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                                                                     EXHIBIT 4.4

      FORM OF PLAN OF ARRANGEMENT INCLUDING EXCHANGEABLE SHARE PROVISIONS

                              PLAN OF ARRANGEMENT
                               UNDER SECTION 192
                    OF THE CANADA BUSINESS CORPORATIONS ACT

                                   ARTICLE 1
                                 INTERPRETATION

1.1 DEFINITIONS

    In this Plan of Arrangement, unless there is something in the subject matter
or context inconsistent therewith, the following terms shall have the respective
meanings set out below and grammatical variations of such terms shall have
corresponding meanings:

    "ADS ELECTED SHARE" means any BioChem Common Share that the holder shall
    have elected, in a duly completed Letter of Transmittal and Election Form
    deposited with the Exchange Agent no later than the Election Deadline, to
    transfer to ExchangeCo under the Arrangement in exchange for a number of
    fully-paid and non-assessable Shire ADSs that is equal to the Exchange Ratio
    divided by three.

    "AFFILIATE" of any Person means any other Person directly or indirectly
    controlling, controlled by, or under common control with, that Person. For
    the purposes of this definition, "CONTROL" (including, with correlative
    meanings, the terms "CONTROLLED BY" and "UNDER COMMON CONTROL WITH"), as
    applied to any Person, means the possession by another Person, directly or
    indirectly, of the power to direct or cause the direction of the management
    and policies of that first mentioned Person, whether through the ownership
    of voting securities, by contract or otherwise.

    "ARRANGEMENT" means the arrangement under Section 192 of the CBCA on the
    terms and subject to the conditions set forth in the Merger Agreement and
    this Plan of Arrangement and subject to any amendments or variations thereto
    made in accordance with Article VIII of the Merger Agreement or Article 6
    hereof or made at the direction of the Court.

    "ARRANGEMENT RESOLUTION" means the special resolution to be passed by the
    BioChem Securityholders at the BioChem Securityholder Meeting, to be
    substantially in the form and content of Exhibit 1.3(b) to the Merger
    Agreement.

    "ARTICLES OF ARRANGEMENT" means the articles of arrangement of BioChem in
    respect of the Arrangement, required by the CBCA to be sent to the Director
    after the Final Order is made.

    "BIOCHEM" means BioChem Pharma Inc., a corporation existing under the laws
    of Canada.

    "BIOCHEM COMMON SHARES" means the common shares in the capital of BioChem
    outstanding from time to time, including all common shares issued on the
    exercise of BioChem Share Options and BioChem Warrants prior to the
    Effective Date.

    "BIOCHEM SECURITYHOLDERS" means, collectively, the holders of BioChem Common
    Shares, the holders of BioChem Share Options and the holders of BioChem
    Warrants, to the extent provided in or required by the Interim Order.

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    "BIOCHEM SECURITYHOLDER MEETING" means the special meeting of the BioChem
    Securityholders (including any adjournment thereof) that is to be convened
    and held as provided by the Interim Order to consider, and if deemed
    advisable to approve, the Arrangement.

    "BIOCHEM SHARE OPTION PLAN" means the share option plan for BioChem's
    directors, officers, employees and consultants.

    "BIOCHEM SHARE OPTIONS" means options to acquire BioChem Common Shares
    granted under the BioChem Share Option Plan.

    "BIOCHEM SHAREHOLDER" means a registered holder of BioChem Common Shares.

    "BIOCHEM WARRANTS" means the right to receive warrants in certain
    circumstances granted in favour of the Government of Canada giving the right
    to acquire BioChem Common Shares at an exercise price equal to the closing
    price on The Toronto Stock Exchange on the day prior to their issuance, the
    whole pursuant to an agreement dated March 31, 2000.

    "BUSINESS DAY" means any day on which banks are not required or authorized
    to close in the City of Montreal, Canada, the City of London, England and
    the City of New York, U.S.A.

    "CALL RIGHT DIVIDEND AMOUNT" has the meaning ascribed to that term in
    Section 5.3(a).

    "CALLCO" means 3829359 Canada Inc., a corporation existing under the laws of
    Canada and being a wholly-owned subsidiary of Shire.

    "CANADIAN RESIDENT" means a Person who is a resident of Canada for the
    purposes of the ITA.

    "CBCA" means the CANADA BUSINESS CORPORATIONS ACT, as now in effect and as
    may be amended from time to time prior to the Effective Date, including the
    regulations made thereunder.

    "CERTIFICATE" means the certificate of arrangement giving effect to the
    Arrangement, issued by the Director pursuant to subsection 192(7) of the
    CBCA after the Articles of Arrangement have been filed.

    "CLOSING DATE" has the meaning ascribed to that term in the Merger
    Agreement.

    "COURT" means the Superior Court of Quebec.

    "CURRENT MARKET PRICE" has the meaning ascribed to that term in the
    Exchangeable Share Provisions.

    "DIRECTOR" means the Director appointed under Section 260 of the CBCA.

    "DISSENT PROCEDURES" has the meaning ascribed to that term in Section 3.1.

    "DISSENTING SHAREHOLDER" means a holder of BioChem Common Shares who
    dissents in respect of the Arrangement in strict compliance with the Dissent
    Procedures.

    "DIVIDEND AMOUNT" has the meaning ascribed to that term in Section 5.1(a).

    "EFFECTIVE DATE" means the date upon which this Plan of Arrangement becomes
    effective as established by the date of issue shown on the Certificate.

    "EFFECTIVE TIME" means 12:01 a.m. (Montreal time) on the Effective Date.

    "ELECTION DEADLINE" means 5:00 p.m. (Montreal time) on the date which is two
    Business Days prior to the date of the BioChem Securityholder Meeting.

    "ENTITY" means any corporation (including any non-profit corporation),
    general partnership, limited partnership, limited liability partnership,
    joint venture, estate, trust, company (including any company limited by
    shares, limited liability company or joint share company), firm, society or
    other enterprise, association, organization or entity.

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    "EXCHANGE AGENT" means General Trust of Canada at its offices at the
    addresses set out in the Letter of Transmittal and Election Form in its
    capacity as an exchange agent for the BioChem Common Shares under the
    Arrangement or such other trust company or other Entity that Shire may, in
    its reasonable discretion, choose as exchange agent.

    "EXCHANGE DATE" has the meaning ascribed to that term in Section 5.3(b).

    "EXCHANGE RATIO" means (i) 2.3517, if the Shire ADS Price is less than or
    equal to US$47.20; (ii) an amount determined by dividing US$37.00 by the
    Shire ADS Price and multiplying by three, if the Shire ADS Price is greater
    than US$47.20 and less than US$70.80; and (iii) 1.5678, if the Shire ADS
    Price is equal to or greater than US$70.80; provided that if, between the
    date of the Merger Agreement and the Effective Time, the outstanding BioChem
    Common Shares or Shire Ordinary Shares are changed into a different number
    or class of shares by reason of any share split, division or subdivision of
    shares, share dividend, reverse share split, consolidation of shares,
    reclassification, recapitalization or other similar transaction, then the
    Exchange Ratio will be adjusted appropriately to provide to the holders of
    BioChem Common Shares the same economic effect as contemplated hereby.

    "EXCHANGEABLE ELECTED SHARE" means any BioChem Common Share that the holder
    shall have elected, in a duly completed Letter of Transmittal and Election
    Form deposited with the Exchange Agent no later than the Election Deadline,
    to transfer to ExchangeCo under the Arrangement in exchange for a number of
    fully paid and non-assessable Exchangeable Shares equal to the Exchange
    Ratio divided by three, or that is deemed to be an Exchangeable Elected
    Share pursuant to Section 2.2(d).

    "EXCHANGEABLE SHARE" means a share in the class of non-voting exchangeable
    shares in the capital of ExchangeCo.

    "EXCHANGEABLE SHARE PROVISIONS" means the rights, privileges, restrictions
    and conditions attaching to the Exchangeable Shares, which rights,
    privileges, restrictions and conditions shall be substantially as set forth
    in Appendix 1 hereto.

    "EXCHANGEABLE SHARE SUPPORT AGREEMENT" means the Exchangeable Share Support
    Agreement among Shire, CallCo and ExchangeCo, to be entered into in
    connection with this Plan of Arrangement.

    "EXCHANGEABLE SHARE VOTING EVENT" has the meaning attributed to that term in
    the Exchangeable Share Provisions.

    "EXCHANGECO" means Shire Acquisition Inc. (formerly 3829341 Canada Inc.), a
    corporation existing under the laws of Canada and being a wholly-owned
    subsidiary of Shire.

    "EXEMPT EXCHANGEABLE SHARE VOTING EVENT" has the meaning attributed to that
    term in the Exchangeable Share Provisions.

    "FINAL ORDER" means the final order of the Court approving the Arrangement,
    following the application therefor contemplated by Section 1.3(e) of the
    Merger Agreement, as such order may be affirmed, amended or modified by the
    Court or by the highest court by which an appeal therefrom is heard at any
    time prior to the Effective Time.

    "GOVERNMENTAL BODY" means any: (a) nation, state, commonwealth, province,
    territory, county, municipality, district or other jurisdiction of any
    nature; (b) federal, state, provincial, local, municipal, foreign or other
    government; or (c) governmental or quasi-governmental authority of any
    nature (including any governmental division, department, agency, commission,
    instrumentality, official, ministry, fund, foundation, center, organization,
    unit, body or Entity and any court or other tribunal).

    "HOLDER" means, when used with reference to any shares, options or warrants,
    the holders of such shares, options or warrants, respectively, shown from
    time to time in the register maintained by or on behalf of the applicable
    corporation in respect thereof.

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    "INTERIM ORDER" means the interim order of the Court made in connection with
    the process for obtaining approval of the Arrangement and related matters
    following the application therefor contemplated by Section 1.3(a) of the
    Merger Agreement, as such order may be affirmed, amended or modified by the
    Court or by the highest court by which an appeal therefrom is heard at any
    time prior to the Effective Time.

    "ITA" means the INCOME TAX ACT (Canada).

    "LETTER OF TRANSMITTAL AND ELECTION FORM" means the Letter of Transmittal
    and Election Form for use by holders of BioChem Common Shares, in the form
    accompanying the Management Information Circular.

    "LIQUIDATION AMOUNT" has the meaning attributed to that term in the
    Exchangeable Share Provisions.

    "LIQUIDATION CALL PURCHASE PRICE" has the meaning ascribed to that term in
    Section 5.1(a).

    "LSE" means the London Stock Exchange plc or its successors.

    "LIQUIDATION CALL RIGHT" has the meaning ascribed to that term in
    Section 5.1(a).

    "LIQUIDATION DATE" has the meaning ascribed to that term in the Exchangeable
    Share Provisions.

    "MANAGEMENT INFORMATION CIRCULAR" means the notice of the BioChem
    Securityholder Meeting and accompanying management information circular of
    BioChem, including all schedules attached thereto, to be sent to BioChem
    Securityholders in connection with the BioChem Securityholder Meeting.

    "MARKET PRICE" has the meaning ascribed to that term in the Merger
    Agreement.

    "MEETING DATE" means the date of the BioChem Securityholder Meeting.

    "MERGER AGREEMENT" means the merger agreement made as of December 10, 2000
    between Shire, ExchangeCo and BioChem, as amended, supplemented and/or
    restated in accordance therewith prior to the Effective Date, providing for,
    among other things, the Arrangement.

    "NASDAQ" means NASDAQ National Market.

    "PERSON" means any individual, Entity or Governmental Body.

    "PLAN OF ARRANGEMENT" means this plan of arrangement proposed under
    Section 192 of the CBCA, as amended, modified or supplemented from time to
    time in accordance with Article 6 hereof or Article VIII of the Merger
    Agreement or any order of the Court, including the appendices hereto and
    including any agreement or instrument supplementary or ancillary hereto.

    "REDEMPTION CALL PURCHASE PRICE" has the meaning ascribed to that term in
    Section 5.2(a).

    "REDEMPTION CALL RIGHT" has the meaning ascribed to that term in
    Section 5.2(a).

    "REDEMPTION DATE" has the meaning ascribed to that term in the Exchangeable
    Share Provisions.

    "REDEMPTION PRICE" has the meaning ascribed to that term in the Exchangeable
    Share Provisions.

    "REPLACEMENT OPTION" has the meaning ascribed to that term in
    Section 2.2(e).

    "REPLACEMENT WARRANT" has the meaning ascribed to that term in
    Section 2.2(f).

    "SHIRE" means Shire Pharmaceuticals Group Plc, a company registered in
    England under registry number 2883758.

    "SHIRE ADS" means an American Depositary Share of Shire, or where
    appropriate, an American Depositary Receipt of Shire, evidencing such share.

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    "SHIRE ADS PRICE" means the Market Price of a Shire ADS (rounded to the
    nearest 1/1000) as of the Closing Date.

    "SHIRE CALL PURCHASE PRICE" has the meaning ascribed to that term in
    Section 5.3(a).

    "SHIRE CALL RIGHT" has the meaning ascribed to that term in Section 5.3(a).

    "SHIRE CONTROL TRANSACTION" has the meaning ascribed to that term in the
    Exchangeable Share Provisions.

    "SHIRE ELECTED SHARE" means any BioChem Common Share that the holder shall
    have elected, in a duly completed Letter of Transmittal and Election Form
    deposited with the Exchange Agent no later than the Election Deadline, to
    transfer to ExchangeCo under the Arrangement in exchange for a number of
    fully-paid and non-assessable Shire Ordinary Shares that is equal to the
    Exchange Ratio, or that is deemed to be a Shire Elected Share pursuant to
    Section 2.2(c) or Section 2.2(d).

    "SHIRE ORDINARY SHARES" means ordinary shares of five pence each in the
    capital of Shire.

    "SPECIAL VOTING SHARES" means the special voting shares of Shire having
    substantially the rights, privileges, restrictions and conditions described
    in the Voting and Exchange Trust Agreement.

    "STAMP TAXES" means all stamp, registration and transfer taxes and duties or
    their equivalents in all jurisdictions where such taxes and duties are
    payable as a result of any of the transactions contemplated by this Plan of
    Arrangement including, without limitation, United Kingdom stamp duty and
    stamp duty reserve tax.

    "TOTAL LIQUIDATION CALL PURCHASE PRICE" means the Liquidation Amount
    multiplied by the relevant number of Exchangeable Shares of a particular
    holder.

    "TOTAL REDEMPTION CALL PURCHASE PRICE" means the Redemption Price multiplied
    by the number of Exchangeable Shares of a particular holder subject to a
    redemption pursuant to Section 7.1.

    "TOTAL SHIRE CALL PURCHASE PRICE" means the Shire Call Purchase Price
    multiplied by the relevant number of Exchangeable Shares subject to the
    Shire Call Right exercised by Shire.

    "TRANSFER AGENT" has the meaning ascribed to that term in Section 5.1(b).

    "TRUSTEE" means General Trust of Canada or such other trust company or other
    Entity that Shire may, in its reasonable discretion, choose to act as
    trustee under the Voting and Exchange Trust Agreement, being a corporation
    organized and existing under the laws of Canada and authorized to carry on
    the business of a trust company in all the provinces of Canada, and any
    successor trustee appointed under the Voting and Exchange Trust Agreement.

    "UKLA" means the United Kingdom Listing Authority.

    "UNITED KINGDOM POUND EQUIVALENT" means, in respect of an amount expressed
    in Canadian dollars at any date, the product obtained by multiplying:
    (a) the number of Canadian dollars, by (b) the exchange rate on such date
    for Canadian dollars expressed in United Kingdom pounds as reported by the
    Bank of Canada or, in the event such spot exchange rate is not available,
    such spot exchange rate on such date for Canadian dollars expressed in
    United Kingdom pounds as may be deemed by the board of directors of BioChem
    and the board of directors of Shire, acting jointly and reasonably, to be
    appropriate for such purpose.

    "VOTING AND EXCHANGE TRUST AGREEMENT" has the meaning ascribed to that term
    in the Exchangeable Share Provisions.

1.2 SECTIONS AND HEADINGS

    The division of this Plan of Arrangement into Articles and sections and the
insertion of headings are for convenience of reference only and shall not affect
the construction or interpretation of this Plan of Arrangement. Unless otherwise
indicated, any reference in this Plan of Arrangement to an article, a section or
an appendix refers to the specified article or section of or appendix to this
Plan of Arrangement.

1.3 NUMBER, GENDER AND PERSONS

    In this Plan of Arrangement, unless the context otherwise requires, words
importing the singular number include the plural and VICE VERSA and words
importing any gender include all genders.

1.4 GOVERNING LAW

    This Plan of Arrangement will be governed by and construed in accordance
with the laws of the Province of Quebec and the laws of Canada applicable
therein.

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                                   ARTICLE 2
                                  ARRANGEMENT

2.1 BINDING EFFECT

    This Plan of Arrangement will become effective at, and be binding at and
after, the Effective Time on (i) BioChem, (ii) Shire, (iii) CallCo,
(iv) ExchangeCo, (v) all holders and all beneficial holders of BioChem Common
Shares, (vi) all holders and all beneficial holders of Exchangeable Shares, and
(vii) all holders and all beneficial holders of BioChem Share Options and
BioChem Warrants.

2.2 ARRANGEMENT

    Commencing at the Effective Time, the following will occur and will be
deemed to occur without any further act or formality:

    (a) each Shire Elected Share will be transferred by the holder thereof,
       without any further act or formality on the part of such holder, to
       ExchangeCo in exchange for that number of fully paid and non-assessable
       Shire Ordinary Shares equal to the Exchange Ratio, and the name of each
       such holder will be removed from the register of holders of BioChem
       Common Shares and added to the register of holders of Shire Ordinary
       Shares, and ExchangeCo will be recorded as the holder of such BioChem
       Common Share so exchanged and will be deemed to be the legal and
       beneficial holder thereof;

    (b) each ADS Elected Share will be transferred by the holder thereof,
       without any further act or formality on the part of such holder, to
       ExchangeCo in exchange for that number of fully paid and non-assessable
       Shire ADSs equal to the Exchange Ratio divided by three, and the name of
       each such holder will be removed from the register of holders of BioChem
       Common Shares and added to the register of holders of Shire ADSs, and
       ExchangeCo will be recorded as the holder of such BioChem Common Share so
       exchanged and will be deemed to be the legal and beneficial holder
       thereof;

    (c) each Exchangeable Elected Share will be transferred by the holder
       thereof, without any act or formality on the part of such holder, to
       ExchangeCo in exchange for (i) that number of fully paid and
       non-assessable Exchangeable Shares equal to the Exchange Ratio divided by
       three together with (ii) the rights and benefits to which such holder
       will be entitled pursuant to or as a result of the Voting and Exchange
       Trust Agreement and the Exchangeable Share Support Agreement, and the
       name of each such holder will be removed from the register of holders of
       BioChem Common Shares and added to the register of holders of
       Exchangeable Shares, and ExchangeCo will be recorded as the holder of
       such BioChem Common Share so exchanged and will be deemed to be the legal
       and beneficial holder thereof; provided that, notwithstanding the
       foregoing, each holder of BioChem Common Shares who is not a Canadian
       Resident will not be entitled to elect to receive Exchangeable Shares,
       and any such election made by any such holder will be deemed to be an
       election to receive Shire Ordinary Shares and each BioChem Common Share
       held by such holder will be deemed to be a Shire Elected Share and will
       be transferred by the holder thereof in accordance with Section 2.2(a);

    (d) each BioChem Common Share in respect of which an election has not been
       made by the holder thereof by the Election Deadline, or in respect of
       which an effective election has not been made, (other than (i) BioChem
       Common Shares held by Dissenting Shareholders who are ultimately entitled
       to be paid the fair value of the BioChem Common Shares held by them and
       (ii) BioChem Common Shares that are held by Shire or any of its
       Affiliates, which shall not be exchanged under this Arrangement and shall
       remain outstanding as BioChem Common Shares) will be deemed to be an
       Exchangeable Elected Share and will be transferred by the holder thereof
       in accordance with Section 2.2(c) without any further act or formality on
       its part; provided that,

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       notwithstanding the foregoing, each BioChem Common Share in respect of
       which an election has not been made or in respect of which an effective
       election has not been made that is held by a holder who is not a Canadian
       Resident (other than (i) BioChem Common Shares held by Dissenting
       Shareholders who are ultimately entitled to be paid the fair value of the
       BioChem Common Shares held by them and (ii) BioChem Common Shares that
       are held by Shire or any of its Affiliates, which shall not be exchanged
       under this Arrangement and shall remain outstanding as BioChem Common
       Shares) will be deemed to be a Shire Elected Share and will be
       transferred by the holder thereof in accordance with Section 2.2(a) and
       any election made by any such holder to receive Exchangeable Shares will
       be deemed to be an election to receive Shire Ordinary Shares;

    (e) subject to applicable securities laws and regulatory requirements, each
       BioChem Share Option which is outstanding and unexercised at or
       immediately prior to the Effective Time will be fully vested in
       accordance with the terms of the BioChem Share Option Plan (whether or
       not otherwise vested) and will be exchanged for an option (a "REPLACEMENT
       OPTION") to purchase a number of Shire Ordinary Shares from Shire equal
       to the product of the Exchange Ratio multiplied by the number of BioChem
       Common Shares subject to such BioChem Share Option immediately prior to
       the Effective Time, rounding down to the nearest whole share. Such
       Replacement Option will be fully vested and will provide for an exercise
       price per Shire Ordinary Share equal to the United Kingdom Pound
       Equivalent (calculated on the Effective Date) of the per share exercise
       price of such BioChem Share Option immediately prior to the Effective
       Time divided by the Exchange Ratio, rounding up to the nearest whole
       penny. The term to expiry, conditions to, restrictions on and manner of
       exercising, and all other terms and provisions of such Replacement Option
       will otherwise be unchanged from those of the BioChem Share Option. Any
       document or agreement previously evidencing a BioChem Share Option will
       thereafter evidence and be deemed to evidence such Replacement Option;
       provided, however, that each Replacement Option issued by Shire in
       accordance with this Section 2.2(e) shall, in accordance with its terms,
       be subject to further adjustment as appropriate to reflect any share
       split, division or subdivision of shares, share dividend, reverse share
       split, consolidation of shares, reclassification, recapitalization or
       other similar transaction subsequent to the Effective Time;

    (f) subject to applicable securities laws and regulatory requirements, each
       BioChem Warrant which is outstanding at or immediately prior to the
       Effective Time, will be exchanged with Shire for a right to receive a
       warrant (a "REPLACEMENT WARRANT") to purchase a number of Shire Ordinary
       Shares calculated pursuant to the valuation formula set out in the
       agreement dated March 31, 2000 between BioChem and the Government of
       Canada. Such Replacement Warrant will provide for an exercise price per
       Shire Ordinary Share equal to the closing price of such shares on the LSE
       on the trading day immediately prior to their issuance. The term to
       expiry, conditions to, restrictions on and manner of exercising, and all
       other terms and provisions of such Replacement Warrant will otherwise
       remain unchanged from those of the BioChem Warrant, and any document or
       agreement previously evidencing a BioChem Warrant will thereafter
       evidence and be deemed to evidence such Replacement Warrant; provided,
       however, that each Replacement Warrant issued by Shire in accordance with
       this Section 2.2(f) shall, in accordance with its terms, be subject to
       further adjustment as appropriate to reflect any share split, division or
       subdivision of shares, share dividend, reverse share split, consolidation
       of shares, reclassification, recapitalization or other similar
       transaction subsequent to the Effective Time; and

    (g) coincident with the transactions set out above in this Section 2.2,
       Shire, ExchangeCo and the Trustee will execute the Voting and Exchange
       Trust Agreement and Shire will issue to and deposit with the Trustee the
       Special Voting Shares, in consideration of the payment to Shire of one
       (1) United Kingdom pound, to be thereafter held of record by the Trustee
       as trustee for and on

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       behalf of, and for the use and benefit of, the holders of the
       Exchangeable Shares in accordance with the Voting and Exchange Trust
       Agreement. All rights of holders of Exchangeable Shares under the Voting
       and Exchange Trust Agreement will be received by them as part of the
       property receivable under Section 2.2(c) or Section 2.2(d) in exchange
       for the BioChem Common Shares.

2.3 ELECTIONS

    (a) Each Canadian Resident who, at or prior to the Election Deadline, is a
       holder of BioChem Common Shares, will be entitled, with respect to all or
       a portion of such shares, to make an election at or prior to the Election
       Deadline to receive Exchangeable Shares, Shire ADSs, Shire Ordinary
       Shares or a combination thereof, in exchange for such holder's BioChem
       Common Shares, on the basis set forth herein and in the Letter of
       Transmittal and Election Form; for greater certainty, a holder of BioChem
       Common Shares who is not a Canadian Resident will not be entitled to
       elect to receive Exchangeable Shares, and any such election otherwise
       made by any such holder shall be and be deemed to be an election to
       receive Shire Ordinary Shares as set forth in Section 2.2(c).

    (b) Holders of BioChem Common Shares who are Canadian Residents, other than
       any such holder who is exempt from tax under the ITA, and who have
       elected to receive consideration that includes Exchangeable Shares in
       exchange for their BioChem Common Shares will be entitled to make an
       income tax election pursuant to subsection 85(1) of the ITA or, if the
       holder is a partnership, subsection 85(2) of the ITA (and in each case,
       if applicable, the analogous provisions of applicable provincial income
       tax legislation) with respect to the transfer of their BioChem Common
       Shares to ExchangeCo by providing three signed copies of the necessary
       election forms to the Exchange Agent within 120 days following the
       Effective Date, duly completed with the details of the number of shares
       transferred and the applicable agreed amounts for the purposes of such
       elections. Thereafter, subject to the election forms being correct and
       complete and complying with the provisions of the ITA (and any applicable
       provincial income tax legislation), the forms will be signed by
       ExchangeCo and two signed copies will be returned to such holders for
       filing with the Canada Customs and Revenue Agency (and the applicable
       provincial tax authority).

    (c) If, between the date of this Plan of Arrangement and the Effective Date,
       the outstanding Shire Ordinary Shares, Shire ADSs or the BioChem Common
       Shares shall have been changed into a different number of shares or
       different class by reason of any reclassification, recapitalization,
       share split, split-up, combination or exchange of shares or any
       extraordinary dividend payable in cash or property or a stock dividend or
       dividend payable in any other securities shall be declared with a record
       date within such period, or any similar event shall have occurred, the
       number of Shire Ordinary Shares, Shire ADSs or Exchangeable Shares to be
       received by the holders of BioChem Common Shares shall be appropriately
       adjusted to provide to the holders of BioChem Common Shares the same
       economic effect as contemplated by this Plan of Arrangement prior to such
       event.

                                   ARTICLE 3
                               RIGHTS OF DISSENT

3.1 RIGHTS OF DISSENT

    Holders of BioChem Common Shares may exercise rights of dissent with respect
to such shares pursuant to and in the manner set forth in Section 190 of the
CBCA and this Section 3.1 (the "DISSENT PROCEDURES") in connection with the
Arrangement; provided that, notwithstanding subsection 190(5) of the CBCA, the
written objection to the Arrangement Resolution referred to in
subsection 190(5) of the CBCA must be received by Shire not later than
5:00 p.m. (Montreal time) on the Business Day preceding the

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BioChem Securityholder Meeting. Holders of BioChem Common Shares who duly
exercise such rights of dissent and who:

    (a) are ultimately entitled to be paid fair value for their BioChem Common
       Shares will be deemed to have transferred such BioChem Common Shares to
       BioChem immediately prior to the Effective Time and such BioChem Common
       Shares will be cancelled as of the Effective Time; or

    (b) are ultimately not entitled, for any reason, to be paid fair value for
       their BioChem Common Shares will be deemed to have participated in the
       Arrangement on the same basis as a non-dissenting and non-electing holder
       of BioChem Common Shares and will receive Exchangeable Shares or Shire
       Ordinary Shares, as the case may be, in accordance with Section 2.2(d),

but in no case will Shire, ExchangeCo, CallCo, the Exchange Agent or any other
Person be required to recognize such holders as holders of BioChem Common Shares
after the Effective Time, and the names of such holders of BioChem Common Shares
will be deleted from the register of holders of BioChem Common Shares at the
Effective Time.

                                   ARTICLE 4
                       CERTIFICATES AND FRACTIONAL SHARES

4.1 EXCHANGE OF CERTIFICATES FOR SHIRE ORDINARY SHARES AND/OR SHIRE ADSS

    At or promptly after the Effective Time, ExchangeCo will deposit, or procure
that there are deposited, with the Exchange Agent, for the benefit of the
holders of BioChem Common Shares who will receive Shire Ordinary Shares and/or
Shire ADSs in connection with the Arrangement, certificates representing
(i) the Shire Ordinary Shares issued pursuant to Section 2.2(a), Section 2.2(c)
or Section 2.2(d) in exchange for Shire Elected Shares and/or (ii) the Shire
ADSs issued pursuant to Section 2.2(b) in exchange for ADS Elected Shares (or
effect the necessary CREST or other electronic transfers). Upon surrender to the
Exchange Agent for cancellation of a certificate which immediately prior to the
Effective Time represented Shire Elected Shares and/or ADS Elected Shares under
the Arrangement, together with such other documents and instruments as would
have been required to effect the transfer of the BioChem Common Shares formerly
represented by such certificate under the CBCA and the by-laws of BioChem and
such additional documents and instruments as the Exchange Agent may reasonably
require, the holder of such surrendered certificate will be entitled to receive
in exchange therefor, and the Exchange Agent shall deliver to such holder, a
certificate or certificates representing that number (rounded down to the
nearest whole number) of Shire Ordinary Shares and/or Shire ADSs which such
holder has the right to receive (or effect the necessary CREST or other
electronic transfers) (together with any dividends or distributions with respect
thereto pursuant to Section 4.3 and any cash in lieu of fractional Shire
Ordinary Shares and/or Shire ADSs pursuant to Section 4.4), and the certificate
so surrendered will forthwith be cancelled. In the event of a transfer of
ownership of BioChem Common Shares which is not registered in the transfer
records of BioChem, a certificate or certificates representing the proper number
of Shire Ordinary Shares and/or Shire ADSs may be issued to the transferee (or
the necessary CREST or other electronic transfer effected) if the certificate
representing such BioChem Common Shares is presented to the Exchange Agent,
accompanied by all documents required to evidence and effect such transfer under
the CBCA and the by-laws of BioChem and such additional documents and
instruments as the Exchange Agent may reasonably require. Until surrendered as
contemplated by this Section 4.1, each certificate which immediately prior to
the Effective Time represented BioChem Common Shares that were exchanged for
Shire Ordinary Shares or Shire ADSs will be deemed at all times after the
Effective Time to represent only the right to receive upon such surrender
(i) the certificate or certificates representing Shire Ordinary Shares and/or
Shire ADSs as contemplated by this Section 4.1 (or have the necessary CREST or
other electronic transfer effected), (ii) a cash payment in lieu of any
fractional Shire Ordinary Shares and/or Shire ADSs as contemplated by
Section 4.4, and (iii) any dividends or distributions with a record

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date after the Effective Time theretofore paid or payable with respect to Shire
Ordinary Shares or Shire ADSs as contemplated by Section 4.3.

4.2 ISSUANCE OF CERTIFICATES REPRESENTING EXCHANGEABLE SHARES

    At or promptly after the Effective Time, ExchangeCo will deposit with the
Exchange Agent, for the benefit of the holders of BioChem Common Shares who will
receive Exchangeable Shares in connection with the Arrangement, certificates
representing the Exchangeable Shares issued pursuant to Section 2.2(c) or
Section 2.2(d) in exchange for Exchangeable Elected Shares. Upon surrender to
the Exchange Agent for cancellation of a certificate which immediately prior to
the Effective Time represented one or more Exchangeable Elected Shares under the
Arrangement, together with such other documents and instruments as would have
been required to effect the transfer of the BioChem Common Shares formerly
represented by such certificate under the CBCA and the by-laws of BioChem and
such additional documents and instruments as the Exchange Agent may reasonably
require, the holder of such surrendered certificate will be entitled to receive
in exchange therefor, and the Exchange Agent will deliver to such holder, a
certificate representing that number (rounded down to the nearest whole number)
of Exchangeable Shares which such holder has the right to receive (together with
any dividends or distributions with respect thereto pursuant to Section 4.3 and
any cash in lieu of fractional Exchangeable Shares pursuant to Section 4.4), and
the certificate so surrendered will forthwith be cancelled. In the event of a
transfer of ownership of BioChem Common Shares that is not registered in the
transfer records of BioChem, a certificate representing the proper number of
Exchangeable Shares may be issued to the transferee if the certificate
representing such BioChem Common Shares is presented to the Exchange Agent,
accompanied by all documents required to evidence and effect such transfer under
the CBCA and the by-laws of BioChem and such additional documents and
instruments as the Exchange Agent may reasonably require. Until surrendered as
contemplated by this Section 4.2, each certificate which immediately prior to
the Effective Time represented BioChem Common Shares that were exchanged for
Exchangeable Shares will be deemed at all times after the Effective Time to
represent only the right to receive upon such surrender (i) the certificate
representing Exchangeable Shares as contemplated by this Section 4.2, (ii) a
cash payment in lieu of any fractional Exchangeable Shares as contemplated by
Section 4.4, and (iii) any dividends or distributions with a record date after
the Effective Time theretofore paid or payable with respect to Exchangeable
Shares as contemplated by Section 4.3.

4.3 DISTRIBUTIONS WITH RESPECT TO UNSURRENDERED CERTIFICATES

    No dividends or other distributions declared or made after the Effective
Time with respect to Exchangeable Shares or Shire Ordinary Shares with a record
date after the Effective Time will be paid to the holder of any unsurrendered
certificate which immediately prior to the Effective Time represented
outstanding BioChem Common Shares that were exchanged pursuant to Section 2.2,
and no cash payment in lieu of fractional shares will be paid to any such holder
pursuant to Section 4.4, unless and until the holder of record of such
certificate shall surrender such certificate in accordance with Section 4.1 or
4.2. Subject to applicable law, at the time of such surrender of any such
certificate, there will be paid to the record holder of the certificates
representing whole BioChem Common Shares, without interest, (i) the amount of
any cash payable in lieu of a fractional Exchangeable Share, Shire ADS or Shire
Ordinary Share to which such holder is entitled pursuant to Section 4.4,
(ii) the amount of dividends or other distributions with a record date after the
Effective Time theretofore paid with respect to such whole Exchangeable Share,
Shire ADS or Shire Ordinary Share, as the case may be, that the holder is
entitled to receive and (iii) on the appropriate payment date, the amount of
dividends or other distributions with a record date after the Effective Time but
prior to surrender and a payment date subsequent to surrender payable with
respect to such whole Exchangeable Share, Shire ADS or Shire Ordinary Share, as
the case may be, that the holder is entitled to receive.

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4.4 NO FRACTIONAL SHARES

    No certificates or scrip representing fractional Exchangeable Shares,
fractional Shire ADSs or fractional Shire Ordinary Shares will be issued (or
CREST or other electronic transfer effected in respect of any fractional share)
upon the surrender for exchange of certificates pursuant to Section 4.1 or 4.2
and no dividend, share split or other change in the capital structure of
ExchangeCo or Shire, as the case may be, will have any effect on any such
fractional share and such fractional interests will not entitle the holder
thereof to exercise any rights as a security holder of ExchangeCo or Shire. In
lieu of any such fractional shares:

    (a) each BioChem Shareholder otherwise entitled to a fractional interest in
       an Exchangeable Share after aggregating all such fractional shares will
       receive a cash payment in Canadian dollars equal to such Person's PRO
       RATA portion of the net proceeds after expenses received by the Exchange
       Agent upon the sale of whole shares representing an accumulation of all
       fractional interests in Exchangeable Shares to which all such Persons
       would otherwise be entitled. The Exchange Agent will sell such
       Exchangeable Shares by way of sale through the facilities of any stock
       exchange upon which the Exchangeable Shares are then listed as soon as
       reasonably practicable following the Effective Date. The aggregate net
       proceeds after expenses of such sale will be distributed by the Exchange
       Agent, PRO RATA in relation to the respective fractions, among the
       Persons otherwise entitled to receive fractional interests in
       Exchangeable Shares;

    (b) each BioChem Shareholder otherwise entitled to a fractional interest in
       a Shire Ordinary Share after aggregating all such fractional shares will
       receive a cash payment in United Kingdom pounds equal to such Person's
       PRO RATA portion of the net proceeds after expenses received by the
       Exchange Agent upon the sale of whole shares representing an accumulation
       of all fractional interests in Shire Ordinary Shares to which all such
       Persons would otherwise be entitled. The Exchange Agent will sell such
       Shire Ordinary Shares by way of sale through the facilities of any stock
       exchange upon which the Shire Ordinary Shares are then listed as soon as
       reasonably practicable following the Effective Date. The aggregate net
       proceeds after expenses of such sale will be distributed by the Exchange
       Agent, PRO RATA in relation to the respective fractions, among the
       Persons otherwise entitled to receive fractional interests in Shire
       Ordinary Shares; and

    (c) each BioChem Shareholder otherwise entitled to a fractional interest in
       a Shire ADS after aggregating all such fractional ADSs will receive a
       cash payment in U.S. dollars equal to such Person's PRO RATA portion of
       the net proceeds after expenses received by the Exchange Agent upon the
       sale of whole ADSs representing an accumulation of all fractional
       interests in Shire ADSs to which all such Persons would otherwise be
       entitled. The Exchange Agent will sell such Shire ADSs by way of sale
       through the facilities of any stock exchange upon which the Shire ADSs
       are then listed as soon as reasonably practicable following the Effective
       Date. The aggregate net proceeds after expenses of such sale will be
       distributed by the Exchange Agent, PRO RATA in relation to the respective
       fractions, among the Persons otherwise entitled to receive fractional
       interests in Shire ADSs.

4.5 LOST CERTIFICATES

    In the event any certificate which immediately prior to the Effective Time
represented one or more outstanding BioChem Common Shares that were exchanged
pursuant to Section 2.2 shall have been lost, stolen or destroyed, upon the
making of an affidavit of that fact by the Person claiming such certificate to
be lost, stolen or destroyed, the Exchange Agent will issue in exchange for such
lost, stolen or destroyed certificate, one or more certificates representing one
or more Exchangeable Shares, Shire ADSs or Shire Ordinary Shares (or effect the
necessary CREST or other electronic transfers) (and a cheque for any dividends
or distributions with respect thereto pursuant to Section 4.3 and any cash in
lieu of fractional interests therein pursuant to Section 4.4) deliverable in
accordance with such holder's Letter of Transmittal

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and Election Form. When authorizing such issuance and payment in exchange for
any lost, stolen or destroyed certificate, the Person to whom certificates
representing Exchangeable Shares, Shire ADSs or Shire Ordinary Shares are to be
issued (or the necessary CREST or other electronic transfers effected) shall, as
a condition precedent to the issuance thereof, give a bond satisfactory to
ExchangeCo, Shire and their respective transfer agents (including the Exchange
Agent) in such sum as Shire may direct or, if Shire permits indemnification in
lieu of a bond, otherwise indemnify ExchangeCo, Shire and their respective
transfer agents (including the Exchange Agent) in a manner satisfactory to Shire
against any claim that may be made against ExchangeCo, Shire and their
respective transfer agents (including the Exchange Agent) with respect to the
certificate alleged to have been lost, stolen or destroyed.

4.6 EXTINCTION OF RIGHTS

    Any certificate which immediately prior to the Effective Time represented
outstanding BioChem Common Shares that were exchanged pursuant to Section 2.2
and not deposited with the Exchange Agent in accordance with Sections 4.1 or
4.2, together with all other instruments required by Sections 4.1 or 4.2, on or
prior to the fifth anniversary of the Effective Date shall cease to represent a
claim or interest of any kind or nature as a shareholder of BioChem, Shire or
ExchangeCo. On such date, the Exchangeable Shares, Shire ADSs or Shire Ordinary
Shares (or cash in lieu of fractional interests therein, as provided in
Section 4.4) to which the former registered holder of the certificate referred
to in the preceding sentence was ultimately entitled shall be deemed to have
been surrendered to ExchangeCo, together with all entitlements to dividends,
distributions and interest thereon held for such former registered holder in
accordance with Section 4.3.

4.7 WITHHOLDING RIGHTS

    ExchangeCo, CallCo, Shire and the Exchange Agent will be entitled to deduct
and withhold from any dividend or consideration otherwise payable to any holder
of BioChem Common Shares, Shire Ordinary Shares, Shire ADSs or Exchangeable
Shares, such amounts as ExchangeCo, CallCo, Shire or the Exchange Agent is
required to deduct and withhold with respect to such payment under the ITA, the
United States INTERNAL REVENUE CODE OF 1986, the United Kingdom tax laws or any
provision of provincial, state, local or foreign tax law, in each case, as
amended. To the extent that amounts are so withheld, such withheld amounts will
be treated for all purposes hereof as having been paid to the holder of the
securities in respect of which such deduction and withholding was made, provided
that such withheld amounts are actually remitted to the appropriate tax
authority. To the extent that the amount so required to be deducted or withheld
from any payment to a holder exceeds the cash portion of the consideration
otherwise payable to the holder, ExchangeCo, CallCo, Shire and the Exchange
Agent are hereby authorized to sell or otherwise dispose of such portion of the
consideration as is necessary to provide sufficient funds to ExchangeCo, CallCo,
Shire or the Exchange Agent, as the case may be, to enable it to comply with
such deduction or withholding requirement and ExchangeCo, CallCo, Shire or the
Exchange Agent will notify the holder thereof and remit to the holder any
unapplied balance of the net proceeds of such sale. ExchangeCo shall not be
entitled to withhold amounts on dividends payable to holders of Exchangeable
Shares pursuant to the United States INTERNAL REVENUE CODE OF 1986 unless it has
received an opinion from counsel stating that such withholding is required under
the INTERNAL REVENUE CODE OF 1986.

4.8 STAMP TAX

    (a) Notwithstanding any other provision herein but subject to
       Section 4.8(b) below, holders of Exchangeable Shares or Persons to whom
       Exchangeable Shares are issued or transferred (in each case other than
       Shire, its Affiliates, the Exchange Agent or the Transfer Agent) shall be
       responsible for any and all Stamp Taxes payable in connection with the
       transfer, exchange, redemption or issuance of such shares or their
       exchange for Shire Ordinary Shares or Shire ADSs and, subject to
       Section 4.8(b) below, transferees of Shire Ordinary Shares or Shire ADSs
       or

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       Persons to whom Shire Ordinary Shares or Shire ADSs are issued (in each
       case other than Shire, its Affiliates, the Exchange Agent or the Transfer
       Agent) shall be responsible for any and all Stamp Taxes payable in
       connection with the transfer or issuance of such securities. In no event,
       subject to Section 4.8(b) below, will Shire, its Affiliates, the Exchange
       Agent or the Transfer Agent be responsible for any such Stamp Taxes and
       Shire, its Affiliates, the Exchange Agent and/or the Transfer Agent shall
       make such regulations and arrangements as are necessary to ensure that
       such holders, such transferees and such Persons pay all such applicable
       Stamp Taxes.

    (b) Shire shall be responsible for (i) any United Kingdom stamp duty and
       stamp duty reserve tax payable on the issue or transfer of Shire Ordinary
       Shares to a depository or to a nominee or agent for a depository pursuant
       to this Arrangement, (ii) any United Kingdom stamp duty reserve tax that
       arises in respect of the transfer of Exchangeable Shares in exchange for
       Shire ADSs and/or Shire Ordinary Shares pursuant to this Arrangement (an
       "Exchange"), (iii) any United Kingdom stamp duty reserve tax that Shire
       or any of its Affiliates requires to be paid on an Exchange, and
       (iv) any United Kingdom stamp duty payable on an issue of Exchangeable
       Shares to a holder of BioChem Common Shares pursuant to this Arrangement.

                                   ARTICLE 5
       CERTAIN RIGHTS OF CALLCO AND SHIRE TO ACQUIRE EXCHANGEABLE SHARES

5.1 CALLCO LIQUIDATION CALL RIGHT

    (a) CallCo will have the overriding right (the "LIQUIDATION CALL RIGHT"), in
       the event of and notwithstanding the proposed liquidation, dissolution or
       winding-up of ExchangeCo pursuant to Article 5 of the Exchangeable Share
       Provisions, to purchase from all but not less than all of the holders of
       Exchangeable Shares (other than any holder of Exchangeable Shares which
       is Shire or an Affiliate of Shire) on the Liquidation Date all but not
       less than all of the Exchangeable Shares held by each such holder on
       payment by CallCo of an amount per share (the "LIQUIDATION CALL PURCHASE
       PRICE") equal to the Current Market Price of a Shire Ordinary Share on
       the last Business Day prior to the Liquidation Date multiplied by three,
       which will be satisfied in full by CallCo causing to be delivered to such
       holder three Shire Ordinary Shares admitted to the official list of the
       UKLA and to trading on the LSE or one Shire ADS quoted on NASDAQ (at the
       option of the holder as indicated to the Transfer Agent), plus, to the
       extent not paid by ExchangeCo, an additional amount equivalent to the
       full amount of all declared and unpaid dividends on each such
       Exchangeable Share held by such holder on any dividend record date which
       occurred prior to the date of purchase by CallCo (the "DIVIDEND AMOUNT").
       In the event of the exercise of the Liquidation Call Right by CallCo,
       each holder (other than Shire or Affiliates of Shire) shall be obligated
       to sell all but not less than all of the Exchangeable Shares held by such
       holder to CallCo on the Liquidation Date on payment by CallCo to the
       holder of the Liquidation Call Purchase Price for each such share, and
       ExchangeCo shall have no obligation to pay the Liquidation Amount of such
       shares so purchased by CallCo.

    (b) To exercise the Liquidation Call Right, CallCo must notify ExchangeCo's
       transfer agent (the "TRANSFER AGENT"), as agent for the holders of
       Exchangeable Shares, and ExchangeCo of CallCo's intention to exercise
       such right at least 45 days before the Liquidation Date in the case of a
       voluntary liquidation, dissolution or winding-up of ExchangeCo and at
       least five Business Days before the Liquidation Date in the case of an
       involuntary liquidation, dissolution or winding-up of ExchangeCo. The
       Transfer Agent will notify the holders of Exchangeable Shares as to
       whether or not CallCo has exercised the Liquidation Call Right forthwith
       after the expiry of the period during which the same may be exercised by
       CallCo. If CallCo exercises the Liquidation Call Right, then on the
       Liquidation Date CallCo will purchase and the holders (other than Shire
       or

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       Affiliates of Shire) will sell all but not less than all of the
       Exchangeable Shares held by such holders for a price per share equal to
       the Liquidation Call Purchase Price.

    (c) For the purposes of completing the purchase of the Exchangeable Shares
       pursuant to the Liquidation Call Right, CallCo will deposit or cause to
       be deposited with the Transfer Agent, on or before the Liquidation Date,
       certificates representing the aggregate number of Shire Ordinary Shares
       and/or Shire ADSs deliverable by CallCo (or effect the necessary CREST or
       other electronic transfers) and a cheque or cheques of CallCo payable at
       par at any branch of the bankers of CallCo representing the aggregate
       Dividend Amount in payment of the Total Liquidation Call Purchase Price,
       less any amounts withheld pursuant to Section 4.7 hereof. Provided that
       CallCo has complied with the immediately preceding sentence, on and after
       the Liquidation Date, the rights of each holder of Exchangeable Shares
       will be limited to receiving the Total Liquidation Call Purchase Price
       payable by CallCo upon presentation and surrender by the holder of
       certificates representing the Exchangeable Shares held by such holder and
       the holder will on and after the Liquidation Date be considered and
       deemed for all purposes to be the holder of the Shire Ordinary Shares
       and/or Shire ADSs to which it is entitled, unless payment of the Total
       Liquidation Call Purchase Price for the Exchangeable Shares shall not be
       made upon presentation and surrender of share certificates in accordance
       with the provisions of this Section 5.1(c), in which case the rights of
       the holders shall remain unaffected until the Total Liquidation Call
       Purchase Price has been paid in the manner herein provided. Upon
       surrender to the Transfer Agent of a certificate or certificates
       representing Exchangeable Shares, together with such other documents and
       instruments as may be required to effect a transfer of Exchangeable
       Shares under the CBCA and the by-laws of ExchangeCo and such additional
       documents and instruments as the Transfer Agent may reasonably require,
       the holder of such surrendered certificate or certificates will be
       entitled to receive in exchange therefor, and the Transfer Agent on
       behalf of CallCo will deliver to such holder as soon as reasonably
       practicable, certificates representing the Shire Ordinary Shares and/or
       Shire ADSs to which the holder is entitled (or effect the necessary CREST
       or other electronic transfers) and a cheque or cheques of CallCo payable
       at par at any branch of the bankers of CallCo in payment of the Dividend
       Amount, and when received by the Transfer Agent, all dividends and other
       distributions with respect to such Shire Ordinary Shares and/or Shire
       ADSs with a record date after the Liquidation Date and before the date of
       the transfer of such Shire Ordinary Shares and/or Shire ADSs to such
       holder, less any amounts withheld pursuant to Section 4.7 hereof. If
       CallCo does not exercise the Liquidation Call Right in the manner
       described above on the Liquidation Date, the holders of the Exchangeable
       Shares (other than Shire or Affiliates of Shire) will be entitled to
       receive in exchange therefor the Liquidation Amount of such shares
       pursuant to Article 5 of the Exchangeable Share Provisions.

5.2 CALLCO REDEMPTION CALL RIGHT

    (a) CallCo will have the overriding right (the "REDEMPTION CALL RIGHT"),
       notwithstanding the proposed redemption of the Exchangeable Shares by
       ExchangeCo pursuant to Article 7 of the Exchangeable Share Provisions, to
       purchase from all but not less than all of the holders of Exchangeable
       Shares (other than any holder of Exchangeable Shares which is Shire or an
       Affiliate of Shire) on the Redemption Date all but not less than all of
       the Exchangeable Shares held by each such holder on payment by CallCo to
       each holder of an amount per Exchangeable Share (the "REDEMPTION CALL
       PURCHASE PRICE") equal to the Current Market Price of a Shire Ordinary
       Share on the last Business Day prior to the Redemption Date multiplied by
       three, which will be satisfied in full by CallCo causing to be delivered
       to such holder three Shire Ordinary Shares admitted to the official list
       of the UKLA and to trading on the LSE or one Shire ADS quoted on NASDAQ
       (at the option of the holder as indicated to the Transfer Agent), plus
       the Dividend Amount. In the event of the exercise of the Redemption Call
       Right by CallCo, each

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       holder (other than Shire or Affiliates of Shire) will be obligated to
       sell all but not less than all the Exchangeable Shares held by such
       holder to CallCo on the Redemption Date on payment by CallCo to the
       holder of the Redemption Call Purchase Price for each such share, and
       ExchangeCo will have no obligation to redeem such shares so purchased by
       CallCo.

    (b) To exercise the Redemption Call Right, CallCo must notify the Transfer
       Agent, as agent for the holders of Exchangeable Shares, and ExchangeCo of
       CallCo's intention to exercise such right at least 60 days before the
       Redemption Date, except in the case of a redemption occurring as a result
       of a Shire Control Transaction, an Exchangeable Share Voting Event or an
       Exempt Exchangeable Share Voting Event, in which case CallCo will so
       notify the Transfer Agent and ExchangeCo on or before the Redemption
       Date. The Transfer Agent will notify the holders of the Exchangeable
       Shares as to whether or not CallCo has exercised the Redemption Call
       Right forthwith after the expiry of the period during which the same may
       be exercised by CallCo. If CallCo exercises the Redemption Call Right, on
       the Redemption Date, CallCo will purchase and the holders (other than
       Shire or Affiliates of Shire) will sell all but not less than all of the
       Exchangeable Shares held by such holders for a price per share equal to
       the Redemption Call Purchase Price.

    (c) For the purposes of completing the purchase of the Exchangeable Shares
       pursuant to the Redemption Call Right, CallCo will deposit or cause to be
       deposited with the Transfer Agent, on or before the Redemption Date,
       certificates representing the aggregate number of Shire Ordinary Shares
       and/or Shire ADSs deliverable by CallCo (or effect the necessary CREST or
       other electronic transfers) and a cheque or cheques of CallCo payable at
       par at any branch of the bankers of CallCo representing the aggregate
       Dividend Amount in payment of the total Redemption Call Purchase Price,
       less any amounts withheld pursuant to Section 4.7 hereof. Provided that
       CallCo has complied with the immediately preceding sentence, on and after
       the Redemption Date the rights of each holder of Exchangeable Shares
       (other than Shire or Affiliates of Shire) will be limited to receiving
       the Total Redemption Call Purchase Price payable by CallCo upon
       presentation and surrender by the holder of certificates representing the
       Exchangeable Shares held by such holder and the holder will on and after
       the Redemption Date be considered and deemed for all purposes to be the
       holder of the Shire Ordinary Shares and/or Shire ADSs to which it is
       entitled, unless payment of the Total Redemption Call Purchase Price for
       the Exchangeable Shares shall not be made upon presentation and surrender
       of share certificates in accordance with the provisions of this
       Section 5.2(c), in which case the rights of the holders shall remain
       unaffected until the Total Redemption Call Purchase Price has been paid
       in the manner herein provided. Upon surrender to the Transfer Agent of a
       certificate or certificates representing Exchangeable Shares, together
       with such other documents and instruments as may be required to effect a
       transfer of Exchangeable Shares under the CBCA and the by-laws of
       ExchangeCo and such additional documents and instruments as the Transfer
       Agent may reasonably require, the holder of such surrendered certificate
       or certificates will be entitled to receive in exchange therefor, and the
       Transfer Agent on behalf of CallCo will deliver to such holder as soon as
       practicable, certificates representing the Shire Ordinary Shares and/or
       Shire ADSs to which the holder is entitled (or effect the necessary CREST
       or other electronic transfers) and a cheque or cheques of CallCo payable
       at par at any branch of the bankers of CallCo in payment of the Dividend
       Amount, less any amounts withheld pursuant to Section 4.7 hereof. If
       CallCo does not exercise the Redemption Call Right in the manner
       described above, on the Redemption Date the holders of the Exchangeable
       Shares (other than Shire or Affiliates of Shire) will be entitled to
       receive in exchange therefor the Redemption Price of such Shares pursuant
       to Article 7 of the Exchangeable Share Provisions.

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5.3 SHIRE CALL RIGHT

    (a) Shire will have the right (the "SHIRE CALL RIGHT") to purchase, or to
       cause CallCo to purchase, from all but not less than all of the holders
       of Exchangeable Shares (other than any holder of Exchangeable Shares
       which is Shire or an Affiliate of Shire) on the Exchange Date all but not
       less than all of the Exchangeable Shares held by each such holder on
       payment by Shire or CallCo, as the case may be, of an amount per share
       (the "SHIRE CALL PURCHASE PRICE") equal to the Current Market Price of a
       Shire Ordinary Share on the last Business Day prior to the Exchange Date
       multiplied by three, which will be satisfied in full by Shire delivering
       or causing to be delivered, or CallCo causing to be delivered, to such
       holder three Shire Ordinary Shares admitted to the official list of the
       UKLA and to trading on the LSE or one Shire ADS quoted on NASDAQ (at the
       option of the holder as indicated to the Transfer Agent), plus, to the
       extent not paid by ExchangeCo, an additional amount equivalent to the
       full amount of all declared and unpaid dividends on each such
       Exchangeable Share held by such holder on any dividend record date which
       occurred prior to the date of purchase by Shire or CallCo pursuant to the
       Shire Call Right (the "CALL RIGHT DIVIDEND AMOUNT"). In the event of the
       exercise of the Shire Call Right by Shire, each holder (other than Shire
       or Affiliates of Shire) shall be obligated to sell all but not less than
       all of the Exchangeable Shares held by such holder to Shire or CallCo, as
       the case may be, on the Exchange Date on payment by Shire or CallCo, as
       the case may be, to the holder of the Shire Call Purchase Price for each
       such share.

    (b) To exercise the Shire Call Right, (i) Shire must notify the Transfer
       Agent, as agent for the holders of Exchangeable Shares, and ExchangeCo of
       Shire's intention to exercise such right at least 45 days before the
       Business Day on which the purchase of such Exchangeable Shares shall
       occur (the "EXCHANGE DATE") and such notice shall specify whether Shire
       or CallCo will effect such purchase, and (ii) Shire must deliver to the
       Transfer Agent and to the Trustee an opinion in writing signed by
       Canadian counsel to Shire (which counsel shall be satisfactory to the
       Trustee) stating that since the Effective Date there has been a change
       enacted to the ITA and other applicable provincial income tax legislation
       to the effect that, and based thereon such opinion shall confirm that,
       the sale by Canadian Resident holders of Exchangeable Shares to Shire or
       CallCo, as the case may be, pursuant to the Shire Call Right will qualify
       as a tax deferred transaction for purposes of the ITA and other
       applicable provincial income tax legislation for holders of Exchangeable
       Shares. The Transfer Agent will notify the holders of Exchangeable Shares
       that the Shire Call Right has been exercised by Shire. If Shire exercises
       the Shire Call Right, then on the Exchange Date Shire or CallCo, as the
       case may be, will purchase and the holders (other than Shire or
       Affiliates of Shire) will sell all but not less than all of the
       Exchangeable Shares held by such holders for a price per share equal to
       the Shire Call Purchase Price.

    (c) For the purposes of completing the purchase of the Exchangeable Shares
       pursuant to the Shire Call Right, Shire will deposit with the Transfer
       Agent, on or before the Exchange Date, certificates representing the
       aggregate number of Shire Ordinary Shares and/or Shire ADSs deliverable
       by Shire or CallCo, as the case may be, (or effect the necessary CREST or
       other electronic transfers) and a cheque or cheques of Shire or CallCo,
       as the case may be, payable at par at any branch of the bankers of Shire
       or CallCo, as the case may be, representing the aggregate Call Right
       Dividend Amount in payment of the Total Shire Call Purchase Price, less
       any amounts withheld pursuant to Section 4.7 hereof. Provided that Shire
       or CallCo, as the case may be, has complied with the immediately
       preceding sentence, on and after the Exchange Date, the rights of each
       holder of Exchangeable Shares will be limited to receiving the Total
       Shire Call Purchase Price upon presentation and surrender by the holder
       of certificates representing the Exchangeable Shares held by such holder
       and the holder will on and after the Exchange Date be considered and
       deemed for all purposes to be the holder of the Shire Ordinary Shares
       and/or

                                       16
<PAGE>
       Shire ADSs to which it is entitled, unless payment of the Total Shire
       Call Purchase Price for the Exchangeable Shares shall not be made upon
       presentation and surrender of share certificates in accordance with the
       provisions of this Section 5.3(c), in which case the rights of the
       holders shall remain unaffected until the Total Shire Call Purchase Price
       has been paid in the manner herein provided. Upon surrender to the
       Transfer Agent of a certificate or certificates representing Exchangeable
       Shares, together with such other documents and instruments as may be
       required to effect a transfer of Exchangeable Shares under the CBCA and
       the by-laws of ExchangeCo and such additional documents and instruments
       as the Transfer Agent may reasonably require, the holder of such
       surrendered certificate or certificates will be entitled to receive in
       exchange therefor, and the Transfer Agent on behalf of Shire or CallCo,
       as the case may be, will deliver to such holder, certificates
       representing the Shire Ordinary Shares and/or Shire ADSs to which the
       holder is entitled (or effect the necessary CREST or other electronic
       transfers) and a cheque or cheques of Shire or CallCo, as the case may
       be, payable at par at any branch of the bankers of Shire or CallCo, as
       the case may be, in payment of the Call Right Dividend Amount and when
       received by the Transfer Agent, all dividends and other distributions
       with respect to such Shire Ordinary Shares and/or Shire ADSs with a
       record date after the Exchange Date and before the date of the transfer
       of such Shire Ordinary Shares and/or Shire ADSs to such holder, less any
       amounts withheld pursuant to Section 4.7 hereof.

                                   ARTICLE 6
                                   AMENDMENTS

6.1 AMENDMENTS TO PLAN OF ARRANGEMENT

    BioChem reserves the right to amend, modify and/or supplement this Plan of
Arrangement prior to the Effective Date provided that each such amendment,
modification and/or supplement is (i) set out in writing, (ii) approved by
Shire, (iii) filed with the Court and, if made following the BioChem
Securityholder Meeting, approved by the Court, and (iv) communicated to holders
of BioChem Common Shares if and as required by the Court.

    Any amendment, modification or supplement to this Plan of Arrangement may be
proposed by BioChem at any time prior to the BioChem Securityholder Meeting
(provided that Shire shall have consented thereto) with or without any other
prior notice or communication, and if so proposed and accepted by the Persons
voting at the BioChem Securityholder Meeting (subject to the requirements set
forth in the Interim Order), will become part of this Plan of Arrangement for
all purposes.

    Any amendment, modification or supplement to this Plan of Arrangement that
is approved or directed by the Court following the BioChem Securityholder
Meeting will be effective only if (i) it is consented to by each of BioChem and
Shire, and (ii) if required by the Court, it is consented to by BioChem
Securityholders voting in the manner directed by the Court.

6.2 FURTHER ASSURANCES

    Each party hereto shall, from time to time, and at all times hereafter, at
the request of the other parties hereto, but without further consideration, do
all such further acts and execute and deliver all such further documents and
instruments as shall be reasonably required in order to fully perform and carry
out the terms and intent hereof.

                                       17
<PAGE>
                     APPENDIX 1 TO THE PLAN OF ARRANGEMENT

   PROVISIONS ATTACHING TO THE EXCHANGEABLE SHARES OF SHIRE ACQUISITION INC.

    The Exchangeable Shares of Shire Acquisition Inc. shall have the following
rights, privileges, restrictions and conditions:

                                   ARTICLE 1
                                 INTERPRETATION

1.1 FOR THE PURPOSES OF THESE SHARE PROVISIONS:

    "AFFILIATE" of any Person means any other Person directly or indirectly
    controlling, controlled by, or under common control with, that Person. For
    the purposes of this definition, "control" (including, with correlative
    meanings, the terms "controlled by" and "under common control with"), as
    applied to any Person, means the possession by another Person, directly or
    indirectly, of the power to direct or cause the direction of the management
    and policies of that first mentioned Person, whether through the ownership
    of voting securities, by contract or otherwise.

    "BIOCHEM" means BioChem Pharma Inc., a corporation existing under the laws
    of Canada.

    "BOARD OF DIRECTORS" means the board of directors of the Corporation.

    "BUSINESS DAY" means any day on which banks are not required or authorized
    to close in the City of Montreal, Canada, the City of London, England and
    the City of New York, U.S.A.

    "CALLCO" means 3829359 Canada Inc., a corporation existing under the laws of
    Canada and being a wholly-owned subsidiary of Shire.

    "CALLCO CALL NOTICE" has the meaning ascribed to that term in Section 6.3 of
    these share provisions.

    "CANADIAN DOLLAR EQUIVALENT" means, in respect of an amount expressed in a
    currency other than Canadian dollars (the "Foreign Currency Amount") at any
    date, the product obtained by multiplying: (a) the Foreign Currency Amount,
    by (b) the noon spot exchange rate on such date for such foreign currency
    expressed in Canadian dollars as reported by the Bank of Canada or, in the
    event such spot exchange rate is not available, such spot exchange rate on
    such date for such foreign currency expressed in Canadian dollars as may be
    deemed by the Board of Directors to be appropriate for such purpose.

    "CBCA" means the CANADA BUSINESS CORPORATIONS ACT.

    "COMMON SHARE" means a share in the class of common shares in the capital of
    the Corporation.

    "CORPORATION" means Shire Acquisition Inc. (formerly 3829341 Canada Inc.), a
    corporation existing under the laws of Canada and being a wholly-owned
    subsidiary of Shire.

    "CURRENT MARKET PRICE" means, in respect of a Shire Ordinary Share on any
    date, the Canadian Dollar Equivalent of the average of the closing prices of
    Shire Ordinary Shares during a period of 20 consecutive trading days ending
    not more than three trading days before such date on the LSE, or, if the
    Shire Ordinary Shares are not then admitted to the official list of the UKLA
    and to trading on the LSE, on such other stock exchange or automated
    quotation system on which the Shire Ordinary Shares are listed or quoted, as
    the case may be, as may be selected by the Board of Directors for such
    purpose; provided, however, that if in the opinion of the Board of Directors
    the public distribution or trading activity of Shire Ordinary Shares during
    such period does not create a market which reflects the fair market value of
    a Shire Ordinary Share, then the Current Market Price of a Shire Ordinary
    Share shall be determined by the Board of Directors, in good faith and in
    its sole discretion, and

                                       18
<PAGE>
    provided further that any such selection, opinion or determination by the
    Board of Directors shall be conclusive and binding.

    "DIVIDEND AMOUNT" has the meaning ascribed to that term in Section 6.3 of
    these share provisions.

    "EFFECTIVE DATE" has the meaning ascribed to that term in the Plan of
    Arrangement.

    "ENTITY" means any corporation (including any non-profit corporation),
    general partnership, limited partnership, limited liability partnership,
    joint venture, estate, trust, company (including any company limited by
    shares, limited liability company or joint stock company), firm, society or
    other enterprise, association, organization or entity.

    "EXCHANGE AGENT" means General Trust of Canada at its offices at the
    addresses set out in the Letter of Transmittal and Election Form in its
    capacity as an exchange agent for the common shares of the share capital of
    BioChem under the Plan of Arrangement or such other trust company or other
    Entity that Shire may, in its reasonable discretion, choose as exchange
    agent.

    "EXCHANGEABLE SHARE" means a share in the class of non-voting exchangeable
    shares in the capital of the Corporation having the rights, privileges,
    restrictions and conditions set forth herein.

    "EXCHANGEABLE SHARE SUPPORT AGREEMENT" means the Exchangeable Share Support
    Agreement among Shire, CallCo and the Corporation, to be entered into in
    connection with the Plan of Arrangement.

    "EXCHANGEABLE SHARE VOTING EVENT" means any matter in respect of which
    holders of Exchangeable Shares are entitled to vote as shareholders of the
    Corporation, other than an Exempt Exchangeable Share Voting Event, and, for
    greater certainty, excluding any matter in respect of which holders of
    Exchangeable Shares are entitled to vote (or instruct the Trustee to vote)
    in their capacity as Beneficiaries under (and as that term is defined in)
    the Voting and Exchange Trust Agreement.

    "EXEMPT EXCHANGEABLE SHARE VOTING EVENT" means any matter in respect of
    which holders of Exchangeable Shares are entitled to vote as shareholders of
    the Corporation in order to approve or disapprove, as applicable, any change
    to, or in the rights of the holders of, the Exchangeable Shares, where the
    approval or disapproval, as applicable, of such change would be required to
    maintain the equivalence of the Exchangeable Shares and the Shire Ordinary
    Shares.

    "GOVERNMENTAL BODY" means any: (a) nation, state, commonwealth, province,
    territory, county, municipality, district or other jurisdiction of any
    nature; (b) federal, state, provincial, local, municipal, foreign or other
    government; or (c) governmental or quasi-governmental authority of any
    nature (including any governmental division, department, agency, commission,
    instrumentality, official, ministry, fund, foundation, centre, organization,
    unit, body or Entity and any court or other tribunal).

    "HOLDER" means, when used with reference to any shares, options or warrants,
    the holders of such shares, options or warrants, respectively, shown from
    time to time in the register maintained by or on behalf of the applicable
    corporation in respect thereof.

    "LETTER OF TRANSMITTAL AND ELECTION FORM" has the meaning ascribed to that
    term in the Plan of Arrangement.

    "LIQUIDATION AMOUNT" has the meaning ascribed to that term in Section 5.1 of
    these share provisions.

    "LIQUIDATION CALL RIGHT" has the meaning ascribed to that term in the Plan
    of Arrangement.

    "LIQUIDATION DATE" has the meaning ascribed to that term in Section 5.1 of
    these share provisions.

    "LSE" means the London Stock Exchange Plc or its successors.

    "NASDAQ" means NASDAQ National Market.

    "PERSON" means any individual, Entity or Governmental Body.

                                       19
<PAGE>
    "PLAN OF ARRANGEMENT" means the plan of arrangement relating to the
    arrangement of BioChem under Section 192 of the CBCA, as amended, modified
    or supplemented from time to time in accordance with the plan and any order
    of the Superior Court of Quebec, to which plan these share provisions are
    attached as Appendix 1.

    "PURCHASE PRICE" has the meaning ascribed to that term in Section 6.3 of
    these share provisions.

    "REDEMPTION CALL PURCHASE PRICE" has the meaning ascribed to that term in
    the Plan of Arrangement.

    "REDEMPTION CALL RIGHT" has the meaning ascribed to that term in the Plan of
    Arrangement.

    "REDEMPTION DATE" means the date, if any, established by the Board of
    Directors for the redemption by the Corporation of all but not less than all
    of the outstanding Exchangeable Shares pursuant to Article 7 of these share
    provisions, which date shall be no earlier than the tenth anniversary of the
    Effective Date unless:

    (a) there are fewer than 1,000,000 Exchangeable Shares outstanding (other
       than Exchangeable Shares held by Shire and its Affiliates, and as such
       number of shares may be adjusted as deemed appropriate by the Board of
       Directors to give effect to any subdivision or consolidation of or share
       dividend on the Exchangeable Shares, any issue or distribution of rights
       to acquire Exchangeable Shares or securities exercisable or exchangeable
       for or convertible into Exchangeable Shares, any issue or distribution of
       other securities or rights or evidences of indebtedness or assets, or any
       other capital reorganization or other transaction affecting the
       Exchangeable Shares), in which case the Board of Directors may accelerate
       such redemption date to such date prior to the tenth anniversary of the
       Effective Date as they may determine, upon at least 60 days' prior
       written notice to the registered holders of the Exchangeable Shares and
       the Trustee;

    (b) a Shire Control Transaction occurs, in which case, provided that the
       Board of Directors determines, in good faith and in its sole discretion,
       that it is not reasonably practicable to substantially replicate or
       modify the terms and conditions of the Exchangeable Shares in connection
       with such Shire Control Transaction or that the redemption of all but not
       less than all of the outstanding Exchangeable Shares is necessary to
       enable the completion of such Shire Control Transaction in accordance
       with its terms, the Board of Directors may accelerate such redemption
       date to such date prior to the tenth anniversary of the Effective Date as
       it may determine, upon such number of days' prior written notice to the
       registered holders of the Exchangeable Shares and to Shire and CallCo and
       the Trustee as the Board of Directors may determine to be reasonably
       practicable in such circumstances;

    (c) an Exchangeable Share Voting Event is proposed and (i) the Board of
       Directors has determined, in good faith and in its sole discretion, that
       it is not reasonably practicable to accomplish the business purpose
       intended by the Exchangeable Share Voting Event, which business purpose
       must be bona fide and not for the primary purpose of causing the
       occurrence of a Redemption Date, in any other commercially reasonable
       manner that does not result in an Exchangeable Share Voting Event, and
       (ii) the holders of the Exchangeable Shares fail to take the necessary
       action at a meeting or other vote of holders of Exchangeable Shares to
       approve or disapprove, as applicable, the Exchangeable Share Voting
       Event, in which case the redemption date shall be the Business Day
       following the day on which the holders of the Exchangeable Shares failed
       to take such action; or

    (d) an Exempt Exchangeable Share Voting Event is proposed and the holders of
       the Exchangeable Shares fail to take the necessary action at a meeting or
       other vote of holders of Exchangeable Shares, to approve or disapprove,
       as applicable, the Exempt Exchangeable Share Voting Event, in which case
       the Redemption Date shall be the Business Day following the day on which
       the holders of the Exchangeable Shares failed to take such action and the
       Board of Directors shall

                                       20
<PAGE>
       give such number of days' prior written notice of such redemption to the
       registered holders of the Exchangeable Shares as the Board of Directors
       may determine to be reasonably practicable in such circumstances,

    provided, however, that the accidental failure or omission to give any
    notice of redemption under clause (a), (b), (c) or (d) above to less than
    10% of such holders of Exchangeable Shares shall not affect the validity of
    any such redemption.

    "REDEMPTION PRICE" has the meaning ascribed to that term in Section 7.1 of
    these share provisions.

    "RETRACTED SHARES" has the meaning ascribed to that term in Section 6.1(a)
    of these share provisions.

    "RETRACTION CALL RIGHT" has the meaning ascribed to that term in
    Section 6.1(c) of these share provisions.

    "RETRACTION DATE" has the meaning ascribed to that term in Section 6.1(b) of
    these share provisions.

    "RETRACTION PRICE" has the meaning ascribed to that term in Section 6.1 of
    these share provisions.

    "RETRACTION REQUEST" has the meaning ascribed to that term in Section 6.1 of
    these share provisions.

    "SHIRE" means Shire Pharmaceuticals Group Plc, a company registered in
    England under registry number 2883758.

    "SHIRE ADS" means an American Depositary Shares of Shire, or where
    appropriate, an American Depositary Receipt of Shire, evidencing such share.

    "SHIRE CALL RIGHT" has the meaning ascribed to that term in the Plan of
    Arrangement.

    "SHIRE CONTROL TRANSACTION" shall be deemed to have occurred if:

    (a) any person, firm or corporation acquires directly or indirectly any
       voting security of Shire and immediately after such acquisition, the
       acquirer has voting securities representing more than 50% of the total
       voting power of all the then outstanding voting securities of Shire on a
       fully-diluted basis;

    (b) the shareholders of Shire shall approve a merger, consolidation,
       recapitalization or reorganization of Shire, other than any such
       transaction which would result in the holders of outstanding voting
       securities of Shire immediately prior to such transaction having at least
       75% of the total voting power represented by the voting securities of the
       surviving entity outstanding immediately after such transaction, with the
       voting power of each such continuing holder relative to such other
       continuing holders being not altered substantially in the transaction; or

    (c) the shareholders of Shire shall approve a plan of complete liquidation
       of Shire or an agreement for the sale or disposition by Shire of all or a
       substantial portion of Shire's assets (i.e., 66 2/3% or more in fair
       market value of the total assets of Shire).

    "SHIRE DIVIDEND DECLARATION DATE" means the date on which the board of
    directors of Shire declares any dividend on the Shire Ordinary Shares.

    "SHIRE ORDINARY SHARES" means ordinary shares of five pence each in the
    capital of Shire.

    "STAMP TAXES" means all stamp, registration and transfer taxes and duties or
    their equivalents in all jurisdictions where such taxes and duties are
    payable as a result of any of the transactions contemplated by the Plan of
    Arrangement including, without limitation, United Kingdom stamp duty and
    stamp duty reserve tax.

    "TOTAL LIQUIDATION AMOUNT" means the Liquidation Amount multiplied by the
    relevant number of Exchangeable Shares of a particular holder.

                                       21
<PAGE>
    "TOTAL PURCHASE PRICE" means the Purchase Price multiplied by the relevant
    number of Retracted Shares subject to the Retraction Call Right exercised by
    Callco.

    "TOTAL REDEMPTION PRICE" means the Redemption Price multiplied by the number
    of Exchangeable Shares of a particular holder subject to a redemption
    pursuant to Section 7.1.

    "TOTAL RETRACTION PRICE" means the Retraction Price multiplied by the
    relevant number of Retracted Share of a particular holder.

    "TRANSFER AGENT" means General Trust of Canada or such other Person as may
    from time to time be appointed by the Corporation as the registrar and
    transfer agent for the Exchangeable Shares.

    "TRUSTEE" means General Trust of Canada or such other trust company or other
    Entity that Shire may, in its reasonable discretion, choose to act as
    trustee under the Voting and Exchange Trust Agreement, being a corporation
    organized and existing under the laws of Canada and authorized to carry on
    the business of a trust company in all the provinces of Canada, and any
    successor trustee appointed under the Voting and Exchange Trust Agreement.

    "UKLA" means the United Kingdom Listing Authority.

    "VOTING AND EXCHANGE TRUST AGREEMENT" means the Voting and Exchange Trust
    Agreement among Shire, the Corporation and the Trustee, to be entered into
    in connection with the Plan of Arrangement.

                                   ARTICLE 2
                         RANKING OF EXCHANGEABLE SHARES

2.1   The Exchangeable Shares shall be entitled to a preference over the Common
Shares and any other shares ranking junior to the Exchangeable Shares with
respect to the payment of dividends and the distribution of assets in the event
of the liquidation, dissolution or winding-up of the Corporation, whether
voluntary or involuntary, or any other distribution of the assets of the
Corporation, among its shareholders for the purpose of winding up its affairs.

                                   ARTICLE 3
                                   DIVIDENDS

3.1   A holder of an Exchangeable Share shall be entitled to receive and the
Board of Directors shall, subject to applicable law, on each Shire Dividend
Declaration Date, declare a dividend on each Exchangeable Share:

    (a) in the case of a cash dividend declared on the Shire Ordinary Shares, in
       an amount in cash for each Exchangeable Share in United Kingdom pounds,
       or the Canadian Dollar Equivalent thereof on the Shire Dividend
       Declaration Date, in each case, equal to the cash dividend declared on
       each Shire Ordinary Share multiplied by three;

    (b) in the case of a share dividend declared on the Shire Ordinary Shares to
       be paid in Shire Ordinary Shares, in such number of Exchangeable Shares
       (with nominal paid-up capital for purposes of the INCOME TAX ACT
       (Canada)) for each Exchangeable Share as is equal to the number of Shire
       Ordinary Shares divided by three to be paid on each Shire Ordinary Share;
       or

    (c) in the case of a dividend declared on the Shire Ordinary Shares in
       property other than cash or Shire Ordinary Shares, in such type and
       amount of property for each Exchangeable Share as is the same as or
       economically equivalent to (to be determined by the Board of Directors as
       contemplated by Section 3.6 hereof) the type and amount of property
       declared as a dividend on each Shire Ordinary Share multiplied by three.

Such dividends shall be paid out of money, assets or property of the Corporation
properly applicable to the payment of dividends, or out of authorized but
unissued shares of the Corporation, as applicable.

                                       22
<PAGE>
3.2   In the case of a share dividend declared on the Shire Ordinary Shares to
be paid in Shire Ordinary Shares, in lieu of declaring the share dividend
contemplated by Section 3.1(b) on the Exchangeable Shares, the Board of
Directors may, in good faith and in its discretion and subject to applicable
law, subdivide, redivide or change (the "Subdivision") each issued and unissued
Exchangeable Share on the basis that each Exchangeable Share before the
subdivision becomes a number of Exchangeable Shares as is equal to the sum of
(i) three Shire Ordinary Shares and (ii) the number of Shire Ordinary Shares to
be paid as a share dividend on each Shire Ordinary Share. In making such
Subdivision, the Board of Directors shall consider the effect thereof upon the
then outstanding Exchangeable Shares and the general taxation consequences of
the Subdivision to the holders of the Exchangeable Shares. In such instance, and
notwithstanding any other provision hereof, such Subdivision shall become
effective on the effective date specified in Section 3.4 hereof without any
further act or formality on the part of the Board of Directors or of the holders
of Exchangeable Shares. For greater certainty, subject to the applicable laws,
no approval of the holders of Exchangeable Shares to an amendment to the
articles of the Corporation shall be required to give effect to such
subdivision.

3.3   Cheques of the Corporation payable at par at any branch of the bankers of
the Corporation shall be issued in respect of any cash dividends contemplated by
Section 3.1(a) hereof and the sending of such a cheque to each holder of an
Exchangeable Share shall satisfy the cash dividend represented thereby unless
the cheque is not paid on presentation. Subject to applicable law, certificates
registered in the name of the registered holder of Exchangeable Shares shall be
issued or transferred in respect of any share dividends contemplated by
Section 3.1(b) hereof or the Subdivision of Exchangeable Shares contemplated by
Section 3.2 hereof and the sending of such a certificate to each holder of an
Exchangeable Share shall satisfy the share dividend represented thereby. Such
other type and amount of property in respect of any dividends contemplated by
Section 3.1(c) hereof shall be issued, distributed or transferred by the
Corporation in such manner as it shall determine and the issuance, distribution
or transfer thereof by the Corporation to each holder of an Exchangeable Share
shall satisfy the dividend represented thereby. No holder of an Exchangeable
Share shall be entitled to recover by action or other legal process against the
Corporation any dividend that is represented by a cheque that has not been duly
presented to the Corporation's bankers for payment or that otherwise remains
unclaimed for a period of six years from the date on which such dividend was
payable.

3.4   The record date for the determination of the holders of Exchangeable
Shares entitled to receive payment of, and the payment date for, any dividend
declared on the Exchangeable Shares under Section 3.1 hereof shall be the same
dates as the record date and payment date, respectively, for the corresponding
dividend declared on the Shire Ordinary Shares. The record date for the
determination of the holder of Exchangeable Shares entitled to receive
Exchangeable Shares in connection with any Subdivision of Exchangeable Shares
under Section 3.2 hereof and the effective date of such Subdivision shall be the
same dates as the record date and payment date, respectively, for the
corresponding share dividend declared on Shire Ordinary Shares.

3.5   If on any payment date for any dividends declared on the Exchangeable
Shares under Section 3.1 hereof the dividends are not paid in full on all of the
Exchangeable Shares then outstanding, any such dividends that remain unpaid
shall be paid on a subsequent date or dates determined by the Board of Directors
on which the Corporation shall have sufficient moneys, assets or property
properly applicable to the payment of such dividends.

3.6   The Board of Directors shall determine, in good faith and in its sole
discretion, economic equivalence for the purposes of Sections 3.1 and 3.2
hereof, and each such determination shall be conclusive and binding on the
Corporation and its shareholders. In making each such determination, the

                                       23
<PAGE>
following factors shall, without excluding other factors determined by the Board
of Directors to be relevant, be considered by the Board of Directors:

    (a) in the case of any share dividend or other distribution payable in Shire
       Ordinary Shares, the number of such shares issued in proportion to the
       number of Shire Ordinary Shares previously outstanding;

    (b) in the case of the issuance or distribution of any rights, options or
       warrants to subscribe for or purchase Shire Ordinary Shares (or
       securities exercisable or exchangeable for or convertible into or
       carrying rights to acquire Shire Ordinary Shares), the relationship
       between the exercise price of each such right, option or warrant and the
       current market value (as determined by the Board of Directors in the
       manner above contemplated) of a Shire Ordinary Share;

    (c) in the case of the issuance or distribution of any other form of
       property (including without limitation any shares or securities of Shire
       of any class other than Shire Ordinary Shares, any rights, options or
       warrants other than those referred to in Section 3.6(b) above, any
       evidences of indebtedness of Shire or any assets of Shire), the
       relationship between the fair market value (as determined by the Board of
       Directors in the manner above contemplated) of such property to be issued
       or distributed with respect to each outstanding Shire Ordinary Share and
       the current market value (as determined by the Board of Directors in the
       manner above contemplated) of a Shire Ordinary Share; and

    (d) in all such cases, the general taxation consequences of the relevant
       event to holders of Exchangeable Shares to the extent that such
       consequences may differ from the taxation consequences to holders of
       Shire Ordinary Shares as a result of differences between taxation laws of
       Canada and the United Kingdom (except for any differing consequences
       arising as a result of differing marginal taxation rates and without
       regard to the individual circumstances of holders of Exchangeable
       Shares).

    For purposes of the foregoing determinations, the current market value of
any security listed and traded or quoted on a securities exchange shall be the
weighted average of the daily trading prices of such security during a period of
not less than 20 consecutive trading days ending not more than three trading
days before the date of determination on the principal securities exchange on
which such securities are listed and traded or quoted; provided, however, that
if in the opinion of the Board of Directors the public distribution or trading
activity of such securities during such period does not create a market which
reflects the fair market value of such securities, then the current market value
thereof shall be determined by the Board of Directors, in good faith and in its
sole discretion, and provided further that any such determination by the Board
of Directors shall be conclusive and binding on the Corporation and its
shareholders.

                                   ARTICLE 4
                              CERTAIN RESTRICTIONS

4.1   So long as any of the Exchangeable Shares are outstanding, the Corporation
shall not at any time without, but may at any time with, the approval of the
holders of the Exchangeable Shares given as specified in Section 9.2 of these
share provisions:

    (a) pay any dividends on the Common Shares or any other shares ranking
       junior to the Exchangeable Shares, other than share dividends payable in
       Common Shares or any such other shares ranking junior to the Exchangeable
       Shares, as the case may be;

    (b) redeem or purchase or make any capital distribution in respect of Common
       Shares or any other shares ranking junior to the Exchangeable Shares;

                                       24
<PAGE>
    (c) redeem or purchase any other shares of the Corporation ranking equally
       with or junior to the Exchangeable Shares with respect to the payment of
       dividends or on any distribution on liquidation; or

    (d) issue any Exchangeable Shares or any other shares of the Corporation
       ranking equally with, or superior to, the Exchangeable Shares other than
       by way of share dividends to the holders of such Exchangeable Shares.

    The restrictions in Sections 4.1(a), 4.1(b), 4.1(c) and 4.1(d) above shall
not apply if all dividends on the outstanding Exchangeable Shares corresponding
to dividends declared and paid to date on the Shire Ordinary Shares shall have
been declared and paid on the Exchangeable Shares.

                                   ARTICLE 5
                          DISTRIBUTION ON LIQUIDATION

5.1   In the event of the liquidation, dissolution or winding-up of the
Corporation or any other distribution of the assets of the Corporation among its
shareholders for the purpose of winding up its affairs, subject to the exercise
by CallCo of the Liquidation Call Right, a holder of Exchangeable Shares shall
be entitled, subject to applicable law, to receive from the assets of the
Corporation in respect of each Exchangeable Share held by such holder on the
effective date (the "Liquidation Date") of such liquidation, dissolution or
winding-up, before any distribution of any part of the assets of the Corporation
among the holders of the Common Shares or any other shares ranking junior to the
Exchangeable Shares, an amount per share equal to the Current Market Price of a
Shire Ordinary Share on the last Business Day prior to the Liquidation Date
multiplied by three, which shall be satisfied in full by the Corporation causing
to be delivered to such holder three Shire Ordinary Shares admitted to the
official list of the UKLA and to trading on the LSE or one Shire ADS quoted on
NASDAQ (at the option of the holder as indicated to the Transfer Agent),
together with all declared and unpaid dividends on each such Exchangeable Share
held by such holder on any dividend record date which occurred prior to the
Liquidation Date (the "Liquidation Amount").

5.2   On or promptly after the Liquidation Date, and subject to the exercise by
CallCo of the Liquidation Call Right, the Corporation shall pay or cause to be
paid to the holders of the Exchangeable Shares the Liquidation Amount for each
such Exchangeable Share upon presentation and surrender of the certificates
representing such Exchangeable Shares, together with such other documents and
instruments as are required to effect a transfer of Exchangeable Shares under
the CBCA and the by-laws of the Corporation and such additional documents and
instruments as the Transfer Agent or the Corporation may reasonably require, at
the registered office of the Corporation or at any office of the Transfer Agent
as may be specified by the Corporation by notice to the holders of the
Exchangeable Shares. Payment of the Total Liquidation Amount for such
Exchangeable Shares shall be made by delivery to each holder, at the address of
the holder recorded in the securities register of the Corporation for the
Exchangeable Shares or by holding for pick-up by the holder at the registered
office of the Corporation or at any office of the Transfer Agent as may be
specified by the Corporation by notice to the holders of Exchangeable Shares, on
behalf of the Corporation of certificates representing Shire Ordinary Shares
and/or Shire ADSs (or by effecting the necessary CREST or other electronic
transfers) (which shares shall be duly issued as fully paid and non-assessable
and shall be free and clear of any lien, claim or encumbrance) and a cheque of
the Corporation payable at par at any branch of the bankers of the Corporation
in respect of the remaining portion, if any, of the Total Liquidation Amount (in
each case less any amounts withheld on account of tax required to be deducted
and withheld therefrom). On and after the Liquidation Date, the holders of the
Exchangeable Shares shall cease to be holders of such Exchangeable Shares and
shall not be entitled to exercise any of the rights of holders in respect
thereof, other than the right to receive the Total Liquidation Amount, unless
payment of the Total Liquidation Amount for such Exchangeable Shares shall not
be made upon presentation and surrender of share certificates in accordance with
the foregoing provisions, in which

                                       25
<PAGE>
case the rights of the holders shall remain unaffected until the Total
Liquidation Amount has been paid in the manner hereinbefore provided. The
Corporation shall have the right at any time after the Liquidation Date to
deposit or cause to be deposited the Total Liquidation Amount in respect of the
Exchangeable Shares represented by certificates that have not at the Liquidation
Date been surrendered by the holders thereof in a custodial account with any
chartered bank or trust company in Canada. Upon such deposit being made, the
rights of the holders of Exchangeable Shares after such deposit shall be limited
to receiving the Total Liquidation Amount (in each case less any amounts
withheld on account of tax required to be deducted and withheld therefrom) for
such Exchangeable Shares so deposited, against presentation and surrender of the
said certificates held by them, respectively, in accordance with the foregoing
provisions. Upon such payment or deposit of the Total Liquidation Amount, the
holders of the Exchangeable Shares shall thereafter be considered and deemed for
all purposes to be holders of the Shire Ordinary Shares and/or Shire ADSs
delivered to them or the custodian on their behalf.

5.3   After the Corporation has satisfied its obligations to pay the holders of
the Exchangeable Shares the Liquidation Amount per Exchangeable Share pursuant
to Section 5.1 of these share provisions, such holders shall not be entitled to
share in any further distribution of the assets of the Corporation.

                                   ARTICLE 6
                  RETRACTION OF EXCHANGEABLE SHARES BY HOLDER

6.1   A holder of Exchangeable Shares shall be entitled at any time, subject to
the exercise by CallCo of the Retraction Call Right and otherwise upon
compliance with the provisions of this Article 6, to require the Corporation to
redeem any or all of the Exchangeable Shares registered in the name of such
holder for an amount per share equal to the Current Market Price of a Shire
Ordinary Share on the last Business Day prior to the Retraction Date multiplied
by three, which shall be satisfied in full by the Corporation causing to be
delivered to such holder three Shire Ordinary Shares admitted to the official
list of the UKLA and to trading on the LSE or one Shire ADS quoted on NASDAQ (at
the option of the holder as indicated to the Transfer Agent) for each
Exchangeable Share presented and surrendered by the holder, together with, on
the payment date therefor, the full amount of all declared and unpaid dividends
on any such Exchangeable Share held by such holder on any dividend record date
which occurred prior to the Retraction Date (the "Retraction Price"). To effect
such redemption, the holder shall present and surrender at the registered office
of the Corporation or at any office of the Transfer Agent as may be specified by
the Corporation by notice to the holders of Exchangeable Shares the certificate
or certificates representing the Exchangeable Shares which the holder desires to
have the Corporation redeem, together with such other documents and instruments
as are required to effect a transfer of Exchangeable Shares under the CBCA and
the by-laws of the Corporation and such additional documents and instruments as
the Transfer Agent or the Corporation may reasonably require, and together with
a duly executed statement (the "Retraction Request") in the form of Schedule A
hereto or in such other form as may be acceptable to the Corporation:

    (a) specifying that the holder desires to have all or any number specified
       therein of the Exchangeable Shares represented by such certificate or
       certificates (the "Retracted Shares") redeemed by the Corporation;

    (b) stating the Business Day on which the holder desires to have the
       Corporation redeem the Retracted Shares (the "Retraction Date"), provided
       that the Retraction Date shall be not less than 10 Business Days nor more
       than 15 Business Days after the date on which the Retraction Request is
       received by the Corporation and further provided that, in the event that
       no such Business Day is specified by the holder in the Retraction
       Request, the Retraction Date shall be deemed to be the 15th Business Day
       after the date on which the Retraction Request is received by the
       Corporation; and

                                       26
<PAGE>
    (c) acknowledging the overriding right (the "Retraction Call Right") of
       CallCo to purchase all but not less than all the Retracted Shares
       directly from the holder and that the Retraction Request shall be deemed
       to be a revocable offer by the holder to sell the Retracted Shares to
       CallCo in accordance with the Retraction Call Right on the terms and
       conditions set out in Section 6.3 below.

6.2   Subject to the exercise by CallCo of the Retraction Call Right and to
Section 6.8, upon receipt by the Corporation or the Transfer Agent in the manner
specified in Section 6.1 hereof of a certificate or certificates representing
the number of Exchangeable Shares which the holder desires to have the
Corporation redeem, together with a Retraction Request and such other documents
and instruments as are required to effect a transfer of Exchangeable Shares
under the CBCA and the by-laws of the Corporation and such additional documents
and instruments as the Transfer Agent or the Corporation may reasonably require,
and provided that the Retraction Request is not revoked by the holder in the
manner specified in Section 6.7, the Corporation shall redeem the Retracted
Shares effective at the close of business on the Retraction Date and shall cause
to be delivered to such holder the Total Retraction Price with respect to such
shares, provided that all declared and unpaid dividends for which the record
date has occurred prior to the Retraction Date shall be paid on the payment date
for such dividends. If only a part of the Exchangeable Shares represented by any
certificate is redeemed (or purchased by CallCo pursuant to the Retraction Call
Right), a new certificate for the balance of such Exchangeable Shares shall be
issued to the holder at the expense of the Corporation.

6.3   Upon receipt by the Corporation of a Retraction Request, the Corporation
shall immediately notify CallCo thereof and shall provide to CallCo a copy of
the Retraction Request. In order to exercise the Retraction Call Right, CallCo
must notify the Corporation of its determination to do so (the "CallCo Call
Notice") within five Business Days of notification to CallCo by the Corporation
of the receipt by the Corporation of the Retraction Request. If CallCo does not
so notify the Corporation within such five Business Day period, the Corporation
will notify the holder as soon as possible thereafter that CallCo will not
exercise the Retraction Call Right. If CallCo delivers the CallCo Call Notice
within such five Business Day period, and provided that the Retraction Request
is not revoked by the holder in the manner specified in Section 6.7, the
Retraction Request shall thereupon be considered only to be an offer by the
holder to sell the Retracted Shares to CallCo in accordance with the Retraction
Call Right. In such event, the Corporation shall not redeem the Retracted Shares
and CallCo shall purchase from such holder and such holder shall sell to CallCo
on the Retraction Date the Retracted Shares for a purchase price (the "Purchase
Price") per share equal to the Retraction Price per share which shall be
satisfied in full by CallCo causing to be delivered to such holder three Shire
Ordinary Shares or one Shire ADS (at the option of the holder as indicated to
the Transfer Agent) for each Exchangeable Share presented and surrendered by the
holder, plus, on the designated payment date therefor, to the extent not paid by
the Corporation on the designated payment date therefor, an additional amount
equivalent to the full amount of all declared and unpaid dividends on those
Retracted Shares held by such holder on any dividend record date which occurred
prior to the Retraction Date (the "Dividend Amount"). For the purposes of
completing a purchase pursuant to the Retraction Call Right, CallCo shall
deposit with the Transfer Agent, on or before the Retraction Date, certificates
representing Shire Ordinary Shares and/or Share ADSs and a cheque or cheques of
CallCo payable at par at any branch of the bankers of CallCo representing the
aggregate Dividend Amount, less any amounts withheld on account of tax required
to be deducted and withheld therefrom. Provided that CallCo has complied with
the immediately preceding sentence, the closing of the purchase and sale of the
Retracted Shares pursuant to the Retraction Call Right shall be deemed to have
occurred as at the close of business on the Retraction Date and, for greater
certainty, no redemption by the Corporation of such Retracted Shares shall take
place on the Retraction Date. In the event that CallCo does not deliver a CallCo
Call Notice within such five Business Day period, and provided that the
Retraction Request is not revoked by the holder in the manner specified in
Section 6.7, the Corporation shall redeem the Retracted Shares on the Retraction
Date and in the manner otherwise contemplated in this Article 6.

                                       27
<PAGE>
6.4   The Corporation or CallCo, as the case may be, shall deliver or cause the
Transfer Agent to deliver to the relevant holder, at the address of the holder
recorded in the securities register of the Corporation for the Exchangeable
Shares or at the address specified in the holder's Retraction Request or by
holding for pick-up by the holder at the registered office of the Corporation or
at any office of the Transfer Agent as may be specified by the Corporation by
notice to the holders of Exchangeable Shares, certificates representing the
Shire Ordinary Shares (or effect the necessary CREST or other electronic
transfers) (which shares shall be duly issued as fully paid and non-assessable
and shall be free and clear of any lien, claim or encumbrance and shall be
admitted to the official list of the UKLA and to trading on the LSE) and/or
Shire ADSs (which securities shall be duly issued as fully paid and
non-assessable and shall be free and clear of any lien, claim or encumbrance and
shall be quoted on NASDAQ) registered in the name of the holder or in such other
name as the holder may request, and, if applicable and on or before the payment
date therefor, a cheque payable at par at any branch of the bankers of the
Corporation or CallCo, as applicable, representing the aggregate Dividend Amount
in payment of the Total Retraction Price or the Total Purchase Price, as the
case may be, in each case, less any amounts withheld on account of tax required
to be deducted and withheld therefrom, and such delivery of such certificates
(or necessary CREST or other electronic transfers) and cheques on behalf of the
Corporation or by CallCo, as the case may be, or by the Transfer Agent shall be
deemed to be payment of and shall satisfy and discharge all liability for the
Total Retraction Price or Total Purchase Price, as the case may be, to the
extent that the same is represented by such share certificates (or necessary
CREST or other electronic transfers) and cheques (plus any tax deducted and
withheld therefrom and remitted to the proper tax authority).

6.5   On and after the close of business on the Retraction Date, the holder of
the Retracted Shares shall cease to be a holder of such Retracted Shares and
shall not be entitled to exercise any of the rights of a holder in respect
thereof, other than the right to receive the Total Retraction Price or Total
Purchase Price, as the case may be, unless upon presentation and surrender of
certificates in accordance with the foregoing provisions, payment of the Total
Retraction Price or the Total Purchase Price, as the case may be, shall not be
made as provided in Section 6.4, in which case the rights of such holder shall
remain unaffected until the Total Retraction Price or the Total Purchase Price,
as the case may be, has been paid in the manner hereinbefore provided. On and
after the close of business on the Retraction Date, provided that presentation
and surrender of certificates and payment of the Total Retraction Price or the
Total Purchase Price, as the case may be, has been made in accordance with the
foregoing provisions, the holder of the Retracted Shares so redeemed by the
Corporation or purchased by CallCo shall thereafter be considered and deemed for
all purposes to be a holder of the Shire Ordinary Shares and/or Shire ADSs
delivered to it.

6.6   Notwithstanding any other provision of this Article 6, the Corporation
shall not be obligated to redeem Retracted Shares specified by a holder in a
Retraction Request to the extent that such redemption of Retracted Shares would
be contrary to solvency requirements or other provisions of applicable law. If
the Corporation believes that on any Retraction Date it would not be permitted
by any of such provisions to redeem the Retracted Shares tendered for redemption
on such date, and provided that CallCo shall not have exercised the Retraction
Call Right with respect to the Retracted Shares, the Corporation shall only be
obligated to redeem Retracted Shares specified by a holder in a Retraction
Request to the extent of the maximum number that may be so redeemed (rounded
down to a whole number of shares) as would not be contrary to such provisions
and shall notify the holder at least two Business Days prior to the Retraction
Date as to the number of Retracted Shares which will not be redeemed by the
Corporation. In any case in which the redemption by the Corporation of Retracted
Shares would be contrary to solvency requirements or other provisions of
applicable law, the Corporation shall redeem the maximum number of Exchangeable
Shares which the Board of Directors determine the Corporation is, on the
Retraction Date, permitted to redeem, which shall be selected as nearly as may
be pro rata (rounded up to a whole number of shares) in proportion to the total
number of Exchangeable Shares tendered for retraction by each holder thereof and
the Corporation shall issue to each holder of Retracted Shares a new
certificate, at the expense of the Corporation, representing the Retracted
Shares not redeemed by the Corporation pursuant to Section 6.2 hereof. Provided
that the Retraction Request is not revoked by the holder in the manner specified
in

                                       28
<PAGE>
Section 6.7, the holder of any such Retracted Shares not redeemed by the
Corporation pursuant to Section 6.2 of these share provisions as a result of
solvency requirements or other provisions of applicable law shall be deemed by
giving the Retraction Request to have instructed the Trustee to require Shire to
purchase such Retracted Shares from such holder on the Retraction Date or as
soon as practicable thereafter on payment by to such holder of the Purchase
Price for each such Retracted Share, all as more specifically provided in
Section 5.7 of the Voting and Exchange Trust Agreement.

6.7   A holder of Retracted Shares may, by notice in writing given by the holder
to the Corporation before the close of business on the Business Day immediately
preceding the Retraction Date, withdraw its Retraction Request, in which event
such Retraction Request shall be null and void and, for greater certainty, the
revocable offer constituted by the Retraction Request to sell the Retracted
Shares to CallCo shall be deemed to have been revoked.

6.8   The Corporation, by issuing a press release, may at any time and from time
to time notify the holders of Exchangeable Shares of the suspension of their
rights to require the Corporation to redeem any Exchangeable Shares for Shire
Ordinary Shares pursuant to this Section 6 if Shire has been unable to obtain
the approval of the UKLA or the LSE to the admission of the Shire Ordinary
Shares to the official list of the UKLA or to trading on the LSE that would be
required to be delivered to the holders of Exchangeable Shares in connection
with the exercise of such rights and such rights shall be suspended until such
approval has been obtained. The Corporation shall notify the holders of the
Exchangeable Shares by press release, that such rights are once again in force
forthwith after such approval has been obtained.

                                   ARTICLE 7
              REDEMPTION OF EXCHANGEABLE SHARES BY THE CORPORATION

7.1   Subject to applicable law, and provided CallCo has not exercised the
Redemption Call Right, the Corporation shall on the Redemption Date redeem all
but not less than all of the then outstanding Exchangeable Shares for an amount
per share equal to the Current Market Price of a Shire Ordinary Share on the
last Business Day prior to the Redemption Date multiplied by three, which shall
be satisfied in full by the Corporation causing to be delivered to each holder
of Exchangeable Shares three Shire Ordinary Shares admitted to the official list
of the UKLA and to trading on the LSE or one Shire ADS quoted on NASDAQ (at the
option of the holder as indicated to the Transfer Agent) for each Exchangeable
Share held by such holder, together with the full amount of all declared and
unpaid dividends on each such Exchangeable Share held by such holder on any
dividend record date which occurred prior to the Redemption Date (the
"Redemption Price").

7.2   In any case of a redemption of Exchangeable Shares under this Article 7,
the Corporation shall, at least 60 days before the Redemption Date (other than a
Redemption Date established in connection with a Shire Control Transaction, an
Exchangeable Share Voting Event or an Exempt Exchangeable Share Voting Event),
send or cause to be sent to each holder of Exchangeable Shares a notice in
writing of the redemption by the Corporation or the purchase by CallCo under the
Redemption Call Right, as the case may be, of the Exchangeable Shares held by
such holder; provided that if the notice period of 60 days would expire after
the date that would, but for such 60-day period, be established as the
Redemption Date, then the Redemption Date will be deferred until the notice
period of 60 days has passed. In the case of a Redemption Date established in
connection with a Shire Control Transaction, an Exchangeable Share Voting Event
or an Exempt Exchangeable Share Voting Event, the written notice of redemption
by the Corporation or the purchase by CallCo under the Redemption Call Right
will be sent on or before the Redemption Date, on as many days prior written
notice as may be determined by the Board of Directors of the Corporation to be
reasonably practicable in the circumstances. In any such case, such notice shall
set out the Redemption Price or the Redemption Call Purchase Price, as the case
may be, the Redemption Date and, if applicable, particulars of the Redemption
Call Right.

                                       29
<PAGE>
7.3   On or after the Redemption Date and subject to the exercise by CallCo of
the Redemption Call Right, the Corporation shall cause to be delivered to the
holders of the Exchangeable Shares to be redeemed the Redemption Price for each
such Exchangeable Share, together with the full amount of all declared and
unpaid dividends on each such Exchangeable Share held by such holder on any
dividend record date which occurred prior to the Redemption Date, upon
presentation and surrender at the registered office of the Corporation or at any
office of the Transfer Agent or the Corporation as may be specified by the
Corporation in such notice of the certificates representing such Exchangeable
Shares, together with such other documents and instruments as may be required to
effect a transfer of Exchangeable Shares under the CBCA and the by-laws of the
Corporation and such additional documents and instruments as the Transfer Agent,
Shire or the Corporation may reasonably require. Payment of the Total Redemption
Price for such Exchangeable Shares, together with payment of such dividends,
shall be made by delivery to each holder, at the address of the holder recorded
in the securities register of the Corporation or by holding for pick-up by the
holder at the registered office of the Corporation or at any office of the
Transfer Agent as may be specified by the Corporation in such notice, on behalf
of the Corporation of certificates representing Shire Ordinary Shares and/or
Shire ADSs (or effecting the necessary CREST or other electronic transfer)
(which shares shall be duly issued as fully paid and non-assessable and shall be
free and clear of any lien, claim or encumbrance) and, if applicable, a cheque
of the Corporation payable at par at any branch of the bankers of the
Corporation in payment of any such dividends, in each case, less any amounts
withheld on account of tax required to be deducted and withheld therefrom. On
and after the Redemption Date, the holders of the Exchangeable Shares called for
redemption shall cease to be holders of such Exchangeable Shares and shall not
be entitled to exercise any of the rights of holders in respect thereof, other
than the right to receive the Total Redemption Price and any such dividends,
unless payment of the Total Redemption Price and any such dividends for such
Exchangeable Shares shall not be made upon presentation and surrender of
certificates in accordance with the foregoing provisions, in which case the
rights of the holders shall remain unaffected until the Total Redemption Price
and any such dividends have been paid in the manner hereinbefore provided. The
Corporation shall have the right at any time after the sending of notice of its
intention to redeem the Exchangeable Shares as aforesaid to deposit or cause to
be deposited the Total Redemption Price for, and the full amount of such
dividends on (except as provided in the preceding sentence), the Exchangeable
Shares so called for redemption, or of such of the said Exchangeable Shares
represented by certificates that have not at the date of such deposit been
surrendered by the holders thereof in connection with such redemption, in a
custodial account with any chartered bank or trust company in Canada named in
such notice, less any amounts withheld on account of tax required to be deducted
and withheld therefrom. Upon the later of such deposit being made and the
Redemption Date, the Exchangeable Shares in respect whereof such deposit shall
have been made shall be redeemed and the rights of the holders thereof after
such deposit or Redemption Date, as the case may be, shall be limited to
receiving the Total Redemption Price and such dividends for such Exchangeable
Shares so deposited, against presentation and surrender of the said certificates
held by them, respectively, in accordance with the foregoing provisions. Upon
such payment or deposit of the Total Redemption Price and the full amount of
such dividends, the holders of the Exchangeable Shares shall thereafter be
considered and deemed for all purposes to be holders of the Shire Ordinary
Shares and/or Shire ADSs delivered to them or the custodian on their behalf.

                                   ARTICLE 8
                                 VOTING RIGHTS

8.1   Except as required by applicable law and by Article 10 hereof, the holders
of the Exchangeable Shares shall not be entitled as such to receive notice of or
to attend any meeting of the shareholders of the Corporation or to vote at any
such meeting.

                                       30
<PAGE>
                                   ARTICLE 9
                             AMENDMENT AND APPROVAL

9.1   The rights, privileges, restrictions and conditions attaching to the
Exchangeable Shares may be added to, changed or removed but only with the
approval of the holders of the Exchangeable Shares given as hereinafter
specified.

9.2   Any approval given by the holders of the Exchangeable Shares to add to,
change or remove any right, privilege, restriction or condition attaching to the
Exchangeable Shares or any other matter requiring the approval or consent of the
holders of the Exchangeable Shares shall be deemed to have been sufficiently
given if it shall have been given in accordance with applicable law subject to a
minimum requirement that such approval be evidenced by resolution passed by not
less than two-thirds of the votes cast on such resolution at a meeting of
holders of Exchangeable Shares duly called and held at which the holders of at
least 25% of the outstanding Exchangeable Shares at that time are present or
represented by proxy; provided that if at any such meeting the holders of at
least 25% of the outstanding Exchangeable Shares at that time are not present or
represented by proxy within one-half hour after the time appointed for such
meeting, then the meeting shall be adjourned to such date not less than five
days thereafter and to such time and place as may be designated by the Chairman
of such meeting. At such adjourned meeting the holders of Exchangeable Shares
present or represented by proxy thereat may transact the business for which the
meeting was originally called and a resolution passed thereat by the affirmative
vote of not less than two-thirds of the votes cast on such resolution at such
meeting shall constitute the approval or consent of the holders of the
Exchangeable Shares.

                                   ARTICLE 10
                            RECIPROCAL CHANGES, ETC.
                      IN RESPECT OF SHIRE ORDINARY SHARES

10.1   Each holder of an Exchangeable Share acknowledges that the Exchangeable
Share Support Agreement provides, in part, that Shire will not without the prior
approval of the Corporation and the prior approval of the holders of the
Exchangeable Shares given in accordance with Section 9.2 of these share
provisions:

    (a) issue or distribute Shire Ordinary Shares (or securities exchangeable
       for or convertible into or carrying rights to acquire Shire Ordinary
       Shares) to the holders of all or substantially all of the then
       outstanding Shire Ordinary Shares by way of share dividend or other
       distribution, other than an issue of Shire Ordinary Shares (or securities
       exchangeable for or convertible into or carrying rights to acquire Shire
       Ordinary Shares) to holders of Shire Ordinary Shares who exercise an
       option to receive dividends in Shire Ordinary Shares (or securities
       exchangeable for or convertible into or carrying rights to acquire Shire
       Ordinary Shares) in lieu of receiving cash dividends;

    (b) issue or distribute rights, options or warrants to the holders of all or
       substantially all of the then outstanding Shire Ordinary Shares entitling
       them to subscribe for or to purchase Shire Ordinary Shares (or securities
       exchangeable for or convertible into or carrying rights to acquire Shire
       Ordinary Shares); or

    (c) issue or distribute to the holders of all or substantially all of the
       then outstanding Shire Ordinary Shares:

        (i) shares or securities of Shire of any class other than Shire Ordinary
            Shares (other than shares convertible into or exchangeable for or
            carrying rights to acquire Shire Ordinary Shares);

        (ii) rights, options or warrants other than those referred to in
             Section 10.1(b) above;

                                       31
<PAGE>
       (iii) evidences of indebtedness of Shire; or

        (iv) assets of Shire,

unless the economic equivalent on a per share basis of such rights, options,
securities, shares, evidences of indebtedness or other assets is issued or
distributed simultaneously to holders of the Exchangeable Shares.

10.2   Each holder of an Exchangeable Share acknowledges that the Exchangeable
Share Support Agreement further provides, in part, that Shire will not without
the prior approval of the Corporation and the prior approval of the holders of
the Exchangeable Shares given in accordance with Section 9.2 of these share
provisions:

    (a) subdivide, redivide or change the then outstanding Shire Ordinary Shares
       into a greater number of Shire Ordinary Shares;

    (b) reduce, combine, consolidate or change the then outstanding Shire
       Ordinary Shares into a lesser number of Shire Ordinary Shares; or

    (c) reclassify or otherwise change the Shire Ordinary Shares or effect an
       amalgamation, merger, reorganization or other transaction affecting the
       Shire Ordinary Shares,

unless the same or an economically equivalent change shall simultaneously be
made to, or in, the rights of the holders of the Exchangeable Shares. The
Exchangeable Share Support Agreement further provides, in part, that the
aforesaid provisions of the Exchangeable Share Support Agreement shall not be
changed without the approval of the holders of the Exchangeable Shares given in
accordance with Section 9.2 of these share provisions.

                                   ARTICLE 11
               ACTIONS BY THE CORPORATION UNDER SUPPORT AGREEMENT

11.1   The Corporation will take all such actions and do all such things as
shall be necessary or advisable to perform and comply with and to ensure
performance and compliance by Shire, CallCo and the Corporation with all
provisions of the Exchangeable Share Support Agreement applicable to Shire,
CallCo and the Corporation, respectively, in accordance with the terms thereof
including, without limitation, taking all such actions and doing all such things
as shall be necessary or advisable to enforce to the fullest extent possible for
the direct benefit of the Corporation all rights and benefits in favour of the
Corporation under or pursuant to such agreement.

11.2   The Corporation shall not propose, agree to or otherwise give effect to
any amendment to, or waiver or forgiveness of its rights or obligations under,
the Exchangeable Share Support Agreement without the approval of the holders of
the Exchangeable Shares given in accordance with Section 9.2 of these share
provisions other than such amendments, waivers and/or forgiveness as may be
necessary or advisable for the purposes of:

    (a) adding to the covenants of the other parties to such agreement for the
       protection of the Corporation or the holders of the Exchangeable Shares
       thereunder;

    (b) making such provisions or modifications not inconsistent with such
       agreement as may be necessary or desirable with respect to matters or
       questions arising thereunder which, in the good faith opinion of the
       Board of Directors, it may be expedient to make, provided that the Board
       of Directors shall be of the good faith opinion, after consultation with
       counsel, that such provisions and modifications will not be prejudicial
       to the interests of the holders of the Exchangeable Shares; or

    (c) making such changes in or corrections to such agreement which, on the
       advice of counsel to the Corporation, are required for the purpose of
       curing or correcting any ambiguity or defect or

                                       32
<PAGE>
       inconsistent provision or clerical omission or mistake or manifest error
       contained therein, provided that the Board of Directors shall be of the
       good faith opinion, after consultation with counsel, that such changes or
       corrections will not be prejudicial to the interests of the holders of
       the Exchangeable Shares.

                                   ARTICLE 12
                              LEGEND; CALL RIGHTS

12.1   The certificates evidencing the Exchangeable Shares shall contain or have
affixed thereto a legend in form and on terms approved by the Board of
Directors, with respect to the Exchangeable Share Support Agreement, the
provisions of the Plan of Arrangement relating to the Liquidation Call Right,
the Redemption Call Right and the Shire Call Right, and the Voting and Exchange
Trust Agreement (including the provisions with respect to the voting rights,
exchange right and automatic exchange thereunder).

12.2   Each holder of an Exchangeable Share, whether of record or beneficial, by
virtue of becoming and being such a holder shall be deemed to acknowledge each
of the Liquidation Call Right, the Retraction Call Right and the Redemption Call
Right, in each case, in favour of CallCo, and the overriding nature thereof in
connection with the liquidation, dissolution or winding-up of the Corporation or
the retraction or redemption of Exchangeable Shares, as the case may be, and the
Shire Call Right in favour of Shire and to be bound thereby in favour of CallCo
or Shire, as the case may be, as therein provided.

                                   ARTICLE 13
                                    NOTICES

13.1   Any notice, request or other communication to be given to the Corporation
by a holder of Exchangeable Shares shall be in writing and shall be valid and
effective if given by mail (postage prepaid) or by telecopy or by delivery to
the registered office of the Corporation and addressed to the attention of the
President. Any such notice, request or other communication, if given by mail,
telecopy or delivery, shall only be deemed to have been given and received upon
actual receipt thereof by the Corporation.

13.2   Any presentation and surrender by a holder of Exchangeable Shares to the
Corporation or the Transfer Agent of certificates representing Exchangeable
Shares in connection with the liquidation, dissolution or winding-up of the
Corporation or the retraction or redemption of Exchangeable Shares shall be made
by registered mail (postage prepaid) or by delivery to the registered office of
the Corporation or to such office of the Transfer Agent as may be specified by
the Corporation, in each case, addressed to the attention of the President of
the Corporation. Any such presentation and surrender of certificates shall only
be deemed to have been made and to be effective upon actual receipt thereof by
the Corporation or the Transfer Agent, as the case may be. Any such presentation
and surrender of certificates made by registered mail shall be at the sole risk
of the holder mailing the same.

13.3   Any notice, request or other communication to be given to a holder of
Exchangeable Shares by or on behalf of the Corporation shall be in writing and
shall be valid and effective if given by mail (postage prepaid) or by delivery
to the address of the holder recorded in the securities register of the
Corporation or, in the event of the address of any such holder not being so
recorded, then at the last known address of such holder. Any such notice,
request or other communication, if given by mail, shall be deemed to have been
given and received on the third Business Day following the date of mailing and,
if given by delivery, shall be deemed to have been given and received on the
date of delivery. Accidental failure or omission to give any notice, request or
other communication to one or more holders of Exchangeable Shares shall not
invalidate or otherwise alter or affect any action or proceeding to be taken by
the Corporation pursuant thereto.

                                       33
<PAGE>
13.4   If the Corporation determines that mail service is or is threatened to be
interrupted at the time when the Corporation is required or elects to give any
notice to the holders of Exchangeable Shares hereunder, the Corporation shall,
notwithstanding the provisions hereof, give such notice by means of publication
in THE GLOBE AND MAIL, national edition, or any other English language daily
newspaper or newspapers of general circulation in Canada and in a French
language daily newspaper of general circulation in the Province of Quebec, once
in each of two successive weeks, and notice so published shall be deemed to have
been given on the latest date on which the first publication has taken place.

    If, by reason of any actual or threatened interruption of mail service due
to strike, lock-out or otherwise, any notice to be given to the Corporation
would be unlikely to reach its destination in a timely manner, such notice shall
be valid and effective only if delivered personally to the Corporation in
accordance with Section 13.1 or 13.2, as the case may be.

                                   ARTICLE 14
                               WITHHOLDING RIGHTS

14.1   The Corporation, CallCo, Shire and the Exchange Agent will be entitled to
deduct and withhold from any dividend or consideration otherwise payable to any
holder of Exchangeable Shares, such amounts as the Corporation, CallCo, Shire or
the Exchange Agent is required to deduct and withhold with respect to such
payment under the ITA, the United States INTERNAL REVENUE CODE OF 1986, the
United Kingdom tax laws or any provision of provincial, state, local or foreign
tax law, in each case, as amended. To the extent that amounts are so withheld,
such withheld amounts will be treated for all purposes hereof as having been
paid to the holder of the Exchangeable Shares in respect of which such deduction
and withholding was made, provided that such withheld amounts are actually
remitted to the appropriate tax authority. To the extent that the amount so
required to be deducted or withheld from any payment to a holder exceeds the
cash portion of the consideration otherwise payable to the holder, the
Corporation, CallCo, Shire and the Exchange Agent are hereby authorized to sell
or otherwise dispose of such portion of the consideration as is necessary to
provide sufficient funds to the Corporation, CallCo, Shire or the Exchange
Agent, as the case may be, to enable it to comply with such deduction or
withholding requirement and the Corporation, CallCo, Shire or the Exchange Agent
will notify the holder thereof and remit to the holder any unapplied balance of
the net proceeds of such sale. The Corporation shall not be entitled to withhold
amounts on dividends payable to holders of Exchangeable Shares pursuant to the
United States INTERNAL REVENUE CODE OF 1986 unless it has received an opinion
from counsel stating that such withholding is required under the INTERNAL
REVENUE CODE OF 1986.

                                   ARTICLE 15
                                   STAMP TAX

15.1 (a) Notwithstanding any other provision herein but subject to
         Section 15.1(b) below, holders of Exchangeable Shares or Persons to
         whom Exchangeable Shares are issued or transferred (in each case other
         than Shire, its Affiliates, the Transfer Agent or the Exchange Agent)
         shall be responsible for any and all Stamp Taxes payable in connection
         with the transfer, exchange, redemption or issuance of such shares or
         their exchange for Shire Ordinary Shares or Shire ADSs and, subject to
         Section 15.1(b) below, transferees of Shire Ordinary Shares or Shire
         ADSs or Persons to whom Shire Ordinary Shares or Shire ADSs are issued
         (in each case other than Shire, its Affiliates, the Transfer Agent or
         the Exchange Agent) shall be responsible for any and all Stamp Taxes
         payable in connection with the transfer or issuance of such securities.
         In no event, subject to Section 15.1(b) below, will Shire, its
         Affiliates, the Transfer Agent or the Exchange Agent be responsible for
         any Stamp Taxes and Shire, its Affiliates, the Transfer Agent and/or
         the Exchange Agent shall make such regulations and arrangements as are
         necessary to ensure that such holders, such transferees and such
         Persons pay all such applicable Stamp Taxes.

                                       34
<PAGE>
    (b) Shire shall be responsible for (i) any United Kingdom stamp duty reserve
       tax payable on the issue or transfer of Shire Ordinary Shares to a
       depository or to a nominee or agent for a depository pursuant to these
       share provisions, (ii) any United Kingdom stamp duty reserve tax that
       arises in respect of the transfer of Exchangeable Shares in exchange for
       Shire ADSs and/or Shire Ordinary Shares (an "Exchange"), (iii) any United
       Kingdom stamp duty reserve tax that Shire or any of its Affiliates
       requires to be paid on an Exchange, and (iv) any United Kingdom stamp
       duty payable on an issue of Exchangeable Shares to a holder of common
       shares of BioChem pursuant to these share provisions.

                                       35
<PAGE>
                                   SCHEDULE A
                              NOTICE OF RETRACTION

To Shire Acquisition Inc. (the "Corporation") and 3829359 Canada Inc.
("CallCo").

    This notice is given pursuant to Article 6 of the provisions (the "Share
Provisions") attaching to the Exchangeable Shares of the Corporation represented
by the attached certificate and all capitalized words and expressions used in
this notice that are defined in the Share Provisions have the meanings ascribed
to such words and expressions in such Share Provisions.

    The undersigned hereby notifies the Corporation that, subject to the
Retraction Call Right referred to below, the undersigned desires to have the
Corporation redeem in accordance with Article 6 of the Share Provisions:

   / / all share(s) represented by the attached share certificate; or

   / / ______________ share(s) only.

    The undersigned hereby notifies the Corporation that the Retraction Date
shall be _______________________________________________________________________

NOTE: The Retraction Date must be a Business Day and must not be less than 10
      Business Days nor more than 15 Business Days after the date upon which
      this notice is received by the Corporation. If no such Business Day is
      specified above, the Retraction Date shall be deemed to be the 15th
      Business Day after the date on which this notice is received by the
      Corporation.

    The undersigned acknowledges the overriding Retraction Call Right of CallCo
to purchase all but not less than all the Retracted Shares from the undersigned
and that this notice is and shall be deemed to be a revocable offer by the
undersigned to sell the Retracted Shares to CallCo in accordance with the
Retraction Call Right on the Retraction Date for the Purchase Price and on the
other terms and conditions set out in Section 6.3 of the Share Provisions. This
notice of retraction, and this offer to sell the Retracted Shares to CallCo, may
be revoked and withdrawn by the undersigned only by notice in writing given to
the Corporation at any time before the close of business on the Business Day
immediately preceding the Retraction Date.

    The undersigned acknowledges that if, as a result of solvency provisions of
applicable law, the Corporation is unable to redeem all Retracted Shares, and
provided that CallCo shall not have exercised the Retraction Call Right with
respect to the Retracted Shares, the undersigned will be deemed to have
exercised the Exchange Right (as defined in the Voting and Exchange Trust
Agreement) so as to require Shire to purchase the unredeemed Retracted Shares.

                                       36
<PAGE>
    The undersigned hereby represents and warrants to CallCo and the Corporation
that the undersigned:

   / / is

            (select one)

   / / is not

a non-resident of Canada for purposes of the INCOME TAX ACT (Canada). THE
UNDERSIGNED ACKNOWLEDGES THAT IN THE ABSENCE OF AN INDICATION THAT THE
UNDERSIGNED IS NOT A NON-RESIDENT OF CANADA, WITHHOLDING ON ACCOUNT OF CANADIAN
TAX MAY BE MADE IF THE RETRACTED SHARES ARE NOT LISTED ON A PRESCRIBED STOCK
EXCHANGE FOR THE PURPOSES OF THE INCOME TAX ACT (CANADA), FROM AMOUNTS PAYABLE
TO THE UNDERSIGNED ON THE REDEMPTION OR PURCHASE OF THE RETRACTED SHARES.

    The undersigned hereby represents and warrants to CallCo, the Corporation
and Shire that the undersigned has good title to, and owns, the share(s)
represented by this certificate to be acquired by CallCo or the Corporation, as
the case may be, free and clear of all liens, claims and encumbrances.

<TABLE>
<S>                            <C>                            <C>
           (Date)               (Signature of Shareholder)      (Guarantee of Signature)
</TABLE>

   / / Please check box if the securities and any cheque(s) resulting from the
      retraction or purchase of the Retracted Shares are to be held for pick-up
       by the shareholder from the Transfer Agent, failing which the securities
       and any cheque(s) will be mailed to the last address of the shareholder
       as it appears on the register.

NOTE: This panel must be completed and the attached share certificate, together
      with such additional documents as the Transfer Agent may require, must be
      deposited with the Corporation or the Transfer Agent. The securities and
      any cheque(s) resulting from the retraction or purchase of the Retracted
      Shares will be issued and registered in, and made payable to,
      respectively, the name of the shareholder as it appears on the register of
      the Corporation and the securities and any cheque(s) resulting from such
      retraction or purchase will be delivered to such shareholder as indicated
      above, unless the form appearing immediately below is duly completed.

Date: ____________________________________

Name of Person in Whose Name Securities or Cheque(s)

Are to be Registered, Issued or Delivered (please print): ______________________

Street Address or P.O. Box: ____________________________________________________

Signature of Shareholder: ______________________________________________________

City, Province and Postal Code: ________________________________________________

Signature Guaranteed by: _______________________________________________________

NOTE: If this notice of retraction is for less than all of the shares
      represented by the attached certificate, a certificate representing the
      remaining share(s) of the Corporation represented by the attached share
      certificate will be issued and registered in the name of the shareholder
      as it appears on the register of the Corporation, unless the Share
      Transfer Power on the share certificate is duly completed in respect of
      such share(s).

                                       37