<PAGE>
                                                                     EXHIBIT 4.5

                                    GUARANTEE

      THE OBLIGATIONS OF THE GUARANTORS TO THE HOLDERS OF NOTES PURSUANT TO THIS
GUARANTEE AND THE INDENTURE DATED AS OF APRIL 3, 2003, BY AND AMONG CANWEST
MEDIA INC. (THE "COMPANY"), THE GUARANTORS NAMED THEREIN AND THE TRUSTEE NAMED
THEREIN (THE "INDENTURE") ARE EXPRESSLY SET FORTH IN ARTICLE 11 OF THE
INDENTURE, AND REFERENCE IS HEREBY MADE TO SUCH INDENTURE FOR THE PRECISE TERMS
OF THIS GUARANTEE. THE TERMS OF THE INDENTURE, INCLUDING WITHOUT LIMITATION
ARTICLE 11, ARE INCORPORATED HEREIN BY REFERENCE.

      Each of the Guarantors hereby, jointly and severally, unconditionally
guarantees to each Noteholder, irrespective of the validity and enforceability
of the Indenture, the Notes or the obligations of the Company thereunder, that:
(a) the principal of and premium and interest on the Notes shall be promptly
paid in full when due, whether at the Maturity Date, by acceleration, redemption
or otherwise, and interest on the overdue principal of (and any premium) and
interest on the Notes, if any, if lawful, and all other obligations of the
Company to the Noteholders thereunder shall be promptly paid in full or
performed, all in accordance with the terms thereof; and (b) in case of any
extension of time of payment or renewal of any Notes or any of such other
obligations, that the same shall be promptly paid in full when due or performed
in accordance with the terms of the extension or renewal, whether at the
Maturity Date, by acceleration or otherwise. Failing payment when due of any
amount so guaranteed or any performance so guaranteed for whatever reason, the
Guarantors shall be jointly and severally obligated to pay the same immediately.
Each Guarantor hereby agrees that its obligations hereunder shall be
unconditional, irrespective of the validity, regularity or enforceability of the
Notes or the Indenture, the absence of any action to enforce the same, any
waiver or consent by any Noteholder with respect to any provisions thereof, the
recovery of any judgment against the Company, any action to enforce the same or
any other circumstance which might otherwise constitute a legal or equitable
discharge or defense of a Guarantor. Each Guarantor hereby waives diligence,
presentment, demand of payment, filing of claims with a court in the event of
insolvency or bankruptcy of the Company, any right to require a proceeding first
against the Company, protest, notice and all demands whatsoever and covenants
that, subject to Article 11 of the Indenture, this Guarantee shall not be
discharged except by complete performance of the obligations contained in the
Notes and the Indenture.

      If any Noteholder is required by any court or otherwise to return to the
Company or Guarantors, or any custodian, trustee, liquidator or other similar
official acting in relation to either the Company or Guarantors, any amount paid
to such Noteholder, this Guarantee, to the extent theretofore discharged, shall
be reinstated in full force and effect. Each Guarantor agrees that it shall not
be entitled to any right of subrogation in relation to the


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                                      -2-



Noteholders in respect of any obligations guaranteed hereby until such time as
the Indebtedness of the Company evidenced by the Note shall have been paid in
full. Each Guarantor further agrees that, as between the Guarantors, on the one
hand, and the Noteholders, on the other hand, (a) the Maturity Date of the
obligations guaranteed hereby may be accelerated as provided in Section 6.02 of
the Indenture for the purposes of this Guarantee, notwithstanding any stay,
injunction or other prohibition preventing such acceleration in respect of the
obligations Guaranteed hereby, and (b) in the event of any declaration of
acceleration of such obligations as provided in Section 6.02 of the Indenture,
such obligations (whether or not due and payable) shall forthwith become due and
payable by the Guarantors for the purpose of this Guarantee. The Guarantors
shall have the right to seek contribution from any non-paying Guarantor so long
as the exercise of such right does not impair the rights of the Noteholders
under the Guarantees.

      The obligations of each Guarantor under this Guarantee are junior and
subordinated to the Senior Indebtedness of such Guarantor to the extent in the
manner provided for in Article 11 of the Indenture.

      Each Guarantor, and by its acceptance of Notes, each Noteholder, hereby
confirms that it is the intention of all such parties that this Guarantee not
constitute a fraudulent transfer or conveyance for purposes of any Bankruptcy
Law, the Uniform Fraudulent Conveyance Act, the Uniform Fraudulent Transfer Act
or any similar federal, state, provincial or territorial law to the extent
applicable to any Guarantee. To effectuate the foregoing intention, the
Noteholders and the Guarantors hereby irrevocably agree that the obligations of
each Guarantor under this Guarantee and Article 11 of the Indenture shall be
limited to the maximum amount as will, after giving effect to such maximum
amount and all other contingent and fixed liabilities of such Guarantor that are
relevant under such laws, and after giving effect to any collections from,
rights to receive contribution from or payments made by or on behalf of any
other Guarantor in respect of the obligations of such other Guarantor under
Article 11 of the Indenture, result in the obligations of such Guarantor under
this Guarantee not constituting a fraudulent transfer or conveyance.

      This is a continuing Guarantee and shall remain in full force and effect
and shall be binding upon the undersigned Guarantors and their respective
successors and assigns to the extent set forth in the Indenture until full and
final payment of all of the Company's obligations under the Notes and the
Indenture and shall inure to the benefit of the Noteholders and their successors
and assigns and, in the event of any transfer or assignment of rights by any
Noteholder, the rights and privileges herein conferred upon that party shall
automatically extend to and be vested in such transferee or assignee, all
subject to the terms and conditions hereof and of Article 11 of the Indenture.
Notwithstanding the foregoing, any Guarantor that satisfies the provisions of
Section 11.05 of the Indenture shall be released of its obligations hereunder.



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                                      -3-



      THIS GUARANTEE SHALL BE CONSTRUED AND ENFORCED IN ACCORDANCE WITH, AND THE
RIGHTS OF THE PARTIES SHALL BE GOVERNED BY, THE LAW OF THE STATE OF NEW YORK,
EXCLUDING CHOICE-OF-LAW PRINCIPLES OF THE LAW OF THE STATE OF NEW YORK THAT
WOULD REQUIRE THE APPLICATION OF THE LAWS OF ANY JURISDICTION OTHER THAN THE
STATE OF NEW YORK.

      Capitalized terms used herein have the same respective meanings given in
the Indenture unless otherwise indicated.


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                                      -4-




      IN WITNESS WHEREOF, each of the Guarantors has caused this Guarantee to be
signed by a duly authorized officer.

Dated: April 3, 2003

<TABLE>
<S>                                                 <C>

                                                    2846551 CANADA INC. (CBCA)

                                                    3919056 CANADA LIMITED (CBCA)

                                                    APPLE BOX PRODUCTIONS SUB INC. (CBCA)

                                                    BCTV HOLDINGS INC. (CBCA)

                                                    CALGARY HERALD GROUP INC.

                                                    CANWEST - MONTREAL R.P. HOLDINGS INC.

                                                    CANWEST - WINDSOR R.P. HOLDINGS INC.

                                                    CANWEST FINANCE INC./FINANCIERE CANWEST INC. (QUEBEC)

                                                    CANWEST GLOBAL BROADCASTING INC./RADIODIFFUSION CANWEST GLOBAL INC. (QUEBEC)

                                                    CANWEST INTERACTIVE INC.

                                                    CANWEST INTERNATIONAL COMMUNICATIONS INC. (BARBADOS)

                                                    CANWEST INTERNATIONAL MANAGEMENT INC. (BARBADOS)

                                                    CANWEST IRISH HOLDINGS (BARBADOS) INC. (BARBADOS)

                                                    CANWEST MEDIA SALES LIMITED (CBCA)
</TABLE>

<PAGE>
                                      -5-


<TABLE>
<S>                                                 <C>

                                                    CANWEST NZ RADIO HOLDINGS LIMITED (NEW ZEALAND)

                                                    CANWEST PUBLICATIONS INC.

                                                    CGS DEBENTURE HOLDING (NETHERLANDS) B.V. (NETHERLANDS)

                                                    CGS INTERNATIONAL HOLDINGS (NETHERLANDS) B.V.

                                                    CGS NZ RADIO SHAREHOLDING (NETHERLANDS) B.V.

                                                    CGS NZ TV SHAREHOLDING (NETHERLANDS) B.V.

                                                    CGS SHAREHOLDING (NETHERLANDS) B.V. (NETHERLANDS)

                                                    CHBC HOLDINGS INC. (CBCA)

                                                    CHEK HOLDINGS INC. (CBCA)

                                                    CLARINET MUSIC INC. (ONTARIO)

                                                    EDMONTON JOURNAL GROUP INC.

                                                    FOX SPORTS WORLD CANADA HOLDCO INC. (CBCA)

                                                    GLOBAL CENTRE INC. (ONTARIO)

                                                    GLOBAL COMMUNICATION LIMITED (MANITOBA)

                                                    GLOBAL TELEVISION CENTRE LTD. (CBCA)

                                                    GLOBAL TELEVISION NETWORK INC. (CBCA)
</TABLE>

<PAGE>
                                      -6-
<TABLE>
<S>                                                <C>


                                                    GLOBAL TELEVISION SPECIALTY NETWORKS INC. (CBCA)

                                                    LONESTAR HOLDCO INC. (CBCA)

                                                    LOWER MAINLAND PUBLISHING GROUP INC.

                                                    MONTREAL GAZETTE GROUP INC.

                                                    MULTISOUND PUBLISHERS LTD. (CBCA)

                                                    NANAIMO DAILY NEWS GROUP INC.

                                                    ONTV HOLDINGS INC. (CBCA)

                                                    OTTAWA CITIZEN GROUP INC.

                                                    PACIFIC NEWSPAPER GROUP INC.

                                                    PORT ALBERNI TIMES GROUP INC.

                                                    REACHCANADA CONTACT CENTRE LIMITED (CBCA)

                                                    REGINA LEADER POST GROUP INC.

                                                    RETROVISTA HOLDCO INC. (CBCA)

                                                    SASKATOON STARPHOENIX GROUP INC.

                                                    SOUTHAM DIGITAL INC.

                                                    STUDIO POST & TRANSFER SUB INC. (CBCA)

                                                    TV3 NETWORK SERVICES LIMITED (NEW ZEALAND)

                                                    TV4 NETWORK LIMITED (NEW ZEALAND)
</TABLE>

<PAGE>
                                      -7-

<TABLE>
<S>                                                 <C>
                                                    VANCOUVER ISLAND NEWSPAPER GROUP INC. (CBCA)

                                                    VICTORIA TIMES COLONIST GROUP INC.

                                                    WESTERN COMMUNICATION INC. (CBCA)

                                                    WIC MOBILE TV INC. (CBCA)

                                                    WIC TELEVISION PRODUCTION SUB INC. (CBCA)

                                                    WINDSOR STAR GROUP INC.

                                                    XTREME SPORTS HOLDCO INC. (CBCA)

</TABLE>

                                        By:   /s/ JOHN MAGUIRE
                                              ----------------------------------
                                              Name:  John Maguire
                                              Title: Authorized Signing Officer