<PAGE>

                                                                 Exhibit 10.25
                           ______________________
                           ______________________

                          NEWS AMERICA INCORPORATED,


                                   Company,

                         THE NEWS CORPORATION LIMITED,
                              FEG HOLDINGS, INC.,
                        FOX ENTERTAINMENT GROUP, INC.,
                        HARPERCOLLINS PUBLISHERS INC.,
                              HARPERCOLLINS (UK),
                       NEWS AMERICA MARKETING FSI, INC.,
                            NEWS INTERNATIONAL plc,
                                 NEWS LIMITED,
                      NEWS PUBLISHING AUSTRALIA LIMITED,
                             NEWS SECURITIES B.V.,
                             NEWSCORP INVESTMENTS,

                                  Guarantors
                                      and

                             THE BANK OF NEW YORK,

                                    Trustee

                   -----------------------------------------
                         SECOND SUPPLEMENTAL INDENTURE

                         Dated as of February 14, 2001

                   Amending and Supplementing the Indenture

                         Dated as of November 12, 1996
                   -----------------------------------------
                 5% Subordinated Discount Debentures due 2016

                            ______________________
                            ______________________
<PAGE>

          SECOND SUPPLEMENTAL INDENTURE, dated as of February 14, 2001, among
News America Incorporated, a Delaware corporation (the "Company") with its
principal office located at 1211 Avenue of the Americas, New York, NY 10036, The
News Corporation Limited, a South Australia, Australia corporation (A.C.N. 007
910 330) ("News Corporation"), FEG Holdings, Inc., Fox Entertainment Group,
Inc., HarperCollins Publishers Inc., HarperCollins (UK), News America Marketing
FSI, Inc., News International plc, News Limited, News Publishing Australia
Limited, News Securities B.V., Newscorp Investments, and The Bank of New York, a
New York banking corporation (the "Trustee"), amending and supplementing the
Indenture, dated as of November 12, 1996 (the "Original Indenture"), among the
Company, the guarantors named therein (collectively, the "Guarantors") and the
Trustee, which provided for the issuance of the Company's 5% Subordinated
Discount Debentures due November 12, 2016 (the "Securities").  (The Original
Indenture as supplemented by the First Supplemental Indenture, dated as of March
2, 2000, and this Second Supplemental Indenture and as may hereafter be
supplemented is referred to herein as the or this "Indenture").  Capitalized
terms used herein and not otherwise defined herein have the meanings ascribed
thereto in the Indenture.

                                   RECITALS:

     WHEREAS, effective November 22, 2000, Fox Broadcasting Company, Fox
Television Holdings, Inc., The Herald and Weekly Times Limited, Nationwide News
Pty Limited, News Group Newspapers Limited, News T Investments, Inc., News
Triangle Finance, Inc., Newscorp Overseas Limited, Twentieth Century Fox Film
Corporation, and Twentieth Century Fox Home Entertainment, Inc., each a
Guarantor under the Indenture, were each eliminated from the terms of the
Guarantee and as Guarantors under the Indenture; and

     WHEREAS, effective November 22, 2000, FEG Holdings, Inc. was added as a
Guarantor under the Indenture; and

     WHEREAS, the provisions of this Second Supplemental Indenture shall not
adversely affect the interests of the Holders of Securities in any material
respect; and

     WHEREAS, the Original Indenture is subject to the provisions of the United
States Trust Indenture Act of 1939, as amended (the "TIA"), that are required to
be part of the Original Indenture and the Indenture shall, to the extent
applicable, be governed by such provisions; and

     WHEREAS, the Company has duly authorized the execution and delivery of this
Second Supplemental Indenture and has done all things necessary to make this
Second Supplemental Indenture a valid agreement in accordance with its terms.
<PAGE>

     NOW, THEREFORE, THIS INDENTURE WITNESSETH:

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

                                  ARTICLE ONE

                               ORIGINAL INDENTURE

     SECTION 101.   Effect of Original Indenture.
                    -----------------------------

     Except as specifically provided in this Second Supplemental Indenture, the
Original Indenture, as heretofore supplemented and amended, shall remain in full
force and effect.

                                  ARTICLE TWO

                          AMENDMENTS TO THE INDENTURE

     SECTION 201.   Release of Certain Guarantors.
                    ------------------------------

     In accordance with Section 901 of the Original Indenture, Fox Broadcasting
Company, Fox Television Holdings, Inc., The Herald and Weekly Times Limited,
Nationwide News Pty Limited, News Group Newspapers Limited, News T Investments,
Inc., News Triangle Finance, Inc., Newscorp Overseas Limited, Twentieth Century
Fox Film Corporation, and Twentieth Century Fox Home Entertainment, Inc., are
each hereby eliminated as Guarantors under the Indenture.

     SECTION 202.   Addition of Guarantor.
                    ----------------------

     In accordance with Section 901 of the Original Indenture, FEG Holdings,
Inc., is hereby added as a Guarantor under the Indenture.

     SECTION 203.   References in the Indenture.
                    ----------------------------

     By reason of the elimination of Fox Broadcasting Company, Fox Television
Holdings, Inc., The Herald and Weekly Times Limited, Nationwide News Pty
Limited, News Group Newspapers Limited, News T Investments, Inc., News Triangle
Finance, Inc., Newscorp Overseas Limited, Twentieth Century Fox Film
Corporation, and Twentieth Century Fox Home Entertainment, Inc. as Guarantors
pursuant to Section 201 hereof, and the addition of FEG Holdings, Inc. as a
Guarantor pursuant to Section 202 hereof and the continuation, as Guarantors, of
the Guarantors under the Indenture, all references in the Indenture to the
"Guarantors" are hereby deemed to refer to the following entities and all such
references to each or any "Guarantor" are hereby deemed to refer to each of such
entities:

     Name                           Jurisdiction of Incorporation
     ----                           -----------------------------

The News Corporation Limited                  South Australia, Australia
FEG Holdings, Inc.                            Delaware

                                      -3-
<PAGE>

Fox Entertainment Group, Inc.                 Delaware
HarperCollins Publishers Inc.                 Delaware
HarperCollins (UK)                            England
News America Marketing FSI, Inc.              Delaware
News International plc                        England
News Limited                                  South Australia, Australia
News Publishing Australia Limited             Delaware
News Securities B.V.                          Netherlands
Newscorp Investments                          England

                                 ARTICLE THREE

                                 MISCELLANEOUS

     SECTION 301.   Effect of Headings.
                    -------------------

     The Article and Section headings herein are for convenience of reference
only and shall not effect the construction hereof.

     SECTION 302.   Governing Law.
                    --------------

     Subject to the following sentence, this Second Supplemental Indenture shall
be governed by, and construed in accordance with, the laws of the State of New
York, without regard to principles of conflicts of laws.  This Second
Supplemental Indenture is subject to the provisions of the TIA that are required
to be part of the Original Indenture and shall, to the extent applicable, be
governed by such provisions.

     SECTION 303.   Counterparts.
                    -------------

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

                                      -4-
<PAGE>

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

                              News America Incorporated

                              By: /s/ Arthur M. Siskind
                                  -----------------------------
                                Name:  Arthur M. Siskind
                                Title: Senior Executive Vice President

                              Executed as a Deed in New York,
                                    New York

                              The News Corporation Limited,
                                    as Guarantor

                              FEG Holdings, Inc.,
                                    as Guarantor


                              Fox Entertainment Group, Inc.
                                    as Guarantor

                              HarperCollins Publishers Inc.,
                                    as Guarantor

                              HarperCollins (UK),
                                    as Guarantor

                              News America Marketing FSI, Inc.,
                                    as Guarantor

                              News International plc,
                                    as Guarantor

                              News Limited,
                                    as Guarantor

                                      -5-
<PAGE>

                              News Publishing Australia Limited,
                                    as Guarantor

                              News Securities B.V.,
                                    as Guarantor

                              Newscorp Investments,
                                    as Guarantor

                              By: /s/ Arthur M. Siskind
                                  ------------------------------
                                  Name:  Arthur M. Siskind
                                  Title: Senior Executive Vice President,
                                         News America
                                         for the Guarantors




                              The Bank of New York

                              By: /s/ Kisha A. Holder
                                  ------------------------------
                                  Name:  KISHA A. HOLDER
                                  Title: ASSISTANT TREASURER

                                      -6-
<PAGE>

STATE OF NEW YORK   )
                    ) ss.:
COUNTY OF NEW YORK  )

     On this 14/th/ day of February, 2001, before me personally appeared Arthur
M. Siskind who acknowledged himself to be a Senior Executive Vice President of
News America Incorporated, and that he, as such Senior Executive Vice President,
being authorized so to do, executed the foregoing instrument for the purposes
therein contained, by signing the name of the corporation by himself as such
Senior Executive Vice President.

     IN WITNESS WHEREOF, I hereunto set my hand and official seal.



Notary Public                                 /s/ Camille Joseph
                                              ------------------------

[Notarial Seal]

                                      -7-
<PAGE>

STATE OF NEW YORK   )
                    ) ss.:
COUNTY OF NEW YORK  )

     On the _____ day of March 2001, before me personally came KISHA A. HOLDER,
                                                               ---------------
to me known, who, being by me duly sworn, did depose and say that s/he is a
ASSISTANT TREASURER of The Bank of New York, the New York banking corporation
-------------------
described in and which executed the foregoing instrument by authority of the
Board of Directors of said New York banking corporation, and that s/he signed
her/his name thereto by like authority.

     IN WITNESS WHEREOF, I hereunto set my hand and official seal.

Notary Public
                              William J. Cassels

[Notarial Seal]

                              WILLIAM J. CASSELS
                       Notary Public, State of New York
                                No 01CA5027729
                         Qualified in Bronx County
                       Commission Expries May 16, 2002

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