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                                                                    EXHIBIT 4.78

                        SENIOR SECURED CREDIT FACILITIES

                               CANWEST MEDIA INC.

                                  as Borrower

                                    - and -

                       CANWEST GLOBAL COMMUNICATIONS CORP.

                                  as Guarantor

                                     - and -

                      THE FINANCIAL INSTITUTIONS IDENTIFIED
                          ON THE SIGNATURE PAGES HERETO

                                   as Lenders

                                     - and -

                             THE BANK OF NOVA SCOTIA

         as Co-Lead Arranger, Joint Bookrunner and Administrative Agent

                                     - and -

                       CANADIAN IMPERIAL BANK OF COMMERCE
           as Co-Lead Arranger, Joint Bookrunner and Syndication Agent

                                     - and -

                              BANK OF AMERICA, N.A.

                       as Arranger and Documentation Agent

                            AMENDING AGREEMENT NO. 3

                           Dated as of March 27, 2003


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                            AMENDING AGREEMENT NO. 3

      This amending agreement no. 3 dated as of March 27, 2003 among CanWest
Media Inc. (the "Borrower"), as borrower, CanWest Global Communications Corp.
(the "Guarantor"), as guarantor, the Lenders (as defined below), and The Bank of
Nova Scotia, as administrative agent.

      WHEREAS The Bank of Nova Scotia, as administrative agent (in such
capacity, the "Administrative Agent") and such other Persons (as that term is
defined in the Credit Agreement hereinafter defined and referred to) as may from
time to time be parties to the Credit Agreement (collectively, together with The
Bank of Nova Scotia in its capacity as a lender, the "Lenders") agreed to make
certain credit facilities available to the Borrower upon the terms and
conditions contained in a credit agreement among the Borrower, the Guarantor,
the Administrative Agent and the Lenders dated as of November 7,2000 (as amended
by that certain amending agreement dated as of September 5, 2001, and that
certain amending agreement no. 2 dated as of July 15, 2002, the
"CreditAgreement");

      AND WHEREAS the Borrower has requested of the Administrative Agent and the
Lenders that the Credit Agreement be amended as hereinafter provided and the
Administrative Agent and the Lenders have agreed to such amendments to the
Credit Agreement on the terms and conditions set forth in this amending
agreement;

      NOW THEREFORE in consideration of the foregoing premises and other good
and valuable consideration, the receipt and sufficiency of which are
acknowledged, the Borrower, the Guarantor, the Administrative Agent and the
Lenders agree as follows:

1. Defined Terms. Capitalized terms used in this amending agreement no. 3 and
not otherwise defined shall have the respective meanings attributed to them in
the Credit Agreement.

2. Amendment to Section 1.01. Section 1.01 of the Credit Agreement is amended
effective as of this date as follows:

      (i)   by amending the definition of "Permitted Debt" by deleting clause
            (xiii) thereof and the word "and" immediately prior thereto, and
            inserting the following in their place:

            "(xiii) Senior Unsecured Debt, provided that, prior to the issuance
            of any Senior Unsecured Debt, the Administrative Agent shall have
            received an opinion of legal counsel to the Borrower that the
            issuance of such Senior Unsecured Debt does not breach the
            provisions of, or

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            otherwise cause a default under, any existing Senior Subordinated
            Debt, the HCN Notes or any existing Senior Unsecured Debt, in form
            and substance reasonably acceptable to the Administrative Agent and
            its legal counsel; and (xiv) such other Debt as agreed to by the
            Majority Lenders."

      (ii)  by amending the definition of "Permitted Distributions" by deleting
            clauses (vi) through (viii) thereof and inserting the following in
            its place:

            "(vi) payments on account of the principal amount of the HCN Notes
            referred to in clause (i) of the definition of HCN Notes, and
            accrued and unpaid interest relating to such HCN Notes repaid, from
            (y) amounts made available to the Borrower in accordance with
            Section 2.03(1), or (z) provided the HCN Repayment Conditions and
            the requirements of Section 2.05(3)(i) or (ii) are satisfied, the
            net proceeds of the issuance of Senior Unsecured Debt or
            Subordinated Debt; (vii) payments on account of Permitted Debt from
            the proceeds of any other Debt which is Refinancing Debt in respect
            of such Permitted Debt; (viii) payments on account of the principal
            amount of the HCN Notes referred to in clause (i) of the definition
            of HCN Notes from the net proceeds of an offering of equity
            securities of CanWest; and (ix) any payments or prepayments required
            or permitted to be made to the Administrative Agent or the Lenders
            under any other provisions of this Agreement".

      (iii) by amending the definition of "Senior Debt" by (a) inserting
            immediately after the word "Senior" the word Secured", (b) deleting
            the word " and immediately prior to clause (iii), and (c) inserting
            immediately after clause (iii) the words "; and (iv) the aggregate
            principal amount of any outstanding Senior Unsecured Debt".

      (iv)  by amending the definition of "Senior Leverage Ratio" by (a)
            inserting immediately before the word "Leverage" the word "Secured",
            and (b) inserting immediately before the word "Debt" the word
            "Secured.

      (v)   by the addition of the following new definitions:

            "HCN Repayment Conditions" means 00 the Borrower shall have repaid
            Accommodations Outstanding under the Term Credit Facilities and
            shall have permanently reduced the aggregate Commitment thereunder
            by an amount equal to or greater than Cdn.$700,000,000 (not
            including any amount from the permanent reduction of Accommodations
            Outstanding by

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            virtue of any repayment made pursuant to Section 2.04(2), 2.04(3) or
            2.04(4)), in each case subject to and in accordance with Section
            2.09 hereof, and (B) on a pro firma basis immediately after giving
            effect to (a) any Accommodation under the Revolving Credit Facility
            intended to be used for such purpose, if any, and (b) any such
            repayment or refinancing of the principal amount of any such HCN
            Notes and the Mirror Notes: (i) the unused availability under the
            Revolving Credit Facility is not less than $200,000,000; and (ii)
            the Senior Secured Leverage Ratio (calculated as at the end of the
            most recently completed Financial Quarter for the four Financial
            Quarters then ended) shall not exceed 3.5X and (iii) the ratio of
            EBITDA of the Global Group to Interest Expense of the Global Group
            (calculated as at the end of the most recently completed Financial
            Quarter for the four Financial Quarters then ended) shall not be
            less than (i) 1.754, if on or prior to May 31, 2004, or (ii)
            2.0:1,thereafter.

            "Senior Unsecured Debt" means, in respect of any Person, Debt of
            such Person which (a) has covenants, events of default and
            redemption, repurchase and modification provisions, in the
            aggregate, that are less favourable to the holder of such Debt than
            the covenants, events of default and redemption, repurchase and
            modification provisions of the Credit Documents, (b) is not
            guaranteed by any Person which is not a Global Group Entity, (c) has
            no required redemption provisions prior to, and matures, not less
            than one year after the latest Relevant Repayment Date, (6) is
            unsecured, and (e) is not Subordinated Debt.

3. Amendments to Section 2.03(1) of the Credit Agreement. Section 2.03(1) of the
Credit Agreement is amended effective as of this date by deleting the third
sentence thereof and inserting the following in its place:

            "Accommodations under the Revolving Credit Facility shall be
            available (a) to repay and refinance, or purchase, in whole or in
            part, the principal amount of the HCN Notes referred t o in clause
            (i) of the definition of HCN Notes and the Mirror Notes, and accrued
            and unpaid interest relating to such HCN Notes and Mirror Notes so
            repaid, refinanced or purchased if the HCN Repayment Conditions are
            satisfied and (b) to prepay Accommodations Outstanding under the
            Term Credit Facilities."

4. Amendment to Section 2.05 of the Credit Agreement. Section 2.05 of the Credit
Agreement is amended effective as of this date as follows:

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                                       4

      (i)   by amending Section 2.05(3) by inserting at the beginning thereof
            the number "(i)", and inserting at the end thereof the following new
            clause (ii):

            "(ii) An amount equal to the Net Proceeds of any Debt referred to in
            clause (xiii) of the definition of Permitted Debt created or
            incurred by CanWest or any other Global Group Entity, shall be
            prepaid by the Borrower within ten (10) Business Days of the date of
            issuance of such Debt and applied (i) firstly, rateably to the
            prepayment of the Accommodations Outstanding under the Term Credit
            Facilities; and (ii) secondly, to the permanent reduction of the
            Revolving Credit Commitment (and the Borrower shall repay the amount
            by which the Accommodations Outstanding under the Revolving Credit
            Facility after giving effect to such reduction exceed the Revolving
            Credit Commitment), in each case, subject to and in accordance with
            Section 2.09 hereof."

      (ii)  by amending Section 2.05(7) by deleting the phrase "not less than 10
            days" on or about the tenth line and replacing it with the phrase
            "not less than 3 Business Days".

5. Amendment to Section 8.03(1) of the Credit Agreement. Section 8.03(1) of the
Credit Agreement is amended effective as of this date as follows:

      (i)   by deleting clause (b) thereof and inserting the following in its
            place:

            "(b) Senior Secured Leverage Ratio. Maintain, during each Financial
            Quarter in each Financial Year commencing with the Financial Quarter
            ending November 30, 2000, a ratio of Senior Secured Debt to EBITDA
            for the four Financial Quarters then ended of the Global Group of
            not more than (i)5.011 for the Financial Quarters ending November
            30, 2000, February 28, 2001, May 31, 2001, August 31, 2001 and
            November 30, 2001; (ii) 4.7511 for the Financial Quarters ending
            February 28, 2002, May 31, 2002, August 31, 2002 and November 30,
            2002; (m) 4.5011 for the Financial Quarter ending February 28, 2003;
            (iv) 4,252 for the Financial Quarters ending May 31, 2003, August
            31, 2003 and November 30, 2003; and (v) 4.0011 for the Financial
            Quarter ending February 29, 2004 and each Financial Quarter
            thereafter."

      (ii)  by amending clause (c) thereof by inserting the following words at
            the end thereofl "; or (iv), provided the Borrower shall have repaid
            after March 1, 2003, Accommodations Outstanding

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                                      -5-

            under the Term Credit Facilities and shall have permanently reduced
            the aggregate Commitment thereunder by a n amount equal to or
            greater than Cdn.$255,000,000 (not including any amount from the
            permanent reduction of Accommodations Outstanding by virtue of any
            repayment made pursuant t o Section 2.04(2), 2.04(3) or 2.04(4)), in
            each case subject to and in accordance with Section 2.09 hereof,
            1.75:l for the Financial Quarters ending May 31, 2003, August 31,
            2003, November 30, 2003, February 29, 2004 and May 31, 2004, and
            2.03 for each Financial Quarter thereafter".

6. Condition Precedent. It is a condition precedent to the effectiveness of this
amending agreement that (a) the Borrower shall have paid to the Lenders an
amendment fee equal to 10 bps calculated on Accommodations Outstanding as of
March 13, 2003, and (b) the Borrower and the Guarantors shall have delivered a
confirmation of guarantees and security in form and substance reasonably
satisfactory to the Administrative Agent.

7. Reference to and Effect on the Credit Agreement. On and after this date, each
reference in the Credit Agreement to "this agreement" and each reference to the
Credit Agreement in the Credit Documents and any and all other agreements,
documents and instruments delivered by any of the Lenders, the Administrative
Agent, the Borrower, the Guarantor or any other Person shall mean and be a
reference to the Credit Agreement as amended by this amending agreement. Except
as specifically amended by this amending agreement, the Credit Agreement shall
remain in full force and effect and is hereby ratified and confirmed. This
amending agreement will not result in a novation, substitution, discharge or
extinguishment of any Credit Document.

8. No Waiver, etc. The execution, delivery and effectiveness of this amending
agreement shall not, except as expressly provided, operate as a waiver of any
right, power or remedy of the Administrative Agent or any of the Lenders under
any of the Credit Documents nor constitute a waiver of any provision of any of
the Credit Documents.

9. Governing Law. This amending agreement shall be governed by and interpreted
and enforced in accordance with the laws of the Province of Ontario and the laws
of Canada applicable therein.

10. Counterparts. This amending agreement may be executed in any number of
counterparts (including by way of facsimile) and all of such counterparts taken
together shall be deemed to constitute one and the same instrument.

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      IN WITNESS WHEREOF, the parties have caused this amending agreement to be
executed by their respective duly authorized officers as of the date first above
written.

                                     CANWEST MEDIA INC.,
                                     as Borrower

                                     Per:      /s/ illegible
                                               -----------------------------
                                               Authorized Signing Officer

                                     Per:      /s/ illegible
                                               -----------------------------
                                               Authorized Signing Officer


                                     CANWEST GLOBAL COMMUNICATIONS
                                     CORP.,
                                     as Guarantor

                                     Per:      /s/ illegible
                                               -----------------------------
                                               Authorized Signing Officer

                                     Per:      /s/ illegible
                                               -----------------------------
                                               Authorized Signing Officer


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                                     THE BANK OF NOVA SCOTIA,
                                     as Administrative Agent


                                     Per:      /s/ illegible
                                               -----------------------------
                                               Authorized Signing Officer

                                     Per:
                                               -----------------------------
                                               Authorized Signing Officer


                                     THE BANK OF NOVA SCOTIA,
                                     as agent for and on behalf of the
                                     Majority Lenders

                                     Per:      /s/ illegible
                                               -----------------------------
                                               Authorized Signing Officer

                                     Per:
                                               -----------------------------
                                               Authorized Signing Officer