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                                                                   EXHIBIT 10.24

                              EIGHTH SUPPLEMENT TO

                              INTER-GROUP AGREEMENT

                                between and among

                                   AT&T CORP.,

                                on the one hand,

                                       and

                           LIBERTY MEDIA CORPORATION,

                             LIBERTY MEDIA GROUP LLC

                      and each Covered Entity listed on the

                             signature pages hereof,

                               on the other hand,

                          dated as of November 20, 2000
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                              EIGHTH SUPPLEMENT TO

                              INTER-GROUP AGREEMENT

                  Agreement dated as of November 20, 2000 (this "Agreement")
between AT&T Corp., a New York corporation ("AT&T"), for itself and on behalf of
the members of the Common Stock Group, on the one hand, and Liberty Media
Corporation, a Delaware corporation ("LMC"), Liberty Media Group LLC, a Delaware
limited liability company, and for so long as such Covered Entity remains a
Covered Entity under the applicable provisions of the AT&T Charter Amendment,
each Covered Entity listed on the signature pages hereof (collectively, the
"Liberty Media Parties"), for themselves and, in the case of LMC, on behalf of
the other members of the Liberty Media Group, on the other hand.

                  WHEREAS, AT&T and the Liberty Media Parties are parties to
that certain Inter-Group Agreement, dated as of March 9, 1999 (the "Inter-Group
Agreement"), as supplemented and modified by (i) the First Supplement to
Inter-Group Agreement, dated as of May 28, 1999, as such First Supplement has
been amended, (ii) the Second Supplement to Inter-Group Agreement, dated as of
September 24, 1999, (iii) the Third Supplement to Inter-Group Agreement, dated
as of October 20, 1999, (iv) the Fourth Supplement to Inter-Group Agreement,
dated as of December 6, 1999, (v) the Fifth Supplement to Inter- Group
Agreement, dated as of December 10, 1999, (vi) the Sixth Supplement to
Inter-Group Agreement, dated as of December 30, 1999, and (vii) the Seventh
Supplement to Inter-Group Agreement, dated as of July 25, 2000, which
establishes certain terms and conditions concerning the responsibilities and
obligations of each Group to the other as well as certain additional provisions
concerning the Groups' relationships with each other;
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                  WHEREAS, LMC has requested AT&T to adopt an incentive plan
known as the "AT&T Corp. Liberty Media Group 2000 Incentive Plan" (the "Liberty
Plan"), in the form attached hereto as Exhibit A;

                  WHEREAS, AT&T and the Liberty Media Parties desire to
supplement and modify the Inter-Group Agreement to address the responsibilities
and obligations of each Group relating to the Liberty Plan;

                  NOW, THEREFORE, in consideration of the foregoing and the
mutual covenants and agreements contained herein, and intending to be legally
bound hereby, AT&T and the Liberty Media Parties hereby agree as follows:

                                    ARTICLE I
                    OBLIGATIONS RELATING TO THE LIBERTY PLAN

                  SECTION 1.1. Certain Liabilities Relating to the Liberty Plan.

                  (a) Subject to the last sentence of this subsection (a), all
Liabilities arising out of or related to the Liberty Plan, any registration
statement on Form S-8 (or any successor form) covering the issuance of AT&T
Liberty Tracking Shares underlying grants pursuant to the Liberty Plan (a
"Registration Statement") and any incentive awards granted pursuant to the
Liberty Plan in accordance with the provisions thereof shall, as between the
Common Stock Group and the Liberty Media Group, be Liabilities of the Liberty
Media Group and shall be considered "Stock Incentives" for purposes of Section
1.4(a)(ii) of the Inter-Group Agreement. It is understood and agreed that all
incentive awards granted under the Liberty Plan will be granted to persons who
are officers, employees or consultants of the Liberty Media Group, and whenever
any such incentive award is exercised or settled, it shall be considered, for
purposes of Section 1.4(a)(ii) of the Inter-Group Agreement, to have been
exercised or settled by a person who is an officer, employee or consultant of
the Liberty Media Group or by a person who is no longer an officer, employee or
consultant

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of the Liberty Media Group but who was an officer, employee or consultant of the
Liberty Media Group on the date of such person's last employment by either Group
(as defined in the Inter-Group Agreement). Notwithstanding the foregoing, as
between the Common Stock Group and the Liberty Media Group, the Common Stock
Group shall be responsible for any Liabilities to the extent arising out of or
relating to any false or misleading statement of a material fact contained in or
incorporated by reference into a Registration Statement or the omission to state
or incorporate by reference therein a material fact required to be stated
therein or necessary to make the statements therein, in light of the
circumstances in which they were made, not misleading, in each case, at the time
such Registration Statement becomes effective and only to the extent that such
false or misleading statement or omission relates to AT&T or any member of the
Common Stock Group.

                  (b) The Liberty Media Group shall be responsible for, and
shall reimburse the Common Stock Group for, any and all reasonable costs, fees
and expenses incurred by AT&T or any member of the Common Stock Group in
connection with: (i) the review and approval of the Liberty Plan and this
Agreement; (ii) the grant of awards pursuant to the Liberty Plan; (iii) the
review and filing, at the request of the Liberty Media Parties, of a
registration statement or registration statements on Form S-8 (or any successor
form) covering solely the issuance of AT&T Liberty Tracking Shares underlying
awards granted pursuant to the Liberty Plan; and (iv) all other fees and
expenses related thereto, including in each case any internal costs, fees and
expenses (which shall be determined in any reasonable manner developed
by AT&T for tracking such internal costs, fees and expenses), and in each case
such costs, fees and expenses to be reimbursed promptly upon receipt of a
statement therefor.

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                  SECTION 1.2. Issuance of AT&T Liberty Tracking Shares. AT&T
shall be responsible for the issuance and delivery to the transfer agent of any
AT&T Liberty Tracking Shares that become deliverable in connection with the
exercise or settlement of any awards granted pursuant to the Liberty Plan.

                                   ARTICLE II
                                   DEFINITIONS

                  SECTION 2.1. Certain Definitional Provisions. Capitalized
terms used herein without definition have the meanings ascribed to such terms in
the Inter-Group Agreement. The language used in this Agreement shall be deemed
to be the language chosen by the parties to express their mutual intent, and no
rule of strict construction shall be applied against any party. Any references
to any statute or law shall also refer to all rules and regulations promulgated
thereunder, unless the context requires otherwise. Whenever the context may
require, any pronoun shall include the corresponding masculine, feminine and
neuter forms. The words "include," "includes," and "including" shall be deemed
to be followed by the phrase "without limitation". The words "hereof," "herein"
and "hereunder" and words of similar import when used in this Agreement shall
refer to this Agreement as a whole and not to any particular provision of this
Agreement, and Article and Section references are to this Agreement unless
otherwise specified. The meanings given to terms defined herein shall be equally
applicable to both the singular and plural forms of such terms. Unless the
context shall otherwise require, any references to any agreement or other
instrument or statute or regulation are to it as amended and supplemented from
time to time (and, in the case of a statute or regulation, to any successor
provisions). Any reference in this Agreement to a "day" or number of "days"
(without the explicit qualification of "business") shall be interpreted as a
reference to a calendar day or number of calendar days. If any action or notice
is to be taken or given on or

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by a particular calendar day, and such calendar day is not a business day, then
such action or notice shall be deferred until, or may be taken or given on, the
next business day.

                                   ARTICLE III
                                  MISCELLANEOUS

                  SECTION 3.1. Notices. All notices, requests, demands or other
communications required by or otherwise with respect to this Agreement shall be
in writing and shall be deemed to have been given to any party when delivered
personally (by courier service or otherwise), when delivered by telecopy and
confirmed by return telecopy, or upon the receipt after being mailed by
first-class mail, postage prepaid and return receipt requested in each case to
the applicable addresses set forth below:

         If to AT&T or any member of the Common Stock Group:
                  AT&T Corp.
                  295 North Maple Avenue
                  Basking Ridge, New Jersey  07920
                  Attention:     Vice President-Law
                                 and Corporate Secretary
                  Facsimile:     (908) 221-6618

         with a copy to:

                  Wachtell, Lipton, Rosen & Katz
                  51 West 52nd Street
                  New York, New York 10019
                  Attention:     Richard D. Katcher, Esq.
                                 Steven A. Rosenblum, Esq.
                                 David M. Silk, Esq.
                  Facsimile:     (212) 403-2000

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         If to LMC or any member of the Liberty Media Group:

                  Liberty Media Corporation
                  9197 South Peoria Street
                  Englewood, Colorado 80112

                  Attention:     Charles Y. Tanabe, Esq.
                  Facsimile:     (720) 875-5382

         with a copy to:

                  Baker Botts L.L.P.
                  599 Lexington Avenue
                  New York, New York 10022
                  Attention:     Robert W. Murray, Esq.
                  Facsimile:     (212) 705-5125

or such address as such party shall have designated by notice so given to each
other party.

                  SECTION 3.2. Amendments; No Waivers. (a) This Agreement shall
be amended, changed, supplemented, waived or otherwise modified only by an
instrument in writing signed by each of AT&T and LMC (and following a Triggering
Event (as defined in the Inter-Group Agreement), Liberty Media Group LLC).

                  (b) No failure or delay by any party in exercising any right,
power or privilege hereunder shall operate as a waiver thereof nor shall any
single or partial exercise thereof preclude any other or further exercise
thereof or the exercise of any other right, power or privilege. The rights and
remedies herein provided shall be cumulative and not exclusive of any rights or
remedies provided by law.

                  SECTION 3.3. Successors and Assigns. Neither this Agreement
nor any of the rights or obligations under this Agreement shall be assigned, in
whole or in part, by any party without the prior written consent of the other
parties hereto; provided, however, that the assignment of its rights and
obligations under this Agreement by LMC or any Covered Entity (as defined in the
Inter-Group Agreement) to Liberty Media Group LLC in connection with the
transactions

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contemplated by the Contribution Agreement shall not require the consent of
AT&T. Subject to the foregoing, the provisions of this Agreement shall be
binding upon and inure to the benefit of the parties hereto and their respective
successors and assigns.

                  SECTION 3.4. Governing Law; Consent to Jurisdiction. This
Agreement and all disputes hereunder shall be governed by and construed and
enforced in accordance with the internal laws of the State of Delaware, without
regard to the principles of conflicts of laws. Each party hereto irrevocably and
unconditionally consents to submit to the exclusive jurisdiction of the United
States District Court for the District of Delaware or the Chancery Court of the
State of Delaware in any action, suit or proceeding arising in connection with
this Agreement, and agrees that any such action, suit or proceeding shall be
brought only in such court (and waives any objection based on forum non
coveniens or any other objection to venue therein); provided, however, that such
consent to jurisdiction is solely for the purpose referred to in this Section
3.4 and shall not be deemed to be a general submission to the jurisdiction of
said courts or of the State of Delaware other than for such purpose. AT&T and
LMC each hereby waive any right to a trial by jury in connection with any such
action, suit or proceeding.

                  SECTION 3.5. Counterparts; Effectiveness. This Agreement may
be executed in any number of counterparts, each of which shall be deemed to be
an original, but all of which together shall constitute one instrument. This
Agreement shall become effective when each party hereto shall have received
counterparts thereof signed by the other party hereto.

                  SECTION 3.6. Specific Performance. Each of AT&T and LMC
acknowledges and agrees that money damages are not an effective remedy for
violations of this Agreement and that any party may, in its sole discretion,
apply to a court of competent jurisdiction for specific performance or
injunctive or such other relief as such court may deem just and proper in order
to

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enforce this Agreement or prevent any violation hereof and, to the extent
permitted by applicable Law, each party waives any objection to the imposition
of such relief.

                  SECTION 3.7. Remedies Cumulative. All rights, powers and
remedies provided under this Agreement or otherwise available in respect hereof
at law or in equity shall be cumulative and not alternative, and the exercise or
beginning of the exercise of any thereof by any party shall not preclude the
simultaneous or later exercise of any other such right, power or remedy by such
party.

                  SECTION 3.8. Termination. This Agreement shall remain in full
force and effect until such time as no shares of Class A Liberty Group Stock or
Class B Liberty Group Stock are outstanding and upon termination, no party shall
have any liability or further obligation to the other under this Agreement,
except that the provisions of Section 1.1(a) (to the extent of any Liabilities
described therein that arose at or prior to the termination of this Agreement or
under any provision of this Agreement that survives such termination) and this
Section 3.8 shall survive the termination of this Agreement. No termination of
this Agreement shall limit or otherwise affect the rights or obligations of the
parties to the Inter-Group Agreement.

                  SECTION 3.9. Cooperation. Each of AT&T and LMC covenants and
agrees with the other to use its reasonable best efforts to cause each member of
the Common Stock Group and each member of the Liberty Media Group, respectively,
to fulfill each of its respective obligations under this Agreement.

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

                                 AT&T CORP.



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

                                 LIBERTY MEDIA CORPORATION



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

                                 LIBERTY MEDIA GROUP LLC



                                 By:
                                    -------------------------------------------
                                    Name:
                                    Title:
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                                 Each of the following Covered Entities hereby
                                 executes this Agreement as a member of the
                                 Liberty Media Group to become a party to this
                                 Agreement for so long as it remains a Covered
                                 Entity under the applicable provisions of the
                                 AT&T Charter Amendment:

                                 LIBERTY SP, INC.



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

                                 LIBERTY AGI, INC.



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

                                 LMC INTERACTIVE, INC.



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