<PAGE>
                                                                    Exhibit 4.75

                          FIFTH SUPPLEMENTAL INDENTURE

         FIFTH SUPPLEMENTAL INDENTURE, dated as of February 25, 2004, among
CANWEST MEDIA INC., a corporation incorporated under the federal laws of Canada
(the "Issuer"), each of the New Guarantors (as defined herein); and The Bank of
New York, as trustee (the "Trustee").

         WHEREAS, in accordance with Section 11.04 of the Indenture relating to
the 10-5/8% Senior Subordinated Notes due 2011 of the Issuer, dated as of May
17, 2001, between the Company, the Trustee and the Guarantors (as defined
therein), as supplemented by supplemental trust indentures dated August 6, 2002,
February 27, 2003, April 23, 2003 and September 22, 2003 among the Issuer, the
Trustee and the New Guarantors (as defined therein) (such indenture and
supplemental indentures are collectively referred to as the "Indenture"), each
of the entities listed on Exhibit A hereto (each a "New Guarantor") desires to
guarantee the obligations of the Issuer with respect to the Notes on the terms
set forth in the Indenture;

         WHEREAS, the Boards of Directors of the Issuer and each of the New
Guarantors have authorized this Fifth Supplemental Indenture; and

         WHEREAS, all things necessary to make this Fifth Supplemental Indenture
a valid supplement to the Indenture according to its terms and the terms of the
Indenture have been done:

         NOW, THEREFORE, each party agrees as follows for the benefit of the
other parties and for the equal and ratable benefit of Holders of the Notes:

         Section 1. Guarantee. Each New Guarantor covenants and agrees to be
bound by and subject to the terms of the Indenture as if they had executed the
same as a Guarantor as of the date first set forth above.

         Section 2. Certain Defined Terms. All capitalized terms used and not
otherwise defined herein shall have the meanings ascribed to them in the
Indenture.

         Section 3. Governing Law. THIS FIFTH 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 LAW. EACH OF THE PARTIES HERETO
AGREES TO SUBMIT TO THE JURISDICTION OF THE COURTS OF THE STATE OF NEW YORK IN
ANY ACTION OR PROCEEDING ARISING OUT OF OR RELATING TO THIS FIFTH SUPPLEMENTAL
INDENTURE, THE NOTES OR THE GUARANTEES.

<PAGE>

         Section 4. Multiple Counterparts. The parties may sign multiple
counterparts of this Fifth Supplemental Indenture. Each signed counterpart shall
be deemed an original, but all of them together represent one and the same
agreement.

         IN WITNESS WHEREOF, the parties have caused this Fifth Supplemental
Indenture to be duly executed all as of the date and year first written above.

                                   CANWEST MEDIA INC.

                                   By:   /s/ JOHN MAGUIRE
                                         ---------------------
                                         Name: John Maguire
                                         Title: Chief Financial Officer

                                   MBS PRODUCTIONS INC.

                                   By:   /s/ PAMELA HARROD
                                         ---------------------
                                         Name: Pamela Harrod
                                         Title: Authorized Signing Officer

                                   THE BANK OF NEW YORK,
                                         not in its individual capacity, but
                                         solely as Trustee

                                   By:   /s/ VANESSA MACK
                                         ---------------------
                                         Name: Vanessa Mack
                                         Title: Assistant Vice President

                                       2
<PAGE>

                                                                       Exhibit A

New Guarantors

MBS Productions Inc.

                                       3