<PAGE>

                                                                   EXHIBIT 10.11

                                WARRANT AGREEMENT

THIS WARRANT AGREEMENT (the "AGREEMENT") has been entered into as of the 30th
day of April, 2004, by and among Microcell Telecommunications Inc.
("MICROCELL"), a corporation existing under the laws of Canada, and COM Canada,
LLC, a Washington limited liability company ("COM Canada ");

WHEREAS on or about the 24th day of March, 2004, Microcell filed a final
prospectus in Canada, whereby it offered to the holders of record of its shares
on the record date, rights to subscribe for Class B Non-Voting Shares (the
"CLASS B SHARES") in its share capital, the whole as further set out in the
prospectus (the "RIGHTS OFFERING");

WHEREAS, in connection with the Rights Offering, as of the 26th day of February,
2004, Microcell and COM Canada entered into a standby purchase agreement (the
"STANDBY AGREEMENT") whereby, inter alia, COM Canada agreed to purchase all of
the Class B Shares that were offered but not otherwise purchased pursuant to the
Rights Offering as well as the Basic Shares (as such term is defined in the
Standby Agreement) which Microcell agreed to issue to COM Canada;

WHEREAS, in accordance with the terms and conditions set out in the Standby
Agreement, Microcell had also agreed to issue COM Canada warrants to acquire
Class B Shares;

NOW, THEREFORE, in consideration of the mutual covenants contained herein and
other good and valuable consideration, the receipt and sufficiency of which are
hereby acknowledged, the parties hereto have agreed as set forth below.

                                    ARTICLE I
                              ISSUANCE of WARRANTS

1.1   Microcell hereby issues to COM Canada which hereby accepts, subject to the
      terms and conditions hereinafter set forth, 3,977,272 warrants, each such
      warrant entitling COM Canada to purchase one Class B Share at an exercise
      price of $22.00 per Class B Share (the "EXERCISE PRICE"), all subject to
      adjustment as provided in Article IV hereof.

                                   ARTICLE II
                                  WARRANT TERM

2.1   The warrants issued hereunder shall be exercisable as follows:

      (a)   from April 30, 2005 until 4:30 p.m. (Montreal time) on October 31,
            2005 (the "1ST VESTING PERIOD"), 1,325,757 warrants may be exercised
            by COM Canada;

<PAGE>
                                                                              2.

      (b)   from April 30, 2005 until 4:30 p.m. (Montreal time) on October 31,
            2006 (the "2ND VESTING PERIOD"), 1,325,757 warrants may be exercised
            by COM Canada; and

      (c)   from December 31, 2005 until 4:30 p.m. (Montreal time) on April 30,
            2008 (the "3RD VESTING PERIOD"), 1,325,758 warrants may be exercised
            by COM Canada.

            (the 1st Vesting Period, the 2nd Vesting Period and the 3rd Vesting
            Period being hereinafter collectively referred to as the "VESTING
            PERIOD").

2.2   During the applicable Vesting Period, COM Canada may, from time to time in
      minimum installments of at least 250,000 warrants per installment,
      exercise up to the aggregate number of warrants that have vested during
      such Vesting Period by giving notice in writing to Microcell in accordance
      with Section 3.1 hereof.

2.3   Notwithstanding any other provision of this Agreement (but in addition to
      the provisions hereof at Article IV dealing with Fundamental
      Transactions), in the event (i) a Fundamental Transaction occurs, or in
      the event an offer to purchase the Class B Shares or any part thereof
      shall be made to all holders of Class B Shares, or if a transaction or
      series of transactions occur in which a person or group of persons (acting
      jointly or otherwise in concert), and in either case other than COM
      Canada, acquires beneficial ownership of more than 50% of the aggregate
      voting power and more than 30% of the issued and outstanding equity
      securities of Microcell, and (ii) COM Canada does not consent in writing
      to such transaction, Microcell shall provide prompt written notice thereof
      to COM Canada and COM Canada shall have the right to immediately exercise
      all vested and unvested warrants (which, for greater certainty, shall not
      include any warrants that had already lapsed pursuant to Section 2.4 or
      otherwise of this Agreement) by giving written notice thereof to
      Microcell; provided however that (A) any such notice of exercise shall
      only become effective in the event that such transaction is then
      consummated, and (B) in the event that such transaction is not
      consummated, then such notice shall be deemed never to have been given and
      the warrants shall continue in effect, unamended hereby.

2.4   At the expiry of each Vesting Period, the warrants that had vested during
      such Vesting Period but that had not been exercised by COM Canada shall
      lapse, have no value and shall no longer be exercisable.

                                   ARTICLE III
                              EXERCISE OF WARRANTS

3.1   The warrants issued under this Agreement shall be exercisable (from time
      to time and in accordance with the limits set out at Section 2.1 above) by
      COM Canada giving written notice to Microcell, which notice shall specify
      the number of warrants that are being exercised for the corresponding
      number of Class B Shares (the "ACQUIRED SHARES").

3.2   Within 5 days of receipt of COM Canada's written notice of exercise,
      Microcell shall, at its option, either:

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                                                                              3.

      (a)   provide written notice to COM Canada that it will deliver a share
            certificate to, and registered in the name of, COM Canada,
            representing, in the aggregate, the number of Acquired Shares (it
            being understood that the time and location of such delivery will be
            determined by Microcell and COM Canada in good faith, and that
            simultaneous with the delivery of such share certificate, COM Canada
            shall be obligated to pay (by cash or certified cheque) the
            aggregate Exercise Price for the Acquired Shares to Microcell); or

      (b)   pay to COM Canada (by cash, wire transfer or certified cheque) an
            amount equal to the remainder of (A) the aggregate Fair Market Value
            of the Acquired Shares, less (B) the aggregate Exercise Price of the
            Acquired Shares; or

      (c)   deliver to COM Canada a share certificate registered in the name of
            COM Canada, representing the number of Class B Shares that have a
            Fair Market Value equal to the remainder of (A) the aggregate Fair
            Market Value of the Acquired Shares, less (B) the aggregate Exercise
            Price of the Acquired Shares (it being understood that, for the
            purposes of the foregoing, Microcell shall not be required to issue
            fractional shares to COM Canada and instead may pay any balance owed
            to COM Canada in cash).

      provided that should COM Canada exercise that portion of the warrants that
      are exercisable by it during the 3rd Vesting Period, COM Canada may in the
      notice delivered to Microcell pursuant to Section 3.1 hereof, instruct
      Microcell that the exercise of such portion of the warrants shall be
      satisfied by COM Canada receiving from Microcell, at Microcell's option,
      only the consideration that is set forth in Section 3.2(b) or 3.2(c).

      For the purposes of the foregoing, "FAIR MARKET VALUE" shall mean the
      simple average of the closing price of the Class B Shares on the Toronto
      Stock Exchange, such simple average to be calculated on the basis of the
      closing price of the Class B Shares on the Toronto Stock Exchange on each
      of the trading days on which there was such a closing price during the ten
      (10) day period ending on the day that precedes the day on which COM
      Canada gives written notice of its exercise to Microcell.

3.3   COM Canada acknowledges that Microcell's election pursuant to Section 3.2
      shall be made by Microcell in its sole discretion, and that the
      fulfillment by Microcell of its obligations in accordance with such
      election, will constitute full and satisfactory consideration to COM
      Canada for the number of Acquired Shares in respect of which COM Canada
      has exercised its warrants.

3.4   COM Canada acknowledges that the Class B Shares, if any, issued to it by
      Microcell pursuant to this Agreement may be subject to resale restrictions
      or a hold period under applicable securities laws and that it is the sole
      responsibility of COM Canada to ensure that the resale, if any, of such
      shares is completed in accordance with the requirements of applicable
      securities laws. Each share certificate issued to COM Canada under this
      Agreement may include a restrictive legend evidencing such resale
      restriction and/or hold period that is, in the reasonable opinion of
      counsel, required under applicable law.

<PAGE>

                                                                              4.

                                   ARTICLE IV
                                  ADJUSTMENTS

4.1   The number of warrants issued to COM Canada hereunder will be adjusted
      from time to time in the events and in the manner provided in, and in
      accordance with the provisions of this Article IV, and for such purposes
      and as used in this Article IV, (A) "ADJUSTMENT PERIOD" means the period
      commencing immediately after April 30, 2004 and ending at 4:30 p.m.
      (Montreal time) on April 30, 2008 (or such earlier time as (i) this
      Agreement has been terminated, or (ii) all of the warrants issued
      hereunder have been exercised by COM Canada, or (iii) all of the warrants
      issued hereunder have lapsed, been cancelled or have otherwise been
      rendered null (the "EXPIRY TIME"), and (B) "SHARE NUMBER" means the number
      of Class B Shares that are issuable upon the exercise of a warrant, which
      number, subject to adjustment pursuant to this Article IV, will be one
      Class B Share per warrant.

4.2   The Share Number in effect at any date will be subject to adjustment from
      time to time as follows:

      (a)   If and whenever at any time during the Adjustment Period, Microcell
            shall:

            (i)   subdivide or redivide the outstanding Class B Shares into a
                  greater number of Class B Shares; or

            (ii)  consolidate, combine or reduce the outstanding Class B Shares
                  into a lesser number of Class B Shares; or

            (iii) issue Class B Shares to all or substantially all of the
                  holders of Class B Shares by way of a stock dividend or other
                  distribution,

            then, in each such event, the Share Number will, on the effective
            date of or the record date for such event, be adjusted by
            multiplying the Share Number in effect immediately prior to such
            date by a fraction.

            (iv)  the numerator of which shall be the total number of Class B
                  Shares outstanding on such date after giving effect to such
                  event; and

            (v)   the denominator of which shall be the total number of Class B
                  Shares outstanding on such date before giving effect to such
                  event.

            Such adjustment will be made successively whenever any such event
            shall occur. Any such issue of Class B Shares by way of a stock
            dividend or other distribution shall be deemed to have been made on
            the record date for such stock dividend or other distribution for
            the purpose of calculating the number of outstanding Class B Shares
            under paragraph 4.2(b) and paragraph 4.2(c).

      (b)   If and whenever, at any time during the Adjustment Period, Microcell
            shall fix a record date for the issuance of rights, options or
            warrants to all or substantially all of the holders of Class B
            Shares entitling the holders thereof, within a period

<PAGE>

                                                                              5.

            expiring not more than 50 days after the record date for such issue,
            to subscribe for or purchase Class B Shares (or securities
            convertible into or exchangeable for Class B Shares) (the "SHORT
            TERM WARRANTS") and such Short Term Warrants are exercisable at a
            price per share (or have a conversion or exchange price per share)
            less than 95% of the "CURRENT MARKET PRICE" (and for the purposes
            hereof, "CURRENT MARKET PRICE" shall mean the closing trading prices
            per share of Class B Shares on any particular date (and if such date
            is not a business day, the last business day before such date)) on
            the earlier of the day that is three business days prior to the
            record date and the date on which Microcell announces its intention
            to make such issuance, then, in each such case, the Share Number
            will be adjusted immediately after such record date by multiplying
            the Share Number in effect on such record date by a fraction:

            (i)   the numerator of which shall be the total number of Class B
                  Shares outstanding on such record date plus the total number
                  of additional Class B Shares so offered for subscription or
                  purchase (or into or for which the convertible or exchangeable
                  securities so offered are convertible or exchangeable); and

            (ii)  the denominator of which shall be the aggregate of (A) the
                  number of Class B Shares outstanding on such record date and
                  (B) a number determined by dividing the aggregate subscription
                  or purchase price of the total number of additional Class B
                  Shares so offered for subscription or purchase (or the
                  aggregate conversion or exchange price of the convertible or
                  exchangeable securities so offered) by the Current Market
                  Price as of the applicable record date.

            Any Class B Shares owned by or held for the account of Microcell or
            any of its subsidiaries shall be deemed not to be outstanding for
            the purpose of any such computation. Such adjustments will be made
            successively whenever such a record date is fixed. To the extent
            that any such rights, options or warrants are not so issued or any
            such rights, options or warrants are not exercised prior to the
            expiration thereof, the Share Number will then be readjusted to the
            Share Number which would then be in effect if such record date had
            not been fixed or to the Share Number which would then be in effect
            based upon the number of Class B Shares (or securities convertible
            into or exchangeable for Class B Shares) actually issued upon the
            exercise of such rights, options or warrants, as the case may be.

      (c)   If and whenever at any time during the Adjustment Period, Microcell
            shall fix a record date for the making of a distribution to all or
            substantially all of the holders of Class B Shares of:

            (i)   shares of any class other than Class B Shares, whether of
                  Microcell or any other corporation;

            (ii)  rights, options or warrants other than Short Term Warrants;

<PAGE>

                                                                              6.

            (iii) evidence of indebtedness; or

            (iv)  cash, securities or other property or assets;

            then, in each such case, the Share Number will be adjusted
            immediately after such record date by multiplying the Share Number
            in effect on such record date by a fraction:

            (v)   the numerator of which shall be the total number of Class B
                  Shares outstanding on such record date multiplied by the
                  Current Market Price on such record date; and

            (vi)  the denominator of which shall be (A) the product of the
                  number of Class B Shares outstanding on such record date and
                  the Current Market Price on the earlier of such record date
                  and the date on which Microcell announces its intention to
                  make such distribution reduced by (B) the aggregate fair
                  market value (as determined by the directors in good faith and
                  acting reasonably at the time such distribution is authorized)
                  of such shares or rights, options or warrants or evidences of
                  indebtedness or cash, securities or other property or assets
                  to be so distributed.

            Any Class B Shares owned by or held for the account of Microcell or
            any of its subsidiaries shall be deemed not to be outstanding for
            the purpose of any such computation. Such adjustments will be made
            successively whenever such a record date is fixed. To the extent
            that such distribution is not so made or to the extent that any such
            rights, options or warrants so distributed are not exercised prior
            to the expiration thereof, the Share Number will then be readjusted
            to the Share Number which would then be in effect if such record
            date had not been fixed or to the Share Number which would then be
            in effect based upon such shares or rights, options or warrants or
            evidences of indebtedness or cash, securities or other property or
            assets actually distributed or based upon the number or amount of
            securities or the property or assets actually issued or distributed
            upon the exercise of such rights, options or warrants, as the case
            may be.

      (d)   In the absence of a resolution of the directors of Microcell fixing
            a record date for any event referred to in this Article IV,
            Microcell shall be deemed to have fixed as the record date therefore
            the earlier of the date on which holders of record of Class B Shares
            are determined for the purpose of participating in such event and
            the date on which such event becomes effective.

      (e)   If whenever at any time after the Effective Date and ending at the
            Expiry Time, any of the events referred to in Section 4.2(a), (b) or
            (c) occurs and if such event results in an adjustment to the Share
            Number, the Exercise Price shall be adjusted contemporaneously with
            each such adjustment of the Share Number (including, for greater
            certainty, any readjustment of the Share Number if and to the extent
            that a distribution or issuance of securities or exercise of rights,
            warrants or options pursuant to Section 4.2(b) or (c) is not
            completed) by multiplying the

<PAGE>

                                                                              7.

            Exercise Price in effect immediately prior to the occurrence of such
            event by a fraction:

            (i)   the numerator of which shall be the number of Class B Shares
                  outstanding immediately before giving effect to such event;
                  and

            (ii)  the denominator of which shall be the number of Class B Shares
                  outstanding immediately after giving effect to such event;

            provided that, in addition, in any such event contemplated by
            Section 4.2(c) not involving the issuance of Class B Shares, the
            Exercise Price shall be divided by the fraction contemplated in
            subparagraphs (v) and (vi) therein, it being understood that
            adjustments in the Share Number and in the Exercise Price in any
            such event should not result in any duplication in their effects nor
            in the increase of the Exercise Price in effect immediately prior to
            the relevant record date.

4.3

      (a)   If and whenever at any time during the Adjustment Period, there is
            (i) any reclassification of the Class B Shares at any time
            outstanding or any change of the Class B Shares into other shares,
            securities or property of Microcell, or any other capital
            reorganization of Microcell of similar effect (other than as
            described in Section 4.2), (ii) any amalgamation, arrangement,
            merger or other form of business combination of Microcell with or
            into any other corporation resulting in any reclassification of the
            outstanding Class B Shares or change of the Class B Shares into
            other shares, securities or property of Microcell or such other
            corporation, or (iii) any sale, lease, exchange or transfer of all
            or substantially all of the undertaking or assets of Microcell and/
            or the subsidiaries of Microcell to another corporation or entity
            not wholly-owned by Microcell (each of the transactions contemplated
            in (i), (ii) and (iii), hereinafter, a "FUNDAMENTAL TRANSACTION"),
            then, in each such event, COM Canada will be entitled to receive,
            and shall accept, in lieu of the number of Class B Shares to which
            COM Canada was theretofore entitled upon the exercise of warrants,
            the kind and number or amount of shares or other securities or
            property which COM Canada would have been entitled to receive as a
            result of the Fundamental Transaction if, on the effective date
            thereof, COM Canada had been the registered holder of the number of
            Class B Shares to which COM Canada was theretofore entitled upon
            such exercise.

      (b)   If and whenever at any time during the Adjustment Period, there is a
            Fundamental Transaction which provides for holders of the
            outstanding Class B Shares to receive consideration solely in the
            form of cash, COM Canada shall be deemed (i) where such cash
            consideration is, on a per Class B Share basis, in an amount greater
            than the Exercise Price, to exercise its warrants in full (but
            solely to the extent such warrants had not been previously exercised
            and to the extent that such warrants then remained vestable and
            exercisable) and COM Canada shall be entitled to receive, upon such
            deemed exercise, the cash consideration it

<PAGE>

                                                                              8.

            would have been entitled to receive had such exercise of the
            warrants taken place immediately prior to such Fundamental
            Transaction, less the Exercise Price thereof or (ii) where the cash
            consideration is, on a per Class B Share basis, equal to or less
            than the Exercise Price, to surrender its warrants, without payment
            of any consideration. Following such deemed exercise, all warrants
            shall be cancelled and shall be of no further value or effect.

            If necessary as a result of any Fundamental Transaction, appropriate
            adjustments will be made in the application of the provisions set
            forth in this Article IV with respect to the rights and interests
            thereafter of COM Canada to the end that the provisions set forth in
            this Article IV will thereafter correspondingly be made applicable
            as nearly as may reasonably be in relation to any shares or other
            securities or property thereafter deliverable upon the exercise of
            the warrants. Any such adjustments will be made by and set forth in
            an agreement supplemental hereto approved by Microcell and by COM
            Canada (both parties acting reasonably) and shall for all purposes
            be conclusively deemed to be an appropriate adjustment.

4.4   In any case in which this Article IV shall require that an adjustment
      shall become effective immediately after a record date for or an effective
      date of an event referred to herein, Microcell may defer, until the
      occurrence and consummation of such event, issuing to COM Canada the
      additional Class B Shares or other shares, securities or property issuable
      upon such exercise by reason of the adjustment required by such event,
      provided, however, that Microcell will deliver to COM Canada an
      appropriate instrument evidencing COM Canada's right to receive such
      additional Class B Shares or other shares, securities or property upon the
      occurrence and consummation of such event and the right to receive any
      dividend or other distribution in respect of such additional Class B
      Shares or other shares, securities or property declared in favour of the
      holders of record of Class B Shares or of such other shares, securities or
      property on or after the date of the exercise of the warrants or such
      later date as such holder would, but for the provisions of this
      subsection, have become the holder of record of such additional Class B
      Shares or of such other shares, securities or property pursuant hereto.

4.5   The adjustments provided for in this Article IV are cumulative, shall, in
      the case of any adjustment to the Share Number, be computed to the nearest
      one one-hundredth of a Class B Share and will apply (without duplication)
      to successive subdivisions, consolidations, distributions, issuances or
      other events resulting in any adjustment under the provisions of this
      Article IV, provided that, notwithstanding any other provision of this
      Article IV, no adjustment of the Share Number will be required (i) unless
      such adjustment would require an increase or decrease of at least 1% in
      the Share Number then in effect (provided, however, that any adjustment
      which by reason of this subsection is not required to be made will be
      carried forward and taken into account in any subsequent adjustment), (ii)
      if, in respect of any event described in this Section (other than the
      events referred to in Section 4.2(a)(i), Section 4.2(a)(ii) and Section
      4.3), COM Canada is entitled to participate in such event, or is entitled
      to participate within 45 days in a comparable event, on the same terms,
      mutatis mutandis as if the warrants had been exercised prior to or on the
      effective date of or record date for such event, (iii) in respect of any
      Class B Shares issuable or issued pursuant to any stock

<PAGE>

                                                                              9.

      option or stock purchase plan in force from time to time for directors,
      officers or employees of Microcell or of any of its subsidiaries or
      pursuant to the outstanding warrants of Microcell (which, for greater
      certainty, shall not include the warrants issued to COM Canada hereunder),
      (iv) in respect of any Class B Shares issued on the exercise of any other
      stock options issued by Microcell and outstanding on the date hereof, or
      (v) in respect of Class B Shares issued on the conversion into Class B
      Shares of preferred shares in the capital of Microcell outstanding on the
      date hereof.

4.6   In the event of any question arising with respect to the adjustments
      provided for in this Article IV, such questions shall be conclusively
      determined by Microcell's external auditors or, at COM Canada's request,
      by such firm of chartered accountants as is appointed by Microcell and is
      reasonably acceptable to COM Canada. Such accountants shall have access to
      all necessary records of Microcell and such determination shall be binding
      upon Microcell and COM Canada. If any such determination is made,
      Microcell shall forthwith deliver a certificate to COM Canada describing
      such determination.

4.7   If and whenever at any time during the Adjustment Period, Microcell shall
      take any action affecting or relating to the Class B Shares, other than
      any action described in this Article IV, which in the opinion of the board
      of directors of Microcell, acting reasonably, would prejudicially affect
      the rights of COM Canada, the Share Number and Exercise Price will be
      adjusted by the board of directors of Microcell in such manner, if any,
      and at such time, as the board of directors of Microcell may determine to
      be equitable in the circumstances.

4.8   As a condition precedent to the taking of any action which would require
      an adjustment pursuant to the foregoing provisions of this Article IV,
      Microcell will take any action which may, in the opinion of counsel to
      Microcell, be necessary in order that Microcell, or any successor to
      Microcell or successor to the undertaking or assets of Microcell, will be
      obligated to and may validly and legally issue all of the Class B Shares
      or other shares, securities or property which COM Canada would be entitled
      to receive on the exercise of its warrants in accordance with the
      provisions hereof.

4.9   As soon as possible after the effective date of or record date for any
      event referred to in this Article IV that requires or might require an
      adjustment in any of the rights under the warrants issued to COM Canada
      hereunder, Microcell will give notice to COM Canada of the particulars of
      such event and, to the extent determinable, any adjustment required. Such
      notice need only set forth such particulars as have been determined at the
      date such notice is given. If any adjustment for which such notice is
      given is not then determinable, promptly after such adjustment is
      determinable Microcell will file with COM Canada a certificate of
      Microcell showing the computation of such adjustment.

4.10  After any adjustment pursuant to this Article IV, the term "CLASS B
      SHARES" where used in this Agreement shall be interpreted to mean
      securities of any class or classes which, as a result of such adjustment
      and all prior adjustments pursuant to this Article IV, COM Canada is
      entitled to receive upon the exercise of its warrants, and the number of
      Class B Shares indicated in any exercise made pursuant to the warrants,
      shall be interpreted to mean the number of securities and other property
      and assets which, as a result of such

<PAGE>

                                                                             10.

      adjustment and all prior adjustments pursuant to this Article IV, COM
      Canada is entitled to receive upon the exercise of the warrants.

4.11  Any adjustments referred to in this Article IV are subject to confirmation
      by the Toronto Stock Exchange and any issue of additional shares as a
      result thereof shall be completed in accordance with all applicable
      Toronto Stock Exchange rules and policies.

                                    ARTICLE V
                           ASSIGNMENT AND ENCUMBRANCE

5.1   Unless otherwise agreed to in writing by Microcell, the warrants issued
      hereunder are personal to COM Canada and shall not be assignable or
      transferable by COM Canada, whether voluntarily or by operation of law,
      and whether directly or indirectly (including, for greater certainty, and
      without limitation, by way of a monetization or similar transaction).
      Notwithstanding the foregoing, COM Canada may, in a transfer that is made
      pursuant to an exemption from the registration requirements of, or in a
      transaction that is not subject to the Securities Act and any state
      securities or "blue sky" laws, assign or transfer the warrants to an
      affiliate (as the term affiliate is defined at Section 9 of the Securities
      Act (Quebec)), provided that COM Canada shall give five (5) days prior
      written notice of the assignment or transfer to Microcell and such written
      notice shall contain a representation from COM Canada that the transferee
      or assignee is an affiliate of COM Canada (as the term affiliate is
      defined at Section 9 of the Securities Act (Quebec)), and provided that
      such affiliate remains an affiliate at all times, failing which the
      warrants shall lapse, have no value and shall no longer be exercisable,
      unless such warrants are promptly transferred back to COM Canada.

5.2   The warrants issued hereunder shall not be pledged, hypothecated, charged
      or otherwise encumbered by COM Canada. Notwithstanding the foregoing, the
      warrants may be pledged by COM Canada in order to guarantee its
      obligations under a loan, credit or other bona fide financing agreement
      that has been entered into with a recognized financial institution,
      provided that such financial institution (and/or any of its affiliates) is
      not and is not an affiliate of a telecommunications company operating in
      Canada or the United States.

5.3   Notwithstanding Section 5.1 and Section 5.2 above beginning on December
      31, 2005, that portion of the warrants that may be exercised by COM Canada
      during the 2nd Vesting Period and the 3rd Vesting Period (as well as such
      portion of the underlying Class B Shares) shall be assignable,
      transferable, pledgeable, hypothecable and/or chargeable by COM Canada, so
      long as at least 250,000 of such warrants (as well as such portion of the
      underlying Class B Shares) are so assigned, transferred, pledged,
      hypothecated or charged to or in favour of the same third party and so
      long as such third party signs an undertaking satisfactory to Microcell
      (acting reasonably) that such third party is bound by and will respect the
      terms of this Agreement in respect of the warrants acquired by it and that
      any such assignment, transfer, pledge, hypothec or charge is made pursuant
      to an exemption from the registration requirements of, or in a transaction
      not subject to, the Securities Act and any state securities or "blue sky"
      laws.

<PAGE>

                                                                             11.

                                   ARTICLE VI
                                     NOTICE

6.1   Any notice or other communication required or permitted to be given
      hereunder shall be in writing and shall be personally delivered or sent by
      facsimile transmission as set forth below, or to such other address,
      facsimile number or person as may be designated by notice.

                         (a) In the case of Microcell:

                             Microcell Telecommunications Inc.
                             800 de La Gauchetiere St. West
                             Suite 400
                             Montreal, QC
                             H5A 1K3

                             Att: Chief Financial Officer
                             Fax: (514) 846-6959

                         (b) In the case of COM Canada:

                             COM Canada, LLC
                             2300 Carillon Point
                             Kirkland, Washington 98033

                             Att: Mr. Brian Marcinek
                             Fax:(425) 828-8061

6.2   Notice shall be deemed to be given on the day of actual delivery or the
      day of facsimile transmission, as the case may be, or if not a business
      day, on the next business day.

                                   ARTICLE VII
                                  MISCELLANEOUS

7.1   The division of this Agreement into articles, sections, paragraphs and
      clauses and the provision of headings are for the convenience of reference
      only and shall not affect the construction or interpretation of this
      Agreement. The terms "this agreement", "hereof", "hereunder" and similar
      expressions refer to this Agreement as a whole and not to any particular
      article, section, paragraph, clause or other portion hereof and include
      any agreement or instrument supplemental or ancillary hereto. Unless
      something in the subject matter or context is inconsistent therewith,
      references herein to articles, sections, paragraphs or clauses are to
      articles, sections, paragraphs or clauses of this Agreement.

7.2   Words importing the singular number only shall include the plural and vice
      versa, words importing the masculine gender shall include the feminine and
      neuter genders and vice versa and words importing persons shall include
      individuals, partnerships, trusts, corporations, governments and
      governmental authorities and vice versa.

<PAGE>

                                                                             12.

7.3   Unless otherwise specifically stated, all references to dollars and cents
      in this Agreement are to the lawful currency of Canada.

7.4   This Agreement shall be governed by, interpreted and enforced in
      accordance with the laws of the Province of Quebec and the federal laws of
      Canada applicable therein. Microcell and COM Canada hereby unconditionally
      and irrevocably submit to the non-exclusive jurisdiction of the courts of
      the Province of Quebec in respect of all matters arising out of this
      Agreement.

7.5   If any provision of this Agreement is determined to be invalid or
      unenforceable in whole or in part, such invalidity or unenforceability
      shall attach only to such provision or part thereof and the remaining part
      of such provision and all other provisions hereof shall continue in full
      force and effect. The parties hereto agree to negotiate in good faith a
      substitute provision which shall be as close as possible to the intention
      of any invalid or unenforceable provision as may be valid or enforceable.
      The invalidity or unenforceability of any provision in any particular
      jurisdiction shall not affect its validity or enforceability in any other
      jurisdiction where it is valid or enforceable.

7.6   Each party hereto agrees to do all such things and take all such actions
      as may be necessary or desirable to give full force and effect to the
      matters contemplated by this Agreement.

7.7   This Agreement shall enure to the benefit of and be binding upon the
      parties hereto and there respective successors and permitted assigns.

7.8   Failure by any party hereto to insist in any one or more instances upon
      the strict performance of any one of the covenants or rights contained
      herein shall not be construed as a waiver or relinquishment of such
      covenant. No waiver by either party hereto of any such covenant or right
      shall be deemed to have been made unless expressed in writing and signed
      by the waiving party.

7.9   No term or provision hereof may be amended, discharged or terminated
      except by an instrument in writing signed by the party against which the
      enforcement of the amendment, discharge or termination is sought.

7.10  This Agreement may be executed in several counterparts and by facsimile,
      each of which when so executed shall be deemed to be an original and such
      counterparts and facsimiles together shall constitute one and the same
      instrument and notwithstanding their date of execution they shall be
      deemed to be dated as of the date hereof. This Agreement shall be deemed
      to have been entered into and to have become effective at the location at
      which COM Canada shall have signed an original, counterpart or facsimile
      version thereof, without regard to the place at which Microcell shall have
      signed same.

7.11  Time shall be of the essence of this Agreement.

7.12  This Agreement, together with any other agreements and other documents
      referred to herein and delivered in connection herewith, constitutes the
      entire agreement between the parties hereto pertaining to the subject
      matter hereof and supersedes all prior

<PAGE>

                                                                             13.

      agreements, understandings, negotiations and discussions, whether oral or
      written, between the parties with respect to the subject matter hereof.

7.13  The parties hereby confirm their express wish that this document and all
      documents and agreements directly or indirectly related thereto be drawn
      up in English. Les parties aux presentes reconnaissent qu'a leur demande
      le present document ainsi que tous les documents et conventions qui s'y
      rattachent directement ou indirectement sont rediges en langue anglaise.

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<PAGE>

                                                                             14.

IN WITNESS WHEREOF the parties hereto have caused this Agreement to be duly
executed and delivered by their authorized officers as of the date first written
above.

                                       MICROCELL TELECOMMUNICATIONS INC.

                                       By: __________________________________
                                            Name: Jocelyn Cote
                                            Title: Vice-President, Legal Affairs
                                                   and Assistant Secretary

                                       COM CANADA, LLC

                                       By: _____________________________________
                                            Name: Brian Marcinek
                                            Title: Vice-President and  Secretary