Exhibit 4.10


                          SECOND SUPPLEMENTAL INDENTURE



            THIS SECOND SUPPLEMENTAL INDENTURE (this "Supplement"), dated as of
_____ __, 2002, between AT&T Corp., a corporation duly organized and validly
existing under the laws of the State of New York (the "Company"), and The Bank
of New York, a corporation duly organized and validly existing under the laws of
New York, as Trustee (the "Trustee"), as Trustee under the Indenture, dated as
of September 7, 1990, between the Company and the Trustee, as amended by the
First Supplemental Indenture, dated as of October 30, 1992, between the Company
and the Trustee (the "Indenture"). Capitalized terms used in this Supplement and
not otherwise defined herein shall have the meanings set forth in the Indenture.


                                    RECITALS

            WHEREAS, the Company has previously issued $2,000,000,000 5.625%
notes due 2004, $400,000,000 6.75% notes due 2004, $300,000,000 7.000% notes due
May 15, 2005, $500,000,000 7.500% notes due June 1, 2006, $500,000,000 7.75%
notes due March 1, 2007, $3,000,000,000 6.000% notes due 2009, $500,000,000
8.125% debentures due January 15, 2022, $500,000,000 8.125% debentures due July
15, 2024, $300,000,000 8.350% debentures due 2025, $50,000,000 8.000%
medium-term notes, Series A due May 15, 2025, $25,000,000 7.750% medium-term
notes, Series A due May 15, 2025, $3,000,000,000 6.500% notes due 2029,
$676,000,000 8.625% debentures due December 1, 2031 and $10,563,000 FRN
medium-term notes, Series A due 2054 (collectively, the "Notes") in accordance
with the terms of the Indenture;

            WHEREAS, the Company has entered into an Agreement and Plan of
Merger by and among the Company, AT&T Broadband Corp. ("AT&T Broadband"),
Comcast Corporation, AT&T Broadband Acquisition Corp., Comcast Acquisition Corp
and AT&T Comcast Corporation ("AT&T Comcast") dated as of December 19, 2001, as
it may be amended, supplemented or otherwise modified from time to time, whether
prior to or after the date hereof (the "Merger Agreement");


            WHEREAS, in connection with the Merger Agreement, the Company and
AT&T Broadband Corp, have also entered into a Separation and Distribution
Agreement, dated as of December 19, 2001, as it may be amended, supplemented or
otherwise modified from time to time, whether prior to or after the date hereof
(the "Separation and Distribution Agreement");


            WHEREAS, in accordance with Section 9.02 of the Indenture, the
Company and the Trustee may amend the Indenture with the written consent of the
holders of at least a majority in principal amount of the Notes of each Series
affected by such supplemental indenture (with each Series voting as a class);


            WHEREAS, the Company has solicited and obtained consents from the
Holders to certain amendments to the Indenture pursuant to an exchange offer and
consent solicitation made pursuant to a prospectus dated ____________, 2002, as
amended, supplemented or otherwise modified from time to time, whether prior to
or after the date hereof, of the Company and the other parties named therein;


            WHEREAS, the holders of a majority in principal amount of each of
the Series of Notes have consented to the amendments to the Indenture contained
herein; and


            WHEREAS, the Company desires to amend the Indenture in accordance
with Section 9.02 thereof and has determined that the requirements of Sections
9.02, 10.04 and 10.05 of the Indenture have been satisfied and has requested the
Trustee to join with it in the execution and delivery of this Supplement; all
requirements necessary to make this Supplement a valid instrument, in accordance
with its terms, have been met; and the execution and delivery hereof have been
in all respects duly authorized.


            NOW, THEREFORE, for good and valuable consideration the sufficiency
of which is hereby recognized, the Company covenants and agrees with the Trustee
as follows:

                                   ARTICLE I

                           AMENDMENTS TO THE INDENTURE

            Section 1.1 AT&T Comcast Transaction. The Company and the Trustee
hereby amend the Indenture to add the following section to Article 5 of the
Indenture:

            "Section 5.05 AT&T Comcast Transaction. The Trustee and the Holders
hereby acknowledge that the Company is engaging in a series of transactions
contemplated by the Separation and Distribution Agreement, dated as of December
19, 2001, as it may be amended, supplemented or otherwise modified from time to
time, whether prior to or after the date hereof (the "Separation and
Distribution Agreement"), the Agreement and Plan of Merger by and among the
Company, AT&T Broadband Corp., Comcast Corporation, AT&T Broadband Acquisition
Corp., Comcast Acquisition Corp. and AT&T Comcast Corporation dated as of
December 19, 2001, as it may be amended, supplemented or otherwise modified from
time to time, whether prior to or after the date hereof (the "Merger
Agreement"), including without limitation the Separation and the Distribution
(as such terms are defined in the Separation and Distribution Agreement) and the
other Transaction Agreements (as such term is defined in the Merger Agreement)
as they may be amended, supplemented or otherwise modified from time to time,
whether prior to or after the date hereof (collectively, the "Covered
Transactions"). Each of the Company, the Trustee and the Holders agree that the
Covered Transactions, individually or together, (a) will not result in a
consolidation, merger, sale, conveyance or other transfer of property of the
Company (including stock of subsidiaries) as an entirety or substantially as an
entirety for purposes of Section 5.01 of this Indenture or any other provision
of this Indenture or any Security, and (b) will not violate Sections 5.01, 5.02
or 5.03 of this Indenture or any other provision of this Indenture or any
Security, regardless of whether any person assumes any of the Indebtedness
outstanding under this Indenture or any other obligation under this Indenture or
any Security."


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                                   ARTICLE II

                                  MISCELLANEOUS


            Section 2.1 Effectiveness of Provisions. Upon the execution of this
Supplement by the Company and the Trustee, the Indenture shall be modified in
accordance herewith, and this Supplement shall form a part of the Indenture for
all purposes, and every holder of Securities heretofore or hereafter
authenticated and delivered under the Indenture shall be bound hereby.


            Section 2.2 Indenture Remains in Full Force and Effect. Except as
supplemented hereby, all provisions in the Indenture shall remain in full force
and effect.

            Section 2.3 Execution of Supplement. This Supplement is executed and
shall be construed as an indenture supplemental to the Indenture and, as
provided in the Indenture, this Supplement forms a part thereof.

            Section 2.4 Conflict with Trust Indenture Act. If and to the extent
that any provision of this Supplement limits, qualifies or conflicts with the
duties imposed by any of Sections 310 to 317, inclusive, of the Trust Indenture
Act, such imposed duties shall control.

            Section 2.5 Separability Clause. In case any one or more of the
provisions contained in this Supplement, the Indenture or in the Securities of
any series shall for any reason be held to be invalid, illegal or unenforceable
in any respect, such invalidity, illegality or unenforceability shall not affect
any other provisions of this Supplement, the Indenture or of such Securities,
but this Supplement, the Indenture and such Securities shall be construed as if
such invalid or illegal or unenforceable provision had never been contained
herein or therein.

            Section 2.6 Benefits of the Supplement. Nothing in this Supplement
or in the Indenture, express or implied, shall give to any person, other than
the parties hereto and their successors hereunder and the holders of Securities
(to the extent specified herein or therein), any benefit or any legal or
equitable right, remedy or claim under this Supplement.

            Section 2.7 Successors and Assigns. All covenants and agreements in
this Supplement by the Company shall bind its successors and assigns, whether so
expressed or not.


            Section 2.8 Governing Law. This Supplement shall be governed by, and
construed in accordance with, the laws of the State of New York.


            Section 2.9 Counterparts. This Supplement may be executed in any
number of counterparts, each of which is an original; but all such counterparts
shall together constitute but one and the same instrument.

            Section 2.10 Miscellaneous. Except as expressly supplemented by this
Supplement, the Indenture shall remain unchanged and in full force and effect.


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            IN WITNESS WHEREOF, the Company and the Trustee have caused this
Supplement to be duly executed by their respective officers as of the day and
year first written above.

                                      AT&T CORP.




                                      By:________________________________
                                          Name:
                                          Title:

[CORPORATE SEAL]

Attest:

By:_____________________


                                      THE BANK OF NEW YORK, as Trustee


                                      By:________________________________
                                          Name:
                                          Title:

[CORPORATE SEAL]

Attest:

By:_____________________



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