prior to the merger or consolidation are not exchanged for cash, securities or
other property of the Reference Company or another corporation or (y) an
election is given as to the consideration to be received by a holder of
Reference Shares); (vi) any Common Equity Securities issued in exchange for a
Reference Share in any statutory exchange of securities of a Reference Company
or any Reference Company Successor with another corporation (other than any
Common Equity Securities issued in connection with (A) a Reference Share Offer
or (B) a statutory exchange of securities in which (x) the Reference Company is
the continuing corporation and in which the Reference Shares outstanding
immediately prior to the statutory exchange are not exchanged for cash,
securities or other property of the Reference Company or another corporation or
(y) an election is given as to the consideration to be received by a holder of
Reference Shares); (vii) any Common Equity Securities issued with respect to a
Reference Share in connection with any liquidation, dissolution or winding up of
the Reference Company or any Reference Company Successor; and (viii) any Common
Equity Securities received in exchange for a Reference Share as part of the
Average Transaction Consideration deemed received in any Reference Share Offer.

         "Reference Share Distribution" shall mean any dividend or distribution
on or in respect of the Reference Shares, including payments and distributions
in connection with (i) the consolidation or merger of a Reference Company or
Reference Company Successor, a statutory exchange of securities of a Reference
Company or Reference Company Successor or a liquidation or dissolution of a
Reference Company or Reference Company Successor or (ii) any Reference Share
Offer, but shall not include any dividend or distribution made in the form of
additional Reference Shares.

         "Reference Share Offer" shall mean any tender offer or exchange offer
made for 30% or more of the outstanding shares of a class or series of Reference
Shares of a Reference Company or any consolidation, merger or statutory exchange
involving a class or series of Reference Shares of a Reference Company in which
an election is given to holders of such Reference Shares as to the consideration
to be received in the transaction.

         "Reference Share Offer Adjustment" shall mean (a) an adjustment to the
Reference Shares attributable to each Debenture involved in a Reference Share
Offer to include the portion of the Average Transaction Consideration received
in such Reference Share Offer that consists of Reference Shares, and (b) a
reduction in the number of Reference Shares attributable to each Debenture
involved in a Reference Share Offer immediately prior to such Reference Share
Offer by the Reference Share Proportionate Reduction.

         "Reference Share Proportionate Reduction" shall mean a proportionate
reduction in the number of Reference Shares which are the subject of the
applicable Reference Share Offer and attributable to each Debenture, calculated
in accordance with the following formula:


                                       5
<PAGE>   8
                                          X
                                      R = -
                                          N




where:

         R =      the fraction by which the number of Reference Shares of the
                  class or series of Reference Shares subject to the Reference
                  Share Offer and attributable to each Debenture will be
                  reduced;

         X =      the aggregate number of Reference Shares of the class or
                  series of Reference Shares subject to the Reference Share
                  Offer accepted in the Reference Share Offer; and

         N =      the aggregate number of Reference Shares of the class or
                  series of Reference Shares subject to the Reference Share
                  Offer outstanding immediately prior to the expiration of the
                  Reference Share Offer.

         "Registration Default" shall mean either (a) the Shelf Registration
Statement is not filed with the Securities and Exchange Commission on or prior
to the 180th calendar day following the date of original issuance of the
Debentures or (b) such Shelf Registration Statement has not been declared
effective on or prior to the 270th calendar day following the date of original
issuance of the Debentures.

         "Registration Rights Agreement" shall mean the Registration Rights
Agreement, dated as of January 11, 2001, between the Company and the Initial
Purchaser.

         "Registration Suspension" shall mean any period of more than an
aggregate of 30 calendar days in any consecutive twelve-month period, occurring
after the Shelf Registration Statement has been declared effective, during which
such Shelf Registration Statement is not usable as contemplated by the
Registration Rights Agreement.

         "Regular Cash Dividend" shall mean any cash dividend declared and paid
or payable by a Reference Company on its Reference Shares in accordance with the
Reference Company's publicly announced regular common equity dividend policy.

         "Regulation S" shall mean Regulation S under the Securities Act.

         "Restricted Period" shall have the meaning assigned to it in Section
207.

         "Rule 144A" shall mean Rule 144A under the Securities Act, as such rule
may be amended from time to time.

         "Rule 144A Debentures" shall have the meaning assigned to it in Section
215.

         "Securities Act" shall mean the United States Securities Act of 1933,
as amended.

         "Securities Exchange Act" shall mean the United States Securities
Exchange Act of 1934, as amended.


                                       6
<PAGE>   9
         "Shelf Registration Statement" shall mean the registration statement
required to be filed by the Company pursuant to the Registration Rights
Agreement.

         "Tax Event" shall mean that the Trustee shall have received an opinion
of nationally recognized independent tax counsel experienced in such matters to
the effect that as a result of (a) any amendment to, clarification of, or change
in the laws, or any regulations thereunder, of the United States or any
political subdivision or taxing authority thereof or therein, or (b) any
judicial decision, official administrative pronouncement, ruling, regulatory
procedure, interpretation, notice or announcement, including any notice or
announcement of proposed procedures or regulations, in each case, on or after
January 4, 2001 (a "change in tax law"), there is the creation by such change in
tax law of a substantial risk that, pursuant to Section 263(g) of the Internal
Revenue Code, the Company will not be able to deduct all of the interest
(including original issue discount) paid or accrued with respect to the
Debentures in calculating its U.S. federal income tax liability.

         "Tax Event Redemption" shall mean the redemption of the Debentures
pursuant to Section 208(b) following the occurrence of a Tax Event.

         "Temporary Regulation S Debenture" shall have the meaning assigned to
it in Section 215(c).

         "Trading Day" shall mean (i) where the Closing Price of a security is
to be determined, a day on which the security (a) is not suspended from trading
or quotation at the close of business on the national or regional securities
exchange, the National Market System or over-the-counter market that is the
primary market for the trading or quotation of that security and (b) has traded
or been quoted at least once on the national or regional securities exchange,
the National Market System or over-the-counter market that is the primary market
for the trading or quotation of that security and (ii), for any other purpose
under this Fifth Supplemental Indenture, any day on which the Nasdaq National
Market and the New York Stock Exchange are open for the transaction of business.

         "Yield Adjustment" shall mean any adjustment required to be made to the
Adjusted Principal Amount on any Interest Payment Date following any
Extraordinary Additional Distribution (except for the Interest Payment Date
immediately following such Extraordinary Additional Distribution) so that the
interest payment on such Interest Payment Date does not represent an annualized
yield in excess of 3-1/2% on the Adjusted Principal Amount of the Debentures
during the semi-annual period immediately preceding such Interest Payment Date.

         Section 102. Section References.

         Each reference to a particular section set forth in this Fifth
Supplemental Indenture shall, unless the context otherwise requires, refer to
this Fifth Supplemental Indenture.

         Section 103. Conflict with Original Indenture.

         To the extent that any of the terms set forth in this Fifth
Supplemental Indenture or the certificates representing the Debentures shall
conflict with any of the terms of the Original Indenture, the terms of this
Fifth Supplemental Indenture and the certificates representing the

                                       7
<PAGE>   10
Debentures shall be controlling with respect to the Debentures.

                                  ARTICLE TWO

                        TITLE AND TERMS OF THE SECURITIES

         Section 201. Title of the Securities.

         The title of the Securities of the series established hereby is the
"3-1/2% Senior Exchangeable Debentures due 2031".

         Section 202. Amount and Denominations.

         The aggregate Original Principal Amount of the Debentures which may be
authenticated and delivered under the Indenture is initially limited to
$600,000,000, except for Debentures authenticated and delivered upon
registration of transfer of, or in exchange for, or in lieu of, other Debentures
pursuant to Section 304, 305, 306, 904 or 1107 of the Original Indenture;
provided, however, that the series of Securities established hereby may be
reopened, without the consent of the Holders of Outstanding Debentures, for
issuance of additional Debentures.

         Section 203. Registered Securities.

         The certificates for the Debentures shall be Registered Securities and
shall be in substantially the forms attached hereto as Exhibits A-1, A-2 or A-3,
and shall bear the legends as are inscribed thereon.

         Section 204. Stated Maturity; Changes to Original Principal Amount or
Adjusted Principal Amount.

         (a) The Stated Maturity of the principal of the Debentures shall be
January 15, 2031.

         (b) Not less than 30 Business Days prior to the Stated Maturity of the
principal of the Debentures, the Company shall issue a press release and provide
it to DTC for dissemination through the DTC broadcast facility, as to whether or
not the Company will deliver, or cause to be delivered, Reference Shares in
exchange for any Debentures submitted for exchange, in accordance with Section
209, from the date of such notice through 5:00 p.m., New York City time, on the
Trading Day next preceding such Stated Maturity. If Reference Shares are to be
delivered in connection with any such exchange, Debentures validly exchanged
during that period, in accordance with Section 209, will be exchanged for the
Reference Shares attributable to such Debentures, and the Company shall pay at
Stated Maturity to Holders that do not exchange their Debentures an amount, in
cash, determined in the same manner as the Redemption Price is determined in
Section 208(a)(ii) (substituting the term "Stated Maturity" for "Redemption
Date" therein), in full payment for such Debentures. If Reference Shares are not
to be delivered in connection with any such exchange, the exchange right set
forth in Section 209 will terminate as of the 30th Business Day prior to the
Stated Maturity of the principal of the Debentures and the Company shall pay at
Stated Maturity to Holders of Debentures an amount, in cash, determined in the
same manner as the Redemption Price is determined in Section 208(a)(i)(B)
(substituting the term "Stated Maturity" for "Redemption Date" therein), in full

                                       8
<PAGE>   11
payment for such Debentures. Any notice by the Company as to whether or not it
will deliver Reference Shares in exchange for Debentures pursuant to this
Section 204(b) shall be irrevocable.

         (c) The principal amount of each Debenture shall initially equal the
Original Principal Amount. Thereafter, the principal amount of each Debenture,
as of any date of determination, shall equal the Adjusted Principal Amount. In
calculating the Adjusted Principal Amount, (i) the value of any Extraordinary
Additional Distribution shall be subtracted as of the date it is distributed to
holders of the Debentures, and (ii) the amount of each Yield Adjustment shall be
subtracted on the Interest Payment Date to which such Yield Adjustment relates.
In no event will the Adjusted Principal Amount be less than zero. The Company
shall issue a press release upon the occurrence of each reduction to the
Adjusted Principal Amount, and provide it to DTC for dissemination through the
DTC broadcast facility.

         (d) At least five Business Days prior to the Stated Maturity of the
principal of Debentures, the Company shall deliver an Officers' Certificate to
the Trustee which: (i) sets forth the amount to be paid in accordance with
Section 204(b) at such Stated Maturity for each Debenture and for all Debentures
then Outstanding, (ii) sets forth a reasonably detailed calculation of such
amounts, and (iii) directs the Trustee to adjust its records accordingly and to
request the Depository to adjust its records accordingly. At or prior to 10:00
a.m., New York City time, on the date of Stated Maturity of the principal of the
Debentures, 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 1003 of the Original Indenture) an amount in cash
sufficient to pay, in accordance with Section 204(b), the amount due on all
Debentures that are Outstanding at 5:00 p.m., New York City time, on the date of
such Stated Maturity.

         (e) In the event of an acceleration of maturity of the Debentures
pursuant to Section 502 of the Original Indenture, there shall become
immediately due and payable an amount equal to the sum of (1) the greater of (a)
the Adjusted Principal Amount of the Debentures then Outstanding and (b) the
Current Market Value of the Reference Shares attributable to the Debentures, (2)
any accrued and unpaid interest on the Debentures and (3), subject to Section
211, any Final Period Distribution on the Debentures, determined as if (i) in
the case of an Event of Default specified in clause (8) or (9) of Section 501 of
the Original Indenture (as supplemented by Section 217(c) hereof), the date of
such Event of Default were the Stated Maturity of the principal of the
Debentures and (ii) in the case of any other Event of Default, the date of
declaration of acceleration were the Stated Maturity of the principal of the
Debentures.

         Section 205. Interest.

         (a) The Debentures shall bear interest from January 11, 2001 or from
the most recent Interest Payment Date to which interest has been paid or
provided for, payable semiannually on January 15 and July 15 of each year (each,
an "Interest Payment Date"), commencing July 15, 2001, to the Persons in whose
names the Debentures (or one or more Predecessor Securities) are registered at
the close of business on the January 1 or July 1 immediately preceding such
Interest Payment Date. Calculations of interest on each Debenture shall be based
on the Original Principal Amount, without regard to changes in the Adjusted
Principal Amount. Interest on the

                                       9
<PAGE>   12
Debentures shall be computed on the basis of a 360-day year of twelve 30-day
months. The amount of interest payable on the Debentures on the initial Interest
Payment Date shall be computed on the basis of six 30-day months and an
additional four days.

         (b) Interest on the Debentures will accrue at the rate of 3-1/2% per
annum until the principal thereof is paid or made available for payment;
provided, however, that such interest rate shall be subject to increase as
follows:

                  (i) the interest rate shall be increased ("Additional
         Interest") by one quarter of one percent (0.25%) per annum upon the
         occurrence of each Registration Default or Registration Suspension,
         which rate will increase by one quarter of one percent (0.25%) at the
         beginning of each 90-day period (or portion thereof) that such
         Additional Interest continues to accrue under any such circumstance,
         provided that the maximum amount of Additional Interest will in no
         event exceed one percent (1%) per annum. Immediately following the cure
         of a Registration Default, the accrual of Additional Interest with
         respect to such Registration Default will cease;

                  (ii) accrual of Additional Interest will cease and the
         interest rate will revert to the original rate, in the case of a
         Registration Default, upon the earlier to occur of (A) the cure of all
         Registration Defaults or (B) the date on which the Debentures are
         saleable pursuant to Rule 144(k) under the Securities Act or any
         successor provision; and in the case of a Registration Suspension, upon
         the Shelf Registration Statement once again becoming usable as
         contemplated under the Registration Rights Agreement;

                  (iii) Additional Interest shall accrue from and including the
         day following the applicable Event Date (as defined below), and shall
         be computed based on the actual number of days elapsed in each 90-day
         period; and

                  (iv) the Company shall deliver to the Trustee an Officers'
         Certificate within three Business Days after each and every date on
         which an event occurs in respect of which Additional Interest is
         required to be paid (an "Event Date").

         (c) At least five Business Days prior to each Interest Payment Date,
the Company shall deliver an Officers' Certificate to the Trustee setting forth:
(i) the amount of interest per Debenture due for that interest period, (ii) the
amount of any Excess Regular Cash Dividend Amount Distribution required to be
made under Section 206(b) and (iii) the total payment due for that period on all
Debentures outstanding.

         Section 206. Additional Distributions.

         (a) The Company shall distribute, or cause to be distributed, as an
Additional Distribution to each Holder of a Debenture, (i) any Excess Regular
Cash Dividend Amount received by a holder of the number of Reference Shares
attributable to a Debenture, and (ii) any Extraordinary Distribution received by
a holder of the number of Reference Shares attributable to a Debenture, or the
cash value thereof, in accordance with this Section 206.

         (b) In the case of any Excess Regular Cash Dividend Amount, the Company
shall pay, to the Holder of each Debenture, as an Excess Regular Cash Dividend
Amount Distribution,

                                       10
<PAGE>   13
the amount of the Excess Regular Cash Dividend Amount in any Interest Period on
the next Interest Payment Date to Holders of Debentures as of 5:00 p.m., New
York City time, on the Regular Record Date for such Interest Payment Date.

         (c) In the case of any Extraordinary Distribution, the Company shall
deliver, to the Holder of each Debenture, as an Extraordinary Additional
Distribution, all dividends and distributions, or the fair market value thereof
(determined in accordance with Section 206(d) or (e)), received by a holder of
the number of Reference Shares attributable to such Debenture in respect of such
Extraordinary Distribution. Any distribution pursuant to this subsection (c)
shall be made by the Company to Holders of Debentures as of a special record
date which shall be the 10th Business Day after the date of the payment of the
Extraordinary Distribution by the applicable Reference Company, and shall be
distributed to such Holders on the 10th Business Day following such special
record date.

         (d) If an Extraordinary Distribution consists of securities or units
that are Marketable Securities (other than securities which are, or become,
Reference Shares), such securities or units will be distributed by the Company
to Holders of the Debentures in accordance with Section 206(c); provided, that
the Company shall not distribute fractional securities or units. In lieu of
fractional securities or units, the Company shall pay the Holders of Debentures
an amount in cash equal to the Closing Price, as of the special record date, of
the security or unit to be distributed multiplied by such fractional interest.
For purposes of determining the existence of fractional interests, all
Debentures held by a Holder shall be considered together (no matter how many
separate certificates such Holder may have). In the event the Company is unable
to distribute any securities or units as part of an Extraordinary Additional
Distribution because any necessary qualifications or registrations of such
securities or units under applicable state or federal securities laws cannot be
obtained on a timely basis, the Company may instead deliver, in lieu of such
securities or units, cash based on the average of the Closing Prices of such
securities or units over the five Trading Days ending on the Trading Day next
preceding the distribution by the Company of such Extraordinary Additional
Distribution.

         (e) If an Extraordinary Distribution consists of cash, assets or
property other than securities or units that are Marketable Securities, the
Company shall pay to Holders of the Debentures an amount of cash equal to the
fair market value thereof; such fair market value to be determined as of the
date such Extraordinary Distribution is made or paid to holders of the
applicable Reference Shares. Such fair market value shall be equal to the amount
determined in good faith by the Board of Directors, unless the Board of
Directors determines in good faith that there is a substantial likelihood that
the aggregate fair market value will be in excess of $100,000,000, in which case
such fair market value shall be determined by a nationally recognized investment
banking or appraisal firm retained by the Company for this purpose. The fair
market value so determined shall be set forth in a Board Resolution or, in the
case of a determination by an investment banking or appraisal firm, an Officers'
Certificate.

         (f) At least five Business Days prior to the payment or delivery of an
Extraordinary Additional Distribution by the Company pursuant to Section 206(c),
the Company shall deliver to the Trustee a Board Resolution setting a special
record date for such Extraordinary Additional Distribution and an Officers'
Certificate setting forth: (i) the exact amount of Marketable Securities or cash
to be distributed on or with respect to the Reference Shares attributable to
each

                                       11
<PAGE>   14
Debenture, and (ii) the total amount of Marketable Securities or cash to be
distributed on or with respect to the Reference Shares attributable to all
Debentures that are Outstanding as of such special record date. If any
distribution relates to any assets or other property that is not publicly
traded, then at least five Business Days prior to such distribution, the Company
shall deliver to the Trustee: (i) a Board Resolution establishing the fair
market value of the assets or other property, unless such fair market value is
determined by a nationally recognized investment banking or appraisal firm, in
which case the Company shall deliver to the Trustee the report of such firm and
(ii) an Officers' Certificate setting forth (a) the exact amount of cash to be
distributed on or with respect to the Reference Shares attributable to each
Debenture and (b) the total amount of cash to be distributed on or with respect
to the Reference Shares attributable to all Debentures that are Outstanding as
of such special record date in respect of any assets or other property that is
not publicly traded. The Trustee is only responsible for distributing Marketable
Securities in the form of global book entry securities that are DTC eligible. At
or prior to 10:00 a.m., New York City time, on the date an Extraordinary
Additional Distribution is to be made pursuant to Section 206(c), the Company
shall (i) in the case of an Extraordinary Additional Distribution consisting of
cash, deposit with the Trustee or with a Paying Agent an amount of cash equal to
the Extraordinary Additional Distribution to be paid on such date and (ii) in
the case of an Extraordinary Additional Distribution consisting of Marketable
Securities, transfer by book-entry to the account of the Trustee or a Paying
Agent at DTC (or any successor Depository) the amount of Marketable Securities
to be distributed in such Extraordinary Additional Distribution on such date.
The Company shall act as its own Paying Agent for any Marketable Securities to
be delivered other than through book-entry. The Company shall issue a press
release setting forth the amount and composition, per Debenture, of any
Extraordinary Additional Distribution, and shall deliver such press release to
DTC for dissemination through the DTC broadcast facility.

         Section 207. Registration, Transfer and Exchange.

         The principal of and interest and Additional Distributions on the
Debentures shall be payable and the Debentures may be surrendered or presented
for payment, the Debentures may be surrendered for registration of transfer or
exchange, and notices and demands to or upon the Company in respect of the
Debentures and the Indenture may be served, at the office or agency of the
Company maintained for such purposes in The City of New York, State of New York
from time to time, and the Company hereby appoints the Trustee, acting through
its office or agency in The City of New York designated from time to time for
such purpose, as its agent for the foregoing purposes; provided, however, that
at the option of the Company payment of interest and Additional Distributions on
the Debentures may be made by check mailed to the address of the Persons
entitled thereto, as such addresses shall appear in the Security Register; and
provided, further, that (subject to Section 1002 of the Original Indenture) the
Company may at any time remove the Trustee as its office or agency in The City
of New York designated for the foregoing purposes and may from time to time
designate one or more other offices or agencies for the foregoing purposes and
may from time to time rescind such designations. Notwithstanding the foregoing,
a Holder of $10 million or more in aggregate Original Principal Amount of
Debentures on a Regular Record Date shall be entitled to receive interest
payments on the next succeeding Interest Payment Date, other than an Interest
Payment Date that is also the date of Maturity, by wire transfer of immediately
available funds if appropriate wire transfer instructions have been received in
writing by the Trustee not less than 15 calendar days prior to

                                       12
<PAGE>   15
the applicable Interest Payment Date. Any wire transfer instructions received by
the Trustee will remain in effect until revoked by the Holder.

         (a) Rule 144A Debenture to Temporary Regulation S Debenture. Prior to
the expiration of the "40-day restricted period" (within the meaning of Rule
903(c)(3) of Regulation S) (the "Restricted Period"), if a holder of a
beneficial interest in a Rule 144A Debenture deposited with the Depository
wishes at any time to exchange all or a portion of its interest in such Rule
144A Debenture for an interest in the Temporary Regulation S Debenture, or to
transfer all or a portion of its interest in such Rule 144A Debenture to a
Person who wishes to take delivery thereof in the form of an interest in such
Temporary Regulation S Debenture, such holder may, subject to the rules and
procedures of the Depository and to the requirements set forth in the following
sentence, exchange or cause the exchange or transfer or cause the transfer of
such interest for an equivalent beneficial interest in such Temporary Regulation
S Debenture. Upon receipt by the Trustee, as transfer agent, at its principal
corporate trust office in The City of New York of (1) instructions given in
accordance with the Depository's procedures from an agent member directing the
Trustee to credit or cause to be credited a beneficial interest in the Temporary
Regulation S Debenture in an amount equal to the beneficial interest in the Rule
144A Debenture to be exchanged or transferred, (2) a written order given in
accordance with the Depository's procedures containing information regarding the
account at Euroclear Bank, as operator of the Euroclear System ("Euroclear"), or
Clearstream Banking, societe anonyme (formerly Cedelbank) ("Clearstream,
Luxembourg") to be credited with such increase and the name of such account and
(3) a certificate substantially in the form of Exhibit B hereto given by the
holder of such beneficial interest, the Trustee, as transfer agent, shall
instruct the Depository, its nominee, or the custodian for the Depository, as
the case may be, to reduce or reflect on its records a reduction of the Rule
144A Debenture by the aggregate principal amount of the beneficial interest in
such Rule 144A Debenture to be so exchanged or transferred and the Trustee, as
transfer agent, shall instruct the Depository, its nominee, or the custodian for
the Depository, as the case may be, concurrently with such reduction, to
increase or reflect on its records an increase of the principal amount of such
Temporary Regulation S Debenture by the aggregate principal amount of the
beneficial interest in such Rule 144A Debenture to be so exchanged or
transferred, and to credit or cause to be credited to the account of the Person
specified in such instructions (who shall be the agent member of Euroclear or
Clearstream, Luxembourg, or both, as the case may be) a beneficial interest in
such Temporary Regulation S Debenture equal to the reduction in the principal
amount of such Rule 144A Debenture.

         (b) Rule 144A Debenture to Permanent Regulation S Debenture. After the
expiration of the Restricted Period, if a holder of a beneficial interest in the
Rule 144A Debenture deposited with the Depository wishes at any time to exchange
all or a portion of its interest in such Rule 144A Debenture for an interest in
the Permanent Regulation S Debenture, or to transfer all or a portion of its
interest in such Rule 144A Debenture to a Person who wishes to take delivery
thereof in the form of an interest in such Permanent Regulation S Debenture,
such holder may, subject to the rules and procedures of the Depository and to
the requirements set forth in the following sentence, exchange or cause the
exchange or transfer or cause the transfer of such interest for an equivalent
beneficial interest in such Permanent Regulation S Debenture. Upon receipt by
the Trustee, as transfer agent, at its principal corporate trust office in The
City of New York of (1) instructions given in accordance with the Depository's
procedures from an agent member directing the Trustee to credit or cause to be
credited a beneficial interest in the

                                       13
<PAGE>   16
Permanent Regulation S Debenture in an amount equal to the beneficial interest
in the Rule 144A Debenture to be exchanged or transferred, (2) a written order
given in accordance with the Depository's procedures containing information
regarding the Euroclear or Clearstream, Luxembourg account to be credited with
such increase and (3) a certificate substantially in the form of Exhibit C
hereto given by the holder of such beneficial interest, the Trustee, as transfer
agent, shall instruct the Depository, its nominee, or the custodian for the
Depository, as the case may be, to reduce or reflect on its records a reduction
of the Rule 144A Debenture by the aggregate principal amount of the beneficial
interest in such Rule 144A Debenture to be so exchanged or transferred and the
Trustee, as transfer agent, shall instruct the Depository, its nominee, or the
custodian for the Depository, as the case may be, concurrently with such
reduction, to increase or reflect on its records an increase of the principal
amount of such Permanent Regulation S Debenture by the aggregate principal
amount of the beneficial interest in such Rule 144A Debenture to be so exchanged
or transferred, and to credit or cause to be credited to the account of the
Person specified in such instructions (who shall be the agent member of
Euroclear or Clearstream, Luxembourg, or both, as the case may be) a beneficial
interest in such Permanent Regulation S Debenture equal to the reduction in the
principal amount of such Rule 144A Debenture.

         (c) Regulation S Security to Rule 144A Debenture. If a holder of a
beneficial interest in the Temporary Regulation S Debenture or the Permanent
Regulation S Debenture which is deposited with the Depository wishes at any time
to exchange its interest for an interest in the Rule 144A Debenture, or to
transfer its interest in such Temporary Regulation S Debenture or Permanent
Regulation S Debenture to a Person who wishes to take delivery thereof in the
form of an interest in such Rule 144A Debenture, such holder may, subject to the
rules and procedures of Euroclear or Clearstream, Luxembourg and the Depository,
as the case may be, and to the requirements set forth in the following sentence,
exchange or cause the exchange or transfer or cause the transfer of such
interest for an equivalent beneficial interest in such Rule 144A Debenture. Upon
receipt by the Trustee, as transfer agent, at its principal corporate trust
office in The City of New York of (1) instructions from Euroclear or
Clearstream, Luxembourg or the Depository, as the case may be, directing the
Trustee, as transfer agent, to credit or cause to be credited a beneficial
interest in the Rule 144A Debenture in an amount equal to the beneficial
interest in the Temporary Regulation S Debenture or the Permanent Regulation S
Debenture to be exchanged or transferred, such instructions to contain
information regarding the agent member's account with the Depository to be
credited with such increase, and (2) with respect to an exchange or transfer of
an interest in the Temporary Regulation S Debenture (but not the Permanent
Regulation S Debenture) for an interest in the Rule 144A Debenture, a
certificate substantially in the form of Exhibit D hereto given by the holder of
such beneficial interest, the Trustee, as transfer agent, shall instruct the
Depository, its nominee, or the custodian for the Depository, as the case may
be, to reduce or reflect on its records a reduction of the Temporary Regulation
S Debenture or such Permanent Regulation S Debenture, as the case may be, by the
aggregate principal amount of the beneficial interest in such Temporary
Regulation S Debenture or such Permanent Regulation S Debenture to be exchanged
or transferred, and the Trustee, as transfer agent, shall instruct the
Depository, its nominee, or the custodian for the Depository, as the case may
be, concurrently with such reduction, to increase or reflect on its records an
increase of the principal amount of such Rule 144A Debenture by the aggregate
principal amount of the beneficial interest in such Permanent Regulation S
Debenture or such Temporary Regulation S Debenture, as the case may be, to be so
exchanged or transferred, and to credit or

                                       14
<PAGE>   17
cause to be credited to the account of the Person specified in such instructions
a beneficial interest in such Rule 144A Debenture equal to the reduction in the
principal amount of such Permanent Regulation S Debenture or such Temporary
Regulation S Debenture, as the case may be.

         (d) Temporary Regulation S Debenture to Permanent Regulation S
Debenture. After the expiration of the Restricted Period, interests in a
Temporary Regulation S Debenture as to which the Trustee has received from
Euroclear or Clearstream, Luxembourg, as the case may be, a certificate
substantially in the form of Exhibit E hereto to the effect that Euroclear or
Clearstream, Luxembourg, as applicable, has received a certificate substantially
in the form of Exhibit F hereto from the holder of a beneficial interest in such
Temporary Regulation S Debenture, will be exchanged, on and after the Restricted
Period, for interests in the Permanent Regulation S Debenture. The Trustee shall
effect such exchange by delivering to the Depository for credit to the
respective accounts of the holders of Debentures represented by a beneficial
interest in the Temporary Regulation S Global Debenture, a duly executed and
authenticated Permanent Regulation S Debenture, representing the principal
amount of interests in the Temporary Regulation S Debenture initially exchanged
for interests in the Permanent Regulation S Debenture. The delivery to the
Trustee by Euroclear or Clearstream, Luxembourg of the certificate or
certificates referred to above may be relied upon by the Company and the Trustee
as conclusive evidence that the certificate or certificates referred to therein
has or have been delivered to Euroclear or Clearstream, Luxembourg pursuant to
the terms of this Fifth Supplemental Indenture and the Temporary Regulation S
Debenture. Upon any exchange of interests in a Temporary Regulation S Debenture
for interests in a Permanent Regulation S Debenture, the Trustee shall endorse
the Temporary Regulation S Debenture to reflect the reduction in the principal
amount represented thereby by the amount so exchanged and shall endorse the
Permanent Regulation S Debenture to reflect the corresponding increase in the
amount represented thereby. Until so exchanged in full and except as provided
therein, the Temporary Regulation S Debenture, and the Debentures evidenced
thereby, shall in all respects be entitled to the same benefits under the
Indenture as the Permanent Regulation S Debenture and the Rule 144A Debenture
authenticated and delivered hereunder.

         Section 208. Redemption of the Debentures.

         (a) Optional Redemption. The Debentures will be redeemable at the
option of the Company, in whole or in part (provided that immediately after any
partial redemption at least $100,000,000 Original Principal Amount of Debentures
would remain outstanding) at any time or from time to time after January 15,
2006, on at least 30 Business Days (but not more than 60 days) prior notice to
Holders of the Debentures. In the notice of redemption, the Company shall
specify its irrevocable election of one of the following options:

                  (i) to terminate Holders' right to exchange, in accordance
         with Section 209, Debentures called for redemption (but not affecting
         the exchange rights of Holders of any Debentures not called for
         redemption), in which case (A) no further exchange of such Debentures
         called for redemption pursuant to Section 209 will be permitted on or
         after the 30th Business Day preceding the Redemption Date and (B) on
         the Redemption Date, the Company shall pay Holders, for each Debenture
         to be redeemed, a Redemption Price, in cash, equal to the sum of (1)
         the greater of (a) the Adjusted Principal Amount of such

                                       15
<PAGE>   18
         Debenture as of the Redemption Date and (b) 100% of the Current Market
         Value of the Reference Shares attributable to such Debenture, (2) any
         accrued and unpaid interest on such Debenture to the Redemption Date
         and (3), subject to Section 211, any Final Period Distribution on such
         Debenture; or

                  (ii) to exchange Debentures surrendered at the option of
         Holders in accordance with Section 209, for Reference Shares until 5:00
         p.m., New York City time, on the Trading Day next preceding the
         Redemption Date, in which case on the Redemption Date the Company shall
         pay Holders who do not elect to exchange Debentures for Reference
         Shares in accordance with Section 209(c), for each Debenture to be
         redeemed, a Redemption Price, in cash, equal to the sum of (1) the
         Adjusted Principal Amount of such Debenture at the Redemption Date, (2)
         any accrued and unpaid interest on such Debenture to the Redemption
         Date and (3), subject to Section 211, any Final Period Distribution on
         such Debenture.

         (b) Tax Event Redemption. If at any time on or prior to May 15, 2001, a
Tax Event shall have occurred, the Company shall have the right, exercisable by
giving notice of such redemption to the Trustee within 180 days after the Tax
Event, to give notice to Holders of the Debentures of a Tax Event Redemption,
which shall occur not less than twenty-five (25) Business Days following the
giving of such notice. Any Tax Event Redemption must apply to all Outstanding
Debentures. On the Redemption Date specified in the notice of redemption to
Holders of the Debentures, the Company shall pay Holders for each Debenture a
Redemption Price, in cash, equal to the sum of (1) the greater of (A) 102% of
the Adjusted Principal Amount of such Debenture and (B) 100% of the Current
Market Value of the Reference Shares attributable to such Debenture, (2) any
accrued and unpaid interest on such Debenture to the Redemption Date and (3),
subject to Section 211, any Final Period Distribution on such Debenture. The
Holders' right to exchange Debentures pursuant to Section 209 shall terminate on
the later of the date notice of a Tax Event Redemption is given or the 25th
Business Day prior to the Redemption Date.

         (c) Notices. In case of any redemption, the Company shall deliver an
Officers' Certificate to the Trustee not less than five Business Days prior to
the Redemption Date which sets forth (i) the Redemption Price to be paid for
each Debenture called for redemption on such Redemption Date and (ii) the
aggregate amount payable for all Debentures called for redemption on such
Redemption Date.

         (d) Interest Accrual to Cease. Once notice of redemption has been given
and funds are irrevocably deposited with the Trustee, interest on the Debentures
will cease to accrue on and after the Redemption Date and all rights of the
Holders of the Debentures called for redemption will cease, except for the right
of Holders to receive the Redemption Price (but without interest on such
Redemption Price) and any right to receive payment pursuant to Section 211.

         (e) Payment Failure. In the event that the Company fails to pay any
amount due on redemption of the Debentures on a Redemption Date, interest on the
Debentures called for redemption shall continue to accrue at an annual rate of
3-1/2% of the Original Principal Amount thereof from the date originally set for
redemption to the actual date of payment, and such actual date of payment shall
be deemed to be the Redemption Date for purposes of calculating the

                                       16
<PAGE>   19
amount to be paid to the Holders of Debentures on redemption, except that the
amount of the Final Period Distribution shall be determined as of the date
originally set for redemption.

         (f) Company Notice. Section 1002 of the Original Indenture is hereby
deleted, solely with respect to the Debentures, and in lieu thereof the
following shall be applicable to the Debentures:

                  "The election of the Company to optionally redeem any
         Debentures shall be evidenced by or pursuant to a Board Resolution. In
         the case of any optional redemption by the Company that involves less
         than all of the Debentures, the Company shall, at least 60 days prior
         to the Redemption Date fixed by the Company (unless a shorter period
         shall be acceptable to the Trustee), notify the Trustee of such
         Redemption Date and of the Original Principal Amount of Debentures to
         be redeemed."

         Section 209. Exchange of the Debentures.

         (a) Each Debenture will be exchangeable at the option of the Holder at
any time (except as otherwise provided in subsection (f) below) for the Exchange
Market Value of the Reference Shares attributable to that Debenture. The number
of Reference Shares attributable to each Debenture shall initially be 36.8189,
subject to adjustment as a result of any Reference Share Proportionate Reduction
or any other adjustment contemplated by the definition of "Reference Shares."

         (b) The Company may, at its option, (i) pay 100% of the Exchange Market
Value of the Reference Shares attributable to each Debenture, in cash; (ii)
deliver the Reference Shares attributable to such Debenture in payment of such
Exchange Market Value; or (iii) deliver a combination of Reference Shares and
cash. Such payment or delivery will be made as promptly as practicable, but in
any event within ten Trading Days after the date of determination of the
Exchange Market Value. The Company shall notify the Exchange Agent of its
election to pay cash or deliver Reference Shares, or a combination of the
foregoing, which shall be irrevocable, by no later than 9:30 a.m., New York City
time, on the Trading Day next following the applicable Exchange Date. The
Exchange Agent shall notify an exchanging Holder of the Company's election under
this Section 209(b) prior to 10:00 a.m., New York City time, on the next Trading
Day after the Exchange Date.

         (c) To exchange a Debenture a Holder must (a) in the case of a
Debenture held through the Depository, surrender such Debenture for exchange
through book-entry transfer into the account of the Exchange Agent, transmit an
agent's message requesting such exchange and comply with such other procedures
of the Depository as may be applicable in the case of an exchange and (b) in the
case of a Debenture held in certificated form, (i) complete and manually sign
the Notice of Exchange attached to the Debenture (or complete and sign a
facsimile of the Notice of Exchange) and deliver such Notice of Exchange to the
Exchange Agent, (ii) surrender the Debenture to the Exchange Agent, (iii)
furnish appropriate endorsements and transfer documents, if required by the
Exchange Agent, the Company or the Trustee and (iv) pay any transfer or similar
tax, if required. An exchange shall be deemed to have been effected at 5:00
p.m., New York City time, on the Exchange Date. The delivery of a Notice of
Exchange or, in the case of book-entry, an agent's message requesting exchange,
shall be irrevocable. A Holder

                                       17
<PAGE>   20
may exchange a portion of its Debentures only if the portion is $1,000 Original
Principal Amount or an integral multiple thereof. Following the Exchange Date
for an exchange of Debentures, all rights of the Holder with respect to such
Debentures shall cease, except for the right of such Holder to receive 100% of
the Exchange Market Value of the Reference Shares attributable to such
Debentures.

         (d) By 10:00 a.m., New York City time, on each Trading Day following
receipt by the Exchange Agent of notification from DTC that DTC has received an
agent's message from a DTC participant electing to exercise its exchange option
with respect to its Debentures, and delivery of such Debentures into the
Exchange Agent's DTC participant account, or following receipt of a complete
manually signed Notice of Exchange and receipt of certificated Debentures from a
Holder, the Exchange Agent shall notify the Company of the principal amount of
Debentures which has been tendered. When the Exchange Market Value has been
determined, the Company shall deliver an Officers' Certificate to the Trustee
setting forth the exact amount to be paid or the amount of Reference Shares to
be delivered to the tendering Holder and shall deposit such amount with the
Exchange Agent (except that if the Company elects to deliver Reference Shares in
certificated form, the Company shall act as its own Paying Agent as to such
shares). Upon receipt of such payment or delivery from the Company, the Exchange
Agent shall pay DTC as soon as practicable or, in the cases of Debentures that
are held in certificated form, as directed by the tendering Holder. Where the
Company acts as its own Paying Agent with respect to certificated Reference
Shares, it shall deliver them (i) as directed by the relevant participants of
the Depositary, as identified by the Depositary, or (ii) to or at the direction
of tendering Holders of Debentures.

         (e) In the case of any exchange made during the period from (but
excluding) a Regular Record Date for any Interest Payment Date to (but
excluding) such Interest Payment Date, the Holder shall tender funds equal to
the interest and any Additional Distribution payable on such Interest Payment
Date.

         (f) The right to exchange Debentures pursuant to this Section 209 shall
terminate at 5:00 p.m., New York City time, (i) in the case of Stated Maturity
of the principal amount of the Debentures, on the Trading Day immediately
preceding such Stated Maturity and (ii) in the case of an optional redemption,
on the Trading Day immediately preceding the Redemption Date. A Holder's right
to exchange Debentures under this Section 209 shall further be subject to
termination by the Company (i) in connection with the payment of the Debentures
at Stated Maturity, during the period set forth in the penultimate sentence of
Section 204(b), (ii) in connection with optional redemption, during the period
set forth in clause (i) of Section 208(a), provided, that any such termination
shall only apply to Debentures that have been called for redemption and, (iii)
in connection with a Tax Event Redemption, during the period set forth in
Section 208(b).

         (g) If more than $1,000,000 aggregate Original Principal Amount of
Debentures are tendered for exchange on any given date, the Company shall give
notice of such event to the Trustee and the Trustee shall give notice thereof to
DTC for distribution through its broadcast facility.


                                       18
<PAGE>   21
         Section 210. Distributions of Reference Shares or Other Securities.

         (a) The Company will pay any and all documentary, stamp, transfer or
similar taxes that may be payable in respect of the transfer and delivery of
Reference Shares or in connection with an Extraordinary Additional Distribution
pursuant hereto; provided, however, that the Company shall not be required to
pay any such tax which may be payable in respect of any transfer involved in
delivery of such property to a name other than that in which the Debentures were
registered, and no such transfer or delivery shall be made unless and until the
Person requesting such transfer 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.

         (b) The Company hereby warrants that upon delivery of any Reference
Shares or any securities in connection with any Extraordinary Additional
Distribution pursuant to this Supplemental Indenture, the Holder of a Debenture
shall receive all rights held by the Company in the securities to be delivered,
free and clear of any and all liens, claims, charges and encumbrances, other
than any liens, claims, charges and encumbrances which may have been placed
thereon by the prior owner thereof prior to the time acquired by the Company. In
addition, the Company further warrants that any securities to be delivered
hereunder shall be free of any transfer restrictions under federal or state
securities laws (other than such as are solely attributable to any Holder's
status as an affiliate of the issuer of such securities).

         Section 211. Balance of Final Period Distribution Payment.

         (a) In the case of a Final Period Distribution within the meaning of
clause (b) of the definition of "Final Period Distribution," the Company shall
pay such Final Period Distribution to the Holders of Debentures that have been
repaid in accordance with the first sentence of Section 204(b) or redeemed in
accordance with Section 208(a) or (b) as of a special record date which shall be
the 10th Business Day after the date of the payment of the relevant
Extraordinary Distribution by the applicable Reference Company; and such payment
shall be distributed on the 10th Business Day following such special record
date. The Company shall give notice regarding such distribution to the Trustee
in accordance with the provisions of Section 206(f).

         (b) In the event that the applicable Reference Company fails to make
the Extraordinary Distribution referred to in subsection (a) above at the time
or in the amount expected, the Company shall pursue any claim it has against
such Reference Company, whether as a securityholder or otherwise, on behalf of
the Holders of Debentures. Reasonable costs of such actions by the Company may
be deducted from the amount of any Extraordinary Distribution before any
distribution is made to Holders of Debentures pursuant to Section 211(a).

         Section 212. Denominations.

         The Debentures shall be issued in denominations of $1,000 and integral
multiples in excess thereof.

         Section 213. Applicability of Certain Original Indenture Provisions.

         Section 402 of the Original Indenture, relating to defeasance and
covenant defeasance, shall not be applicable to the Debentures.


                                       19
<PAGE>   22
         Section 214. Security Registrar and Paying Agent.

         The Trustee shall be the initial Paying Agent and initial transfer
agent for the Debentures (subject to the Company's right (subject to Section
1002 of the Original Indenture) to remove the Trustee as such Paying Agent
and/or transfer agent and, from time to time, to designate one or more
co-registrars and one or more other Paying Agents and transfer agents and to
rescind from time to time any such designations), and The City of New York is
designated as a Place of Payment for the Debentures.

         Section 215. Global Debentures.

         (a) The Debentures shall be issued in the form of one or more temporary
or global Debentures. The initial Depository for the global Debentures shall be
DTC, and the depositary arrangements shall be those employed by whoever shall be
the Depositary with respect to the Debentures from time to time.

         (b) Rule 144A Debentures. Debentures initially offered and sold in
reliance on Rule 144A to Qualified Institutional Buyers (as such term is defined
in Rule 144A) shall be issued in the form of permanent global Debentures in
definitive fully registered form without interest coupons, substantially in the
form of Exhibit A-1 (a "Rule 144A Debenture"). Each Rule 144A Debenture shall be
deposited on behalf of the purchasers of the Debentures represented thereby with
the custodian for the Depositary, and registered in the name of a nominee of the
Depositary, duly executed by the Company and authenticated by the Trustee as
provided in the Original Indenture. The aggregate principal amount of a Rule
144A Debenture may from time to time be increased or decreased by adjustments
made on the records of the custodian for the Depositary or the Depositary or its
nominee, as the case may be.

         (c) Temporary Regulation S Debentures; Permanent Regulation S
Debentures. Debentures initially offered and sold in reliance on Regulation S
shall be issued in the form of temporary global Debentures in definitive fully
registered form without interest coupons, substantially in the form of Exhibit
A-2 (a "Temporary Regulation S Debenture"). Each Temporary Regulation S
Debenture shall be deposited on behalf of the purchasers of the Debentures
represented thereby with the custodian for the Depositary, and registered in the
name of a nominee of the Depositary, duly executed by the Company and
authenticated by the Trustee as provided herein, for credit to their respective
accounts (or to such other accounts as they may direct) at Euroclear or
Clearstream, Luxembourg. After the expiration of the Restricted Period, each
Temporary Regulation S Debenture will be exchanged for a permanent global
Debenture, substantially in the form of Exhibit A-3 (a "Permanent Regulation S
Debenture"). Until the expiration of the Restricted Period, interests in a
Temporary Regulation S Debenture may only be held by agent members of Euroclear
and Clearstream, Luxembourg. During the Restricted Period, interests in a
Temporary Regulation S Debenture may be exchanged for interests in a Rule 144A
Debenture. The aggregate principal amount of a Temporary Regulation S Debenture
and a Permanent Regulation S Debenture may from time to time be increased or
decreased by adjustments made on the records of the custodian for the Depositary
or the Depositary or its nominee, as the case may be, as provided herein.


                                       20
<PAGE>   23
         The provisions of the "Operating Procedures of the Euroclear System"
and the "Terms and Conditions Governing Use of Euroclear" and the "Management
Regulations" and "Instructions to Participants" of Clearstream, Luxembourg,
respectively, shall be applicable to any global Debenture insofar as interests
in such global Debenture are held by the agent members of Euroclear or
Clearstream, Luxembourg. Account holders or participants in Euroclear and
Clearstream, Luxembourg shall have no rights under the Indenture with respect to
such global Debenture, and the Depositary or its nominee may be treated by the
Company, the Trustee, and any agent of the Company or the Trustee as the owner
of such global Debenture for all purposes whatsoever. 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 impair, as between
DTC and its agent members, the operation of customary practices governing the
exercise of the rights of a holder of any Debenture.

         (d) The Rule 144A Debentures, the Temporary Regulation S Debentures and
the Permanent Regulation S Debentures will be exchangeable for certificated
Debentures of like tenor and terms and of differing authorized denominations
aggregating a like principal amount, only if (i) the Depository notifies the
Company that it is unwilling or unable to continue as Depository for the Rule
144A Debentures, the Temporary Regulation S Debentures and the Permanent
Regulation S Debentures, (ii) the Depository ceases to be a clearing agency
under the Securities Exchange Act, (iii) the Company in its sole discretion
determines that the Rule 144A Debentures, the Temporary Regulation S Debentures
and the Permanent Regulation S Debentures shall be exchangeable for certificated
Debentures or (iv) there shall have occurred and be continuing an Event of
Default under the Indenture with respect to the Debentures. Upon such exchange,
the certificated Debentures shall be registered in the names of the beneficial
owners of the Rule 144A Debentures, the Temporary Regulation S Debentures and
the Permanent Regulation S Debentures, which they have replaced; such names
shall be provided to the Trustee by the relevant participants of the Depository,
as identified by the Depository.

         Section 216. Sinking Fund.

         The Debentures shall not be subject to any sinking fund or similar
provision and shall not be redeemable at the option of the holder thereof.

         Section 217. Amendments to Certain Sections of the Original Indenture.

         (a) The amendments to the Original Indenture contained in this Section
217 shall apply only to the series of Debentures established pursuant to this
Fifth Supplemental Indenture.

         (b) Clause (1) of Section 501 of the Original Indenture is hereby
amended by adding the words "or distributions" following the word "interest" on
the first and third lines.

         (c) A new clause (3) is hereby added to Section 501 of the Original
Indenture, to read as follows, and existing clauses (3) through (9) are
renumbered accordingly and all references in the Original Indenture to existing
clauses (3) through (9) are renumbered accordingly:


                                       21
<PAGE>   24
                  (3) failure of the Company to comply with its obligations to
         deliver cash or Reference Shares in exchange for Debentures pursuant to
         Section 209 of this Fifth Supplemental Indenture.

         (d) Clauses (1) and (2) of the second paragraph of Section 502 of the
Original Indenture are hereby amended by adding the words "and distributions"
following the word "interest" in the second line of each such clause.

         (e) Clause (1) of Section 902 of the Original Indenture is hereby
amended by adding the words "or distributions" following the word "interest" on
the second line.

         (f) Section 902 of the Original Indenture is hereby further amended by
adding a new clause (5), to read as follows:

                  (5) reduce the amount of cash or Reference Shares deliverable
         upon exchange of the Debentures.

         (g) Unless the context otherwise requires, all references to payment of
principal in the Original Indenture shall include the payment of the Maturity
Repayment Amount, and all references to payment of interest shall include
Additional Distributions.

                                 ARTICLE THREE

                            MISCELLANEOUS PROVISIONS

         The Trustee makes no undertaking or representations in respect of, and
shall not be responsible in any manner whatsoever for and in respect of, the
validity or sufficiency of this Fifth Supplemental Indenture or the proper
authorization or the due execution hereof by the Company or for or in respect of
the recitals and statements contained herein, all of which recitals and
statements are made solely by the Company.

         Except as expressly amended hereby, the Original Indenture shall
continue in full force and effect in accordance with the provisions thereof and
the Original Indenture is in all respects hereby ratified and confirmed. This
Fifth Supplemental Indenture and all its provisions shall be deemed a part of
the Original Indenture in the manner and to the extent herein and therein
provided.

         This Fifth Supplemental Indenture shall be governed by, and construed
in accordance with, the laws of the State of New York, without regard to
conflicts of laws principles thereof.

         This Fifth Supplemental Indenture 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.




                                       22
<PAGE>   25
         IN WITNESS WHEREOF, the parties hereto have caused this Fifth
Supplemental Indenture to be duly executed as of the day and year first above
written.

                                    LIBERTY MEDIA CORPORATION

                                    By:  _______________________________________
                                         Name:  Elizabeth M. Markowski
                                         Title: Senior Vice President

                                    THE BANK OF NEW YORK, as Trustee



                                    By:  _______________________________________
                                         Name:  Walter Gitlin
                                         Title: Vice President




                                       23
<PAGE>   26
                                                                     EXHIBIT A-1



                               Rule 144A Debenture




                                      A-1-1
<PAGE>   27
                                                                     EXHIBIT A-2



                        Temporary Regulation S Debenture




                                      A-2-1
<PAGE>   28
                                                                     EXHIBIT A-3



                        Permanent Regulation S Debenture




                                      A-3-1
<PAGE>   29
                                                                       EXHIBIT B



                          FORM OF TRANSFER CERTIFICATE
                FOR EXCHANGE OR TRANSFER FROM RULE 144A DEBENTURE
                       TO TEMPORARY REGULATION S DEBENTURE



The Bank of New York
101 Barclay Street
Floor 21 West
New York, New York  10286

                  Re:      Liberty Media Corporation
                           $550,000,000 3-1/2% Senior Exchangeable Debentures
                           due 2031 (the "Debentures")


         Reference is hereby made to the Indenture dated as of July 7, 1999,
between THE BANK OF NEW YORK (the "Trustee") and LIBERTY MEDIA CORPORATION (the
"Company") (as supplemented by the Fifth Supplemental Indenture, dated as of
January 11, 2001, between the Company and the Trustee, the "Indenture").
Capitalized terms not defined in this Certificate shall have the meanings given
to them in the Indenture.

         This Certificate relates to ______________ Original Principal Amount of
Debentures represented by a beneficial interest in the Rule 144A Debenture
(CUSIP No.____) held through the Depository by or on behalf of _____________ as
beneficial owner (the "Transferor"). The Transferor has requested an exchange or
transfer of its beneficial interest for an interest in the Temporary Regulation
S Debenture (CUSIP (CINS) No._____) to be held with [Euroclear] [Clearstream,
Luxembourg] (ISIN Code _____) (Common Code _____) through the Depository.

         In connection with such request and in respect of such Debentures, the
Transferor does hereby certify that such exchange or transfer has been effected
in accordance with the transfer restrictions set forth in the Debentures and
pursuant to and in accordance with Rule 903 or Rule 904 (as applicable) of
Regulation S under the Securities Act, and accordingly the Transferor does
hereby certify that:

         (1)      the offer of the Debentures was not made to a person in the
                  United States;

         (2)      either:  (A)      at the time the buy order was originated,
                                    the transferee was outside the United States
                                    or the Transferor and any person acting on
                                    its behalf reasonably believed that the
                                    transferee was outside the United States, or

                           (B)      the transaction was executed in, on or
                                    through the facilities of a designated
                                    offshore securities market and neither the
                                    Transferor nor any person acting on its
                                    behalf knows that the transaction was
                                    prearranged with a buyer in the United
                                    States;


                                      B-1
<PAGE>   30
         (3)      no directed selling efforts have been made in contravention of
                  the requirements of Rule 903(b) or 904(b) of Regulation S, as
                  applicable;

         (4)      the transaction is not part of a plan or scheme to evade the
                  registration requirements of the Securities Act; and

         (5)      upon completion of the transaction, the beneficial interest
                  being transferred as described above is to be held with the
                  Depository through Euroclear or Clearstream, Luxembourg or
                  both (Common Code ____ (ISIN Code _____)).

         This Certificate and the statements contained herein are made for your
benefit and the benefit of the Company and the initial purchaser of the
Debentures being exchanged or transferred. Terms used in this Certificate and
not otherwise defined in the Indenture have the meanings set forth in Regulation
S under the Securities Act.

                                        [Insert Name of Transferor]



                                        By:_____________________________________
                                           Name:
                                           Title:


Dated:   _________________________

cc:      Liberty Media Corporation




                                      B-2
<PAGE>   31
                                                                       EXHIBIT C



                    FORM OF TRANSFER CERTIFICATE FOR TRANSFER
                      OR EXCHANGE FROM RULE 144A DEBENTURE
                       TO PERMANENT REGULATION S DEBENTURE

The Bank of New York
101 Barclay Street
Floor 21 West
New York, New York  10286

                  Re:      Liberty Media Corporation
                           $550,000,000 3-1/2% Senior Exchangeable Debentures
                           due 2031 (the "Debentures")

         Reference is hereby made to the Indenture dated as of July 7, 1999,
between THE BANK OF NEW YORK (the "Trustee") and LIBERTY MEDIA CORPORATION (the
"Company") (as supplemented by the Fifth Supplemental Indenture, dated as of
January 11, 2001, between the Company and the Trustee, the "Indenture").
Capitalized terms not defined in this Certificate shall have the meanings given
to them in the Indenture.

         This Certificate relates to ______________ Original Principal Amount of
Debentures represented by a beneficial interest in the Rule 144A Debenture
(CUSIP No.____) held through the Depository by or on behalf of ____________ as
beneficial owner (the "Transferor"). The Transferor has requested an exchange or
transfer of its interest for an interest in the Permanent Regulation S Debenture
(CUSIP (CINS) No. [____]) to be held by [Euroclear][Clearstream, Luxembourg]
(ISIN Code _______) (Common Code) through the Depositary.

         In connection with such request and in respect of such Debentures, the
Transferor does hereby certify that such exchange or transfer has been effected
in accordance with the transfer restrictions set forth in the Debentures and
that, with respect to transfers made in reliance on Regulation S under the
Securities Act:

         (1)      the offer of the Debentures was not made to a person in the
                  United States;

         (2)      either:  (A)      at the time the buy order was originated,
                                    the transferee was outside the United States
                                    or the Transferor and any person acting on
                                    its behalf reasonably believed that the
                                    transferee was outside the United States, or

                           (B)      the transaction was executed in, on or
                                    through the facilities of, a designated
                                    offshore securities market and neither the
                                    Transferor nor any person acting on its
                                    behalf knows that the transaction was
                                    pre-arranged with a buyer in the United
                                    States;

         (3)      no directed selling efforts have been made in contravention of
                  the requirements of Rule 903(b) or 904(b) of Regulation S, as
                  applicable; and




                                      C-1
<PAGE>   32
         (4)      the transaction is not part of a plan or scheme to evade the
                  registration requirements of the Securities Act.

         This Certificate and the statements contained herein are made for your
benefit and the benefit of the Company and the initial purchaser of the
Debentures being exchanged or transferred. Terms used in this Certificate and
not otherwise defined in the Indenture have the meanings set forth in Regulation
S under the Securities Act.

                                        [Insert Name of Transferor]



                                        By:_____________________________________
                                           Name:
                                           Title:


Dated:   _________________________

cc:      Liberty Media Corporation




                                      C-2
<PAGE>   33
                                                                       EXHIBIT D


                  FORM OF TRANSFER CERTIFICATE FOR TRANSFER OR
                 EXCHANGE FROM TEMPORARY REGULATION S DEBENTURE
                             TO RULE 144A DEBENTURE


The Bank of New York
101 Barclay Street
Floor 21 West
New York, New York  10286

                  Re:      Liberty Media Corporation
                           $550,000,000 3-1/2% Senior Exchangeable Debentures
                           due 2031 (the "Debentures")

         Reference is hereby made to the Indenture dated as of July 7, 1999
between THE BANK OF NEW YORK (the "Trustee") and LIBERTY MEDIA CORPORATION (the
"Company") (as supplemented by the Fifth Supplemental Indenture, dated as of
January 11, 2001, between the Company and the Trustee, the "Indenture").
Capitalized terms not defined in this Certificate shall have the meanings given
to them in the Indenture.

         This Certificate relates to ______________________________________
Original Principal Amount of Debentures which are held in the form of the
Temporary Regulation S Debenture (CUSIP No. ___) with [Euroclear/Clearstream,
Luxembourg] (ISIN Code [___]) (Common Code [___]) through the Depository by or
on behalf of _____________ as beneficial owner (the "Transferor"). The
Transferor has requested an exchange or transfer of its interest in the
Debentures for an interest in the Rule 144A Debenture (CUSIP NO. [___]).

         In connection with such request, and in respect of such Debentures, the
Transferor does hereby certify that such transfer is being effected in
accordance with the transfer restrictions set forth in the Indenture and
pursuant to and in accordance with Rule 144A under the United States Securities
Act of 1933, as amended (the "Securities Act"), to a transferee that the
Transferor reasonably believes is purchasing the Debentures for its own account
or an account with respect to which the transferee exercises sole investment
discretion and the transferee and any such account is a "qualified institutional
buyer" within the meaning of Rule 144A, in each case in a transaction meeting
the requirements of Rule 144A and in accordance with any applicable securities
laws of any state of the United States or any other jurisdiction.

         This Certificate and the statements contained herein are made for your
benefit and the benefit of the Company and the initial purchaser of the
Debentures being transferred.

                                        [Insert Name of Transferor]


                                        By:_____________________________________
                                           Name:
                                           Title:

Dated: _________________________
cc:    Liberty Media Corporation


                                       D-1
<PAGE>   34
                                                                       EXHIBIT E



                       FORM OF CLEARING SYSTEM CERTIFICATE


                  Re:      Liberty Media Corporation
                           $550,000,000 3-1/2% Senior Exchangeable Debentures
                           due 2031 (the "Debentures")


         Reference is hereby made to the Indenture dated as of July 7, 1999
between THE BANK OF NEW YORK (the "Trustee") and LIBERTY MEDIA CORPORATION (the
"Company") (as supplemented by the Fifth Supplemental Indenture, dated as of
January 11, 2001, between the Company and the Trustee, the "Indenture").
Capitalized terms not defined in this Certificate shall have the meanings given
to them in the Indenture.

         This is to certify that, based solely on certifications we have
received in writing, by tested telex or by electronic transmission from member
organizations appearing in our records as persons being entitled to a portion of
the principal amount set forth below (our "Member Organizations") substantially
to the effect set forth in the Indenture, as of the date hereof,
$_________________ aggregate Original Principal Amount of Debentures represented
by the Temporary Regulation S Global Debenture is owned by (a) non-U.S. Persons
or (b) U.S. Persons who purchased such Debentures in transactions that did not
require registration under the United States Securities Act of 1933, as amended
(the "Securities Act"). As used in this paragraph, the term "U.S. Person" has
the meaning given to it by Regulation S under the Securities Act.(1)

         We further certify (i) that we are not making available herewith for
payment of interest any portion of a Temporary Regulation S Global Debenture
excepted in such certifications and (ii) that as of the date hereof we have not
received any notification from any of our Member Organizations to the effect
that the statements made by such Member Organizations with respect to any
portion of the Temporary Regulation S Global Debenture submitted herewith for
payment of interest are no longer true and cannot be relied upon as the date
hereof.



----------

         (1)      Note: Unless Euroclear and Clearstream, Luxembourg are
                  otherwise informed by the Initial Purchaser or the Trustee,
                  the Standard Long-Form Certification set out in the Operating
                  Procedures of Euroclear will be deemed to meet the
                  requirements of this sentence.




                                      E-1
<PAGE>   35
         We understand that this certification is required in connection with
certain securities laws of the United States. In connection therewith, if
administrative or legal proceedings are commenced or threatened in connection
with which this certification is or would be relevant, we irrevocably authorize
you to produce this certification to any interested party in such proceedings.

                                        Yours faithfully,


                                        [EUROCLEAR BANK,
                                        as operator of the Euroclear System]
                                        or
                                        [CLEARSTREAM BANKING,
                                        societe anonyme]



                                        By:_____________________________________


Dated:  ______________________(2)




----------

         (2)      Not earlier than 15 days prior to the relevant Interest
                  Payment Date or Redemption Date, as the case may be.




                                      E-2
<PAGE>   36
                                                                       EXHIBIT F


                   FORM OF CERTIFICATE OF BENEFICIAL OWNERSHIP


                  Re:      Liberty Media Corporation
                           $550,000,000 3-1/2% Senior Exchangeable Debentures
                           due 2031 (the "Debentures")


         Reference is hereby made to the Indenture dated as of July 7, 1999
between THE BANK OF NEW YORK (the "Trustee") and LIBERTY MEDIA CORPORATION (the
"Company") (as supplemented by the Fifth Supplemental Indenture, dated as of
January 11, 2001, between the Company and the Trustee, the "Indenture").
Capitalized terms not defined in this Certificate shall have the meanings given
to them in the Indenture.

         This is to certify that as of the date hereof, and except as set forth
below, the above-captioned Securities held by you for our account are
beneficially owned by (a) non-U.S. person(s) or (b) U.S. person(s) who purchased
the Debentures in transactions which did not require registration under the
Securities Act of 1933, as amended (the "Act"). As used in this paragraph, the
term "U.S. person" has the meaning given to it by Regulation S under the
Securities Act.

         We undertake to advise you promptly by tested telex or by electronic
transmission on or prior to the date on which you intend to submit your
certification relating to the Debentures held by you for our account in
accordance with your operating procedures if any applicable statement herein is
not correct on such date, and in the absence of any such notification it may be
assumed that this certification applies as of such date.

         This certification excepts and does not relate to $____________________
of such interest in the above Debentures in respect of which we are not able to
certify and as to which we understand exchange and delivery of definitive
Debentures (or, if relevant, exercise of any rights or collection of any
interest) cannot be made until we do so certify.




                                      F-1
<PAGE>   37
         We understand that this certification is required in connection with
certain securities laws of the United States. In connection therewith, if
administrative or legal proceedings are commenced or threatened in connection
with which this certification is or would be relevant, we irrevocably authorize
you to produce this certification to any interested party in such proceedings.

Date: _____________________________(3)

                                        By:_____________________________________

         As, or as agent for, the beneficial owner(s) of the Debentures to which
this certificate relates.




----------

         (3)      Not earlier than 15 days prior to the certification event to
                  which the certification relates.




                                      F-2
<PAGE>   38
                                                                       EXHIBIT G

                          [FORM OF NOTICE OF EXCHANGE]


The Bank of New York
101 Barclay Street
New York, NY 10286

                  Re:      $550,000,000 3-1/2% Senior Exchangeable
                           Debentures due 2031 (the "Debentures")

Gentlemen:


         The undersigned Holder of debentures hereby gives notice of its
intention to exchange $______________ aggregate Original Principal Amount of
Debentures. This notice, once delivered to the Exchange Agent, is irrevocable.

         If Reference Shares or any other securities are to be delivered as part
of this exchange, they should be delivered to:

         If cash is to be paid as part of this exchange, it should be sent to:

         Any communication to the Holder in connection with this exchange should
be directed to:

                                        Very truly yours,

                                        [Name of Holder]


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


Date of Notice of Exchange:




                                       G-1