Document:

<PAGE>
                                                                    Exhibit 4.51

                               DATED June 7, 2005

               (1)  MITEL NETWORK HOLDINGS LIMITED
                    as Chargor

               (2)  HIGHBRIDGE INTERNATIONAL, LLC
                    as Security Agent

                                   ----------
                                  SHARE CHARGE
                                   ----------

                                Speechly Bircham
                               6 St Andrew Street
                                     London
                                    EC4A 3LX
                                Doc No. 1130720-3

<PAGE>
                               TABLE OF CONTENTS

<Table>
<Caption>
                                                                           PAGE
<S>  <C>                                                                   <C>
 1.  DEFINITIONS AND INTERPRETATION                                           2
 2.  CLAWBACK                                                                 5
 3.  FIXED CHARGE                                                             6
 4.  REPRESENTATIONS AND WARRANTIES                                           6
 5.  VOTING RIGHTS                                                            7
 6.  DIVIDENDS AND OTHER DISTRIBUTIONS                                        7
 7.  COVENANTS                                                                7
 8.  POWERS OF THE SECURITY TRUSTEE                                           8
 9.  PROVISIONS AS TO SECURITY                                                9
10.  ENFORCEABILITY                                                          10
11.  ENFORCEMENT OF SECURITY                                                 10
12.  APPLICATION OF PROCEEDS                                                 11
13.  POWER OF ATTORNEY                                                       12
14.  NEW ACCOUNTS                                                            13
15.  SUSPENSE ACCOUNTS                                                       13
16.  SET OFF                                                                 14
17.  TRANSFERS                                                               15
18.  RELEASE OF SECURITY                                                     15
19.  MISCELLANEOUS                                                           15
20.  NOTICES                                                                 17
21.  GOVERNING LAW                                                           17
22.  JURISDICTION                                                            17
23.  RELATIONSHIP WITH SECURITIES PURCHASE AGREEMENT--OVERRIDING PROVISIONS  18
</Table>

                                       1
<PAGE>

THIS SHARE CHARGE IS MADE BY WAY OF DEED ON                        2005

BETWEEN:

(1)  MITEL NETWORK HOLDINGS LIMITED A PRIVATE COMPANY LIMITED BY SHARES
     INCORPORATED IN ENGLAND AND WALES UNDER NUMBER 1309629 WHOSE REGISTERED
     OFFICE IS AT MITEL BUSINESS PARK, PORTSKEWETT, CALDICOT, GWENT NP26 5YR
     (THE "CHARGOR"); AND

(2)  HIGHBRIDGE INTERNATIONAL, LLC (THE "SECURITY AGENT" AS SECURITY TRUSTEE FOR
     ITSELF AND THE OTHER SECURED PARTIES).

RECITALS:

(A)  THE SECURITY AGENT HAS ENTERED INTO THE SECURITIES PURCHASE AGREEMENT AND
     THE NOTES (EACH AS DEFINED BELOW) WITH, INTER ALIA, THE BORROWER.

(B)  IT IS A CONDITION OF THE SECURITIES PURCHASE AGREEMENT AND THE NOTES THAT
     THE CHARGOR ENTERS INTO THIS SHARE CHARGE.

(C)  IT IS INTENDED BY THE PARTIES TO THIS SHARE CHARGE THAT THIS DOCUMENT WILL
     TAKE EFFECT AS A DEED DESPITE THE FACT THAT A PARTY MAY ONLY EXECUTE THIS
     SHARE CHARGE UNDER HAND.

NOW THE DEBENTURE WITNESSES AS FOLLOWS:

1.   DEFINITIONS AND INTERPRETATION

1.1  DEFINITIONS

     TERMS DEFINED IN THE SECURITIES PURCHASE AGREEMENT AND/OR THE NOTES SHALL,
     SAVE AS OTHERWISE EXPRESSLY PROVIDED HEREIN, HAVE THE SAME MEANING OR
     CONSTRUCTION IN THIS SHARE CHARGE AND IN ADDITION:

     "BORROWER" MEANS MITEL NETWORKS CORPORATION, A CORPORATION INCORPORATED
     UNDER THE LAWS OF CANADA.

     "COLLATERAL" MEANS THE SHARES AND THE DERIVATIVE ASSETS.

                                       2
<PAGE>
     "COLLATERAL AGENCY AGREEMENT" MEANS THE COLLATERAL AGENCY AGREEMENT DATED
     ON OR ABOUT THE DATE HEREOF BETWEEN, AMONG OTHERS, THE SECURITY AGENT, THE
     BORROWER AND THE NOTEHOLDERS (AS DEFINED THEREIN);

     "DERIVATIVE ASSETS" MEANS ALL ASSETS DERIVING FROM THE SHARES INCLUDING ALL
     ALLOTMENTS, ACCRETIONS, OFFERS, RIGHTS, DIVIDENDS, DISTRIBUTIONS, INTEREST,
     BENEFITS AND ADVANTAGES WHATSOEVER AT ANY TIME ACCRUING, OFFERED OR ARISING
     IN RESPECT OF OR INCIDENTAL TO THE SHARES AND ALL STOCK, SHARES, RIGHTS,
     MONEY OR PROPERTY ACCRUING OR OFFERED AT ANY TIME BY WAY OF CONVERSION,
     REDEMPTION, BONUS, PREFERENCE, EXCHANGE, PURCHASE, SUBSTITUTION, OPTION
     RIGHTS OR OTHERWISE.

     "EVENT OF DEFAULT" MEANS THE OCCURRENCE OF AN EVENT OF DEFAULT (HOWSOEVER
     DESCRIBED) UNDER ANY OF THE TRANSACTION DOCUMENTS AND/OR THE FAILURE OF THE
     CHARGOR TO COMPLY WITH ANY OF ITS OBLIGATIONS UNDER THIS SHARE CHARGE.

     "NOTES" MEANS THE SENIOR SECURED CONVERTIBLE LOAN NOTES ISSUED PURSUANT TO
     THE SECURITIES PURCHASE AGREEMENT.

     "SECURITIES PURCHASE AGREEMENT" MEANS THE SECURITIES PURCHASE AGREEMENT
     AMONG THE BORROWER, THE SECURITY AGENT AND THE OTHER PARTIES REFERRED TO
     THEREIN AS "BUYERS" MADE OR TO BE MADE ON OR ABOUT THE DATE OF THIS SHARE
     CHARGE.

     "SECURED OBLIGATIONS" MEANS ALL PRESENT AND FUTURE OBLIGATIONS AND
     LIABILITIES (WHETHER ACTUAL OR CONTINGENT, WHETHER OWED JOINTLY, SEVERALLY
     OR IN ANY OTHER CAPACITY WHATSOEVER AND WHETHER ORIGINALLY INCURRED BY THE
     BORROWER OR BY SOME OTHER PERSON) OF THE BORROWER WHICH ARE NOW OR MAY AT
     ANY TIME HEREAFTER BE DUE, OWING OR PAYABLE, OR EXPRESSED TO BE DUE, OWING
     OR PAYABLE TO THE SECURITY AGENT UNDER EACH OF THE TRANSACTION DOCUMENTS.

     "SECURED PARTIES" MEANS THE SECURITY AGENT AND THE BUYERS FROM TIME TO TIME
     UNDER THE SECURITIES PURCHASE AGREEMENT, AND "SECURED PARTY" MEANS ANY OF
     THEM.

     "SECURITY" INCLUDES ANY MORTGAGE, FIXED OR FLOATING CHARGE, ENCUMBRANCE,
     LIEN, PLEDGE, HYPOTHECATION, ASSIGNMENT BY WAY OF SECURITY, OR TITLE
     RETENTION ARRANGEMENT (OTHER THAN IN RESPECT OF GOODS PURCHASED IN THE
     ORDINARY COURSE OF TRADING), AND ANY AGREEMENT OR ARRANGEMENT HAVING
     SUBSTANTIALLY THE SAME ECONOMIC OR FINANCIAL EFFECT AS ANY OF THE FOREGOING
     (INCLUDING ANY "HOLD BACK" OR "FLAWED ASSET" ARRANGEMENT).

                                       3
<PAGE>
     "SECURITY PERIOD" MEANS THE PERIOD BEGINNING ON THE DATE OF THIS SHARE
     CHARGE AND ENDING ON THE DATE ON WHICH THE SECURED OBLIGATIONS HAVE
     IRREVOCABLY BEEN PAID OR DISCHARGED IN FULL.

     "SHARES" MEANS THE 73,816,467 ORDINARY FULLY PAID UP SHARES OF POUND
     STERLING1.00 EACH IN MITEL NETWORKS LIMITED, REPRESENTING 100% OF THE
     ENTIRE ISSUED ORDINARY SHARE CAPITAL OF MITEL NETWORKS LIMITED REGISTERED
     IN THE NAME OF THE CHARGOR AT THE DATE HEREOF, AND ALL OTHER SHARES IN
     MITEL NETWORKS LIMITED OWNED BY THE CHARGOR AT ANY TIME DURING THE SECURITY
     PERIOD.

     "TRANSACTION DOCUMENTS" MEANS THE SECURITIES PURCHASE AGREEMENT, THE NOTES,
     THE SECURITY DOCUMENTS (AS DEFINED IN THE NOTES), THE COLLATERAL AGENCY
     AGREEMENT AND THE REGISTRATION RIGHTS AGREEMENT (AS DEFINED IN THE NOTES).

1.2  INTERPRETATION

     IN THIS SHARE CHARGE, UNLESS OTHERWISE SPECIFIED:

     (A)  REFERENCES TO CLAUSES AND SCHEDULES ARE TO CLAUSES AND SCHEDULES TO
          THIS SHARE CHARGE,

     (B)  HEADINGS TO CLAUSES ARE FOR CONVENIENCE ONLY AND ARE TO BE IGNORED IN
          CONSTRUING THIS SHARE CHARGE,

     (C)  REFERENCES TO A "PERSON" ARE TO BE CONSTRUED SO AS TO INCLUDE ANY
          INDIVIDUAL, FIRM, COMPANY, GOVERNMENT, STATE OR AGENCY OF A STATE,
          LOCAL OR MUNICIPAL AUTHORITY, OR ANY JOINT VENTURE, ASSOCIATION OR
          PARTNERSHIP (WHETHER OR NOT HAVING SEPARATE LEGAL PERSONALITY);

     (D)  REFERENCES TO A "COMPANY" ARE TO BE CONSTRUED SO AS TO INCLUDE ANY
          COMPANY, CORPORATION OR OTHER BODY CORPORATE, WHEREVER AND HOWEVER
          INCORPORATED OR ESTABLISHED;

     (E)  REFERENCES TO ANY STATUTE OR STATUTORY PROVISION ARE TO BE CONSTRUED
          AS REFERENCES TO THE SAME AS IT MAY HAVE BEEN, OR MAY FROM TIME TO
          TIME BE, AMENDED, MODIFIED OR RE-ENACTED, AND INCLUDE REFERENCES TO
          ALL BYE-LAWS, INSTRUMENTS, ORDERS AND REGULATIONS FOR THE TIME BEING
          MADE THEREUNDER OR DERIVING VALIDITY THEREFROM;

     (F)  ANY REFERENCE TO A "DAY" (INCLUDING WITHIN THE PHRASE BUSINESS DAY)
          SHALL MEAN A PERIOD OF 24 HOURS RUNNING FROM MIDNIGHT TO MIDNIGHT;

     (G)  REFERENCES TO TIME ARE TO LONDON TIME;

                                       4
<PAGE>

     (H)  ANY REFERENCE IN THIS SHARE CHARGE TO "THIS SHARE CHARGE", THE
          SECURITIES PURCHASE AGREEMENT, THE NOTES, THE COLLATERAL AGENCY
          AGREEMENT OR ANY OTHER DEED, AGREEMENT OR INSTRUMENT IS A REFERENCE TO
          THIS SHARE CHARGE OR, AS THE CASE MAY BE, THE RELEVANT DEED, AGREEMENT
          OR INSTRUMENT AS AMENDED, SUPPLEMENTED, REPLACED OR NOVATED FROM TIME
          TO TIME AND INCLUDES A REFERENCE TO ANY DOCUMENT WHICH AMENDS,
          SUPPLEMENTS, REPLACES, NOVATES OR IS ENTERED INTO, MADE OR GIVEN
          PURSUANT TO OR IN ACCORDANCE WITH ANY OF THE TERMS OF THIS SHARE
          CHARGE OR, AS THE CASE MAY BE, THE RELEVANT DEED, AGREEMENT OR
          INSTRUMENT;

     (I)  A REFERENCE IN THIS SHARE CHARGE TO ANY "ASSETS" INCLUDES PRESENT AND
          FUTURE PROPERTIES, REVENUES AND RIGHTS OF EVERY DESCRIPTION; AND

     (J)  THE SECURITY AGENT HOLDS THE SECURITY CONSTITUTED BY THIS DEED ON
          TRUST FOR THE SECURED PARTIES IN ACCORDANCE WITH THE PROVISIONS OF THE
          COLLATERAL AGENCY AGREEMENT; AND

     (K)  SECTION 1 OF THE TRUSTEE ACT 2000 SHALL NOT APPLY TO THE DUTIES OF THE
          SECURITY AGENT IN RELATION TO THE TRUSTS CONSTITUTED BY THIS SHARE
          CHARGE. WHERE THERE ARE ANY INCONSISTENCIES BETWEEN THAT ACT AND THE
          PROVISIONS OF THIS SHARE CHARGE, THE PROVISIONS OF THIS SHARE CHARGE
          SHALL, TO THE EXTENT ALLOWED BY LAW, PREVAIL AND IN THE CASE OF ANY
          INCONSISTENCY WITH THAT ACT, THE PROVISIONS OF THIS SHARE CHARGE SHALL
          CONSTITUTE A RESTRICTION OR EXCLUSION FOR THE PURPOSES OF THAT ACT.

2.   CLAWBACK

     (A)  IF THE SECURITY AGENT CONSIDERS THAT ANY AMOUNT PAID OR CREDITED TO IT
          IS CAPABLE OF BEING AVOIDED OR REDUCED BY VIRTUE OF ANY BANKRUPTCY,
          INSOLVENCY, LIQUIDATION OR SIMILAR LAWS THE LIABILITY OF THE CHARGOR
          UNDER THIS SHARE CHARGE AND THE SECURITY CONSTITUTED HEREBY WILL
          CONTINUE AND SUCH AMOUNT WILL NOT BE CONSIDERED TO HAVE BEEN
          IRREVOCABLY PAID.

     (B)  WHERE ANY DISCHARGE (WHETHER IN RESPECT OF THE OBLIGATIONS OF THE
          CHARGOR, THE BORROWER OR ANY SECURITY FOR THOSE OBLIGATIONS OR
          OTHERWISE) IS MADE IN WHOLE OR IN PART OR ANY ARRANGEMENT IS MADE ON
          THE FAITH OF ANY PAYMENT, SECURITY OR OTHER DISPOSITION WHICH IS
          AVOIDED OR MUST BE RESTORED ON INSOLVENCY, LIQUIDATION OR OTHERWISE,
          THE LIABILITY OF THE CHARGOR UNDER THIS SHARE CHARGE SHALL CONTINUE AS
          IF THE DISCHARGE OR THE ARRANGEMENTS HAD NOT OCCURRED.

     (C)  THE SECURITY AGENT MAY CONCEDE OR COMPROMISE ANY CLAIM THAT ANY
          PAYMENT, SECURITY OR OTHER DISPOSITION IS LIABLE TO AVOIDANCE OR
          RESTORATION.

                                       5
<PAGE>

3.   FIXED CHARGE

     (A)  THE CHARGOR HEREBY CHARGES WITH FULL TITLE GUARANTEE THE COLLATERAL TO
          THE SECURITY AGENT (FOR THE BENEFIT OF ITSELF AND THE OTHER SECURED
          PARTIES) BY WAY OF FIRST FIXED CHARGE AND AS A CONTINUING SECURITY FOR
          THE PAYMENT AND DISCHARGE OF THE SECURED OBLIGATIONS.

     (B)  THE CHARGOR WILL DEPOSIT WITH THE SECURITY AGENT DURING THE SECURITY
          PERIOD ALL DEEDS, CERTIFICATES AND/OR DOCUMENTS OF TITLE OR OTHER
          EVIDENCE OF OWNERSHIP OF THE COLLATERAL, AND DECLARATIONS OF TRUST IN
          FAVOUR OF THE CHARGOR EXECUTED BY ALL PERSONS (OTHER THAN THE
          CHARGOR), TOGETHER WITH BLANK, EXECUTED STOCK TRANSFER FORMS AND ANY
          OTHER DOCUMENTS AS ARE NECESSARY FOR THE SECURITY AGENT TO REGISTER
          ITS INTEREST, OR THAT OF ITS NOMINEE, IN THE COLLATERAL. THE SECURITY
          AGENT MAY, UPON THIS SHARE CHARGE BECOMING ENFORCEABLE AND UPON GIVING
          NOTICE TO THE CHARGOR, COMPLETE SUCH TRANSFERS AND PRESENT THEM FOR
          REGISTRATION.

4.   REPRESENTATIONS AND WARRANTIES

     THE CHARGOR REPRESENTS AND WARRANTS THAT TO THE SECURITY AGENT THAT:

     (I)  IT IS DULY INCORPORATED AND VALIDLY EXISTING UNDER THE LAWS OF ENGLAND
          AND WALES AND IS FULLY QUALIFIED AND EMPOWERED TO OWN ITS ASSETS AND
          CARRY OUT ITS BUSINESSES;

     (II) IT HAS POWER TO ENTER INTO THIS SHARE CHARGE AND TO PERFORM ITS
          OBLIGATIONS HEREUNDER AND HAS TAKEN ALL NECESSARY CORPORATE AND OTHER
          ACTION TO AUTHORISE THE EXECUTION, DELIVERY AND PERFORMANCE OF THIS
          SHARE CHARGE;

     (III)THE OBLIGATIONS EXPRESSED TO BE ASSUMED BY IT IN THIS SHARE CHARGE ARE
          LEGAL AND VALID OBLIGATIONS BINDING ON IT IN ACCORDANCE WITH THE TERMS
          OF THIS SHARE CHARGE SUBJECT TO GENERAL PRINCIPLES OF LAW AFFECTING
          CREDITORS' RIGHTS;

     (IV) IT HAS NOT TAKEN ANY CORPORATE ACTION NOR HAVE ANY OTHER STEPS BEEN
          TAKEN OR LEGAL PROCEEDINGS BEEN STARTED OR THREATENED AGAINST IT FOR
          ITS WINDING UP, DISSOLUTION OR REORGANISATION OR FOR THE APPOINTMENT
          OF A RECEIVER, ADMINISTRATOR, ADMINISTRATIVE RECEIVER, TRUSTEE OR
          SIMILAR OFFICER OF IT OR OF ANY OR ALL OF ITS REVENUES OR ASSETS;

     (v)  THIS SHARE CHARGE CREATES THE SECURITY THAT IT PURPORTS TO CREATE;

     (VI) IT IS AND WILL BE THE REGISTERED AND BENEFICIAL OWNER OF THE
          COLLATERAL, FREE AND CLEAR OF ANY SECURITY AND THE SHARES ARE AND WILL
          BE FULLY PAID UP; AND

                                       6
<PAGE>

     (VII)THERE ARE NO RESTRICTIONS ON THE VOTING RIGHTS ASSOCIATED WITH, OR
          UPON THE TRANSFER TO OR BY THE SECURITY AGENT OF, ANY OF THE
          COLLATERAL.

5.   VOTING RIGHTS

     (A)  UNLESS AND UNTIL THE OCCURRENCE OF AN EVENT OF DEFAULT, THE CHARGOR
          SHALL HAVE THE RIGHT TO VOTE ON THE SHARES FOR ANY PURPOSE IN A MANNER
          NOT INCONSISTENT WITH THE TERMS OF THIS SHARE CHARGE AND ANY OTHER
          AGREEMENT, INSTRUMENT OR DOCUMENT EXECUTED PURSUANT THERETO OR IN
          CONNECTION THEREWITH.

     (B)  AT ANY TIME ON OR AFTER THE OCCURRENCE OF AN EVENT OF DEFAULT:

          (i)  THE SECURITY AGENT OR ITS NOMINEE MAY (IN THE NAME OF THE CHARGOR
               OR OTHERWISE AND WITHOUT ANY FURTHER CONSENT OR AUTHORITY ON THE
               PART OF THE CHARGOR) EXERCISE ALL VOTING POWERS AND OTHER RIGHTS
               PERTAINING TO THE COLLATERAL (INCLUDING THE RIGHT TO NOMINATE OR
               REMOVE A DIRECTOR) AS IF THE SECURITY AGENT WAS THE SOLE
               BENEFICIAL OWNER OF THE COLLATERAL; AND

          (II) THE CHARGOR SHALL (AND SHALL PROCURE THAT ITS NOMINEES SHALL)
               ACCEPT SHORT NOTICE FOR AND ATTEND ANY MEETING OF THE HOLDERS OF
               ANY COLLATERAL, APPOINT PROXIES AND EXERCISE VOTING AND OTHER
               RIGHTS AND POWERS EXERCISABLE BY THE HOLDER OF THE COLLATERAL AS
               THE SECURITY AGENT MAY DIRECT FROM TIME TO TIME.

6.   DIVIDENDS AND OTHER DISTRIBUTIONS

(A)  UNLESS AND UNTIL THE OCCURRENCE OF AN EVENT OF DEFAULT, THE CHARGOR SHALL
     BE ENTITLED TO RECEIVE AND RETAIN ANY AND ALL DIVIDENDS AND INTEREST PAID
     IN RESPECT OF THE COLLATERAL.

(B)  AT ANY TIME ON OR AFTER THE OCCURRENCE OF AN EVENT OF DEFAULT:

     (i)  ALL RIGHTS OF THE CHARGOR TO RECEIVE THE DIVIDENDS AND INTEREST
          PAYMENTS WHICH IT WOULD OTHERWISE BE AUTHORISED TO RECEIVE AND RETAIN
          PURSUANT TO PARAGRAPH (A) ABOVE SHALL CEASE, AND ALL SUCH RIGHTS SHALL
          THEREUPON BECOME VESTED IN THE SECURITY AGENT; AND

     (II) ALL DIVIDENDS AND INTEREST PAYMENTS WHICH ARE RECEIVED BY THE CHARGOR
          CONTRARY TO THE PROVISIONS OF SUB-PARAGRAPH (i) OF THIS PARAGRAPH (B)
          SHALL BE RECEIVED IN TRUST FOR THE SECURITY AGENT, SHALL BE SEGREGATED
          FROM OTHER FUNDS OF THE CHARGOR AND SHALL BE PAID OVER IMMEDIATELY TO
          THE SECURITY AGENT.

7.   COVENANTS

                                       7
<PAGE>

THE CHARGOR COVENANTS WITH THE SECURITY AGENT THAT IT SHALL:

(A)  NOT SELL, TRANSFER, ASSIGN OR OTHERWISE DISPOSE OF (OTHER THAN TO THE
     SECURITY AGENT OR A NOMINEE OF THE SECURITY AGENT) THE COLLATERAL OR ANY
     INTEREST IN ANY OF THE COLLATERAL, NOR ATTEMPT OR AGREE TO DO SO;

(B)  NOT CREATE OR AGREE TO CREATE OR PERMIT TO ARISE ANY SECURITY OVER THE
     COLLATERAL (SAVE FOR THE SECURITY CREATED BY THIS SHARE CHARGE);

(C)  NOT DO OR CAUSE OR PERMIT TO BE DONE ANYTHING WHICH MAY IN ANY WAY
     DEPRECIATE, JEOPARDISE OR OTHERWISE PREJUDICE THE VALUE OF THE COLLATERAL;

(D)  NOTIFY THE SECURITY AGENT OF THE CONTENTS OF ANY COMMUNICATION OR DOCUMENT
     WHICH IT RECEIVES AS HOLDER OF ANY OF THE SHARES;

(E)  ENSURE THAT THE SHARES ARE AT ALL TIMES FREE FROM ANY RESTRICTION ON
     TRANSFER TO OR BY THE SECURITY AGENT TO PERFECT ITS SECURITY;

(F)  NOT, BY THE EXERCISE OF ANY VOTING RIGHTS OR OTHERWISE, PERMIT OR AGREE
     (WITHOUT THE PRIOR WRITTEN CONSENT OF THE SECURITY AGENT) TO ANY PROPOSED
     COMPROMISE, ARRANGEMENT, CAPITAL REORGANISATION, CONVERSION, EXCHANGE,
     REPAYMENT OR TAKEOVER OFFER AFFECTING OR IN RESPECT OF ANY OF THE SHARES;

(G)  DULY AND PROMPTLY PAY ALL CALLS, INSTALMENTS AND OTHER PAYMENTS IN RESPECT
     OF THE COLLATERAL (AND IF THE CHARGOR DEFAULTS IN MAKING ANY SUCH PAYMENT,
     THE SECURITY AGENT MAY PAY SUCH AMOUNTS ON HIS BEHALF AND SHALL BE
     REIMBURSED BY THE CHARGOR).

8.   POWERS OF THE SECURITY TRUSTEE

(A)  IF THE CHARGOR FAILS TO COMPLY WITH ANY OBLIGATION, COVENANT OR STIPULATION
     AFFECTING THE COLLATERAL (WHETHER SET OUT IN THIS SHARE CHARGE OR
     OTHERWISE), THE CHARGOR WILL PERMIT THE SECURITY AGENT OR ITS OFFICERS,
     EMPLOYEES, AGENTS OR DELEGATES TO TAKE POSSESSION OF SUCH COLLATERAL AND DO
     ALL SUCH THINGS AS THE SECURITY AGENT MAY REASONABLY CONSIDER NECESSARY OR
     DESIRABLE TO PREVENT OR REMEDY ANY BREACH OF SUCH OBLIGATION, COVENANT OR
     STIPULATION.

(B)  THE CHARGOR WILL INDEMNIFY THE SECURITY AGENT AGAINST ALL LOSSES,
     LIABILITIES, COSTS AND EXPENSES PROPERLY INCURRED IN CONNECTION WITH THE
     EXERCISE OF THE POWERS CONTAINED IN PARAGRAPH (A) ABOVE.

                                       8
<PAGE>

9.   PROVISIONS AS TO SECURITY

9.1  FURTHER ASSURANCE

     THE CHARGOR SHALL PROMPTLY DO ALL SUCH ACTS OR EXECUTE ALL SUCH DOCUMENTS
     (INCLUDING ASSIGNMENTS, TRANSFERS, MORTGAGES, CHARGES, NOTICES AND
     INSTRUCTIONS) AS THE SECURITY AGENT MAY REASONABLY SPECIFY (AND IN SUCH
     FORM AS THE SECURITY AGENT MAY REASONABLY REQUIRE IN FAVOUR OF THE SECURITY
     AGENT OR ITS NOMINEE(s)) TO:

          (1)  PERFECT THE SECURITY CREATED OR INTENDED TO BE CREATED IN RESPECT
               OF THE COLLATERAL OR FOR THE EXERCISE OF THE RIGHTS, POWERS AND
               REMEDIES OF THE SECURITY AGENT PROVIDED BY OR PURSUANT TO THIS
               SHARE CHARGE OR BY LAW; AND/OR

          (2)  FACILITATE THE REALISATION OF THE COLLATERAL.

9.2  CONTINUING SECURITY

(A)  THE SECURITY FROM TIME TO TIME CONSTITUTED BY THIS SHARE CHARGE IS A
     CONTINUING SECURITY AND WILL REMAIN IN FULL FORCE AND EFFECT AS A
     CONTINUING SECURITY UNTIL RELEASED OR DISCHARGED BY THE SECURITY AGENT.

(B)  NO PART OF THE SECURITY FROM TIME TO TIME CONSTITUTED BY THIS SHARE CHARGE
     WILL BE CONSIDERED SATISFIED OR DISCHARGED BY ANY INTERMEDIATE PAYMENT,
     DISCHARGE OR SATISFACTION OF THE WHOLE OR ANY PART OF THE SECURED
     OBLIGATIONS.

9.3  NON-MERGER

     EACH PART OF THE SECURITY FROM TIME TO TIME INTENDED TO BE CONSTITUTED
     UNDER THIS SHARE CHARGE WILL BE CUMULATIVE, IN ADDITION TO AND WILL NOT
     OPERATE SO AS IN ANY WAY TO LIMIT OR AFFECT (OR BE LIMITED OR AFFECTED BY)
     ANY OTHER RIGHT, REMEDY, SECURITY OR GUARANTEE HELD BY THE SECURITY AGENT
     AND/OR ANY OF THE OTHER SECURED PARTIES FOR THE SECURED OBLIGATIONS.

9.4  NO PREJUDICE

     THE SECURITY CREATED BY OR PURSUANT TO THIS SHARE CHARGE AND THE RIGHTS,
     POWERS AND REMEDIES OF THE SECURITY AGENT PROVIDED BY OR PURSUANT TO THIS
     SHARE CHARGE OR BY LAW SHALL NOT BE PREJUDICED BY ANY UNENFORCEABILITY OR
     INVALIDITY OF ANY OTHER AGREEMENT OR DOCUMENT OR BY ANY TIME OR INDULGENCE
     GRANTED TO THE CHARGOR OR ANY OTHER PERSON, OR THE SECURITY AGENT (WHETHER
     IN ITS CAPACITY AS TRUSTEE OR OTHERWISE) OR BY ANY VARIATION OF THE TERMS
     OF THE TRUST UPON WHICH THE SECURITY AGENT HOLDS THE

                                       9
<PAGE>

     SECURITY OR BY ANY OTHER THING WHICH MIGHT OTHERWISE PREJUDICE THAT
     SECURITY OR ANY RIGHTS, POWERS AND REMEDIES OF THE SECURITY AGENT PROVIDED
     BY OR PURSUANT TO THIS SHARE CHARGE OR BY LAW.

9.5  ADDITIONAL SECURITY

     THIS SHARE CHARGE IS IN ADDITION TO, AND SHALL NOT PREJUDICE OR AFFECT ANY
     OTHER SECURITY OR OTHER RIGHT OR REMEDY NOW OR SUBSEQUENTLY HELD BY OR IN
     FAVOUR OF THE SECURITY AGENT AND/OR ANY SECURED PARTY.

9.6  SECURITY HELD BY THE CHARGOR

     THE CHARGOR WILL NOT, WITHOUT THE PRIOR WRITTEN CONSENT OF THE SECURITY
     AGENT, HOLD ANY SECURITY FROM ANY OTHER PERSON IN RESPECT OF ITS LIABILITY
     UNDER THE TRANSACTION DOCUMENTS. THE CHARGOR WILL HOLD ANY SECURITY HELD BY
     IT IN BREACH OF THIS PROVISION ON TRUST FOR THE SECURITY AGENT.

10.  ENFORCEABILITY

     ANY TIME AFTER THE OCCURRENCE OF AN EVENT OF DEFAULT OR IF THE CHARGOR
     REQUESTS THE SECURITY AGENT TO EXERCISE ANY OF ITS POWERS UNDER THIS SHARE
     CHARGE, THE SECURITY CREATED BY OR PURSUANT TO THIS SHARE CHARGE IS
     IMMEDIATELY ENFORCEABLE AND THE SECURITY AGENT MAY, WITHOUT NOTICE TO THE
     CHARGOR OR PRIOR AUTHORISATION FROM ANY COURT, IN ITS ABSOLUTE DISCRETION,
     ENFORCE ALL OR ANY PART OF THE SECURITY AT THE TIMES, IN THE MANNER AND ON
     THE TERMS IT THINKS FIT.

11.  ENFORCEMENT OF SECURITY

11.1. POWER OF SALE

     (A)  THE POWER OF SALE OR OTHER DISPOSAL CONFERRED ON THE SECURITY AGENT BY
          SECTION 101 OF THE LAW & PROPERTY ACT 1925, AS VARIED OR AMENDED BY
          THIS SHARE CHARGE SHALL ARISE (AND THE SECURED OBLIGATIONS SHALL BE
          DEEMED DUE AND PAYABLE FOR THAT PURPOSE) AND SHALL BE IMMEDIATELY
          EXERCISABLE ON THE OCCURRENCE OF AN EVENT OF DEFAULT.

     (B)  THE RESTRICTIONS CONTAINED IN SECTIONS 93 AND 103 OF THE LAW OF
          PROPERTY ACT 1925 SHALL NOT APPLY TO THIS SHARE CHARGE OR TO THE
          EXERCISE BY THE SECURITY AGENT OF ITS RIGHT TO CONSOLIDATE ALL OR ANY
          OF THE SECURITY CREATED BY OR PURSUANT TO THIS SHARE CHARGE WITH ANY
          OTHER SECURITY IN EXISTENCE AT ANY TIME OR TO ITS POWER OF SALE, WHICH
          POWERS MAY BE EXERCISED BY THE SECURITY AGENT WITHOUT NOTICE TO THE
          CHARGOR ON OR AT ANY TIME AFTER THE OCCURRENCE OF AN EVENT OF DEFAULT.

11.2 MORTGAGEE'S LIABILITY

                                       10
<PAGE>

     THE SECURITY AGENT WILL NOT BE LIABLE TO ACCOUNT AS MORTGAGEE OR MORTGAGEE
     IN POSSESSION IN RESPECT OF THE COLLATERAL OR BE LIABLE FOR ANY LOSS UPON
     REALISATION OR FOR ANY NEGLECT OR DEFAULT OF ANY NATURE WHATSOEVER IN
     CONNECTION WITH THE COLLATERAL FOR WHICH A MORTGAGEE OR MORTGAGEE IN
     POSSESSION MIGHT AS SUCH BE LIABLE, SAVE WHERE CAUSED BY THE GROSS
     NEGLIGENCE OR WILFUL DEFAULT OF THE SECURITY AGENT, IN WHICH CASE THE
     LIABILITY OF THE SECURITY AGENT WILL BE LIMITED TO THE ACTUAL LOSS SUFFERED
     AS A DIRECT RESULT OF SUCH GROSS NEGLIGENCE OR WILFUL DEFAULT.

11.3 DELEGATION

     (A)  THE SECURITY AGENT MAY FROM TIME TO TIME DELEGATE BY POWER OF ATTORNEY
          OR OTHERWISE TO ANY PERSON OR CORPORATION ANY OF THE POWERS AND
          DISCRETIONS OF THE SECURITY AGENT UNDER THIS SHARE CHARGE WHETHER
          ARISING BY STATUTE, THE PROVISIONS HEREOF OR OTHERWISE UPON SUCH TERMS
          AND FOR SUCH PERIODS OF TIME AS IT MAY THINK FIT AND MAY DETERMINE ANY
          SUCH DELEGATION.

     (B)  THE SECURITY AGENT WILL NOT BE LIABLE TO THE CHARGOR FOR ANY LOSS OR
          DAMAGE ARISING FROM ANY ACT, DEFAULT, OMISSION OR MISCONDUCT OF ANY
          SUCH DELEGATE AND REFERENCES IN THIS SHARE CHARGE TO THE SECURITY
          AGENT WILL WHERE THE CONTEXT SO ADMITS INCLUDE REFERENCES TO ANY
          DELEGATES SO APPOINTED.

12.  APPLICATION OF PROCEEDS

     ALL MONEYS RECEIVED OR RECOVERED BY THE SECURITY AGENT PURSUANT TO THIS
     SHARE CHARGE OR THE POWERS CONFERRED BY IT SHALL (SAVE AS PROVIDED IN AND
     SUBJECT TO THE PROVISIONS OF THE TRANSACTION DOCUMENTS AND SUBJECT TO THE
     CLAIMS OF ANY PERSON HAVING PRIOR RIGHTS THERETO) BE APPLIED:

     (A)  FIRST IN THE PAYMENT OF THE COSTS, CHARGES AND EXPENSES INCURRED AND
          PAYMENTS MADE BY THE SECURITY AGENT UNDER OR IN CONNECTION WITH THIS
          SHARE CHARGE AND/OR THE EXERCISE BY THE SECURITY AGENT OF ANY OF ITS
          RIGHTS HEREUNDER;

     (B)  SECOND IN OR TOWARDS THE PAYMENT OR DISCHARGE OF SUCH OF THE SECURED
          OBLIGATIONS IN SUCH ORDER AS THE SECURITY AGENT IN ITS ABSOLUTE
          DISCRETION MAY FROM TIME TO TIME DETERMINE; AND

     (C)  THIRD, AFTER ALL THE SECURED OBLIGATIONS HAVE BEEN PAID OR DISCHARGED
          IN FULL, IN PAYMENT OF ANY SURPLUS TO THE CHARGOR OR OTHER PERSON
          ENTITLED TO IT.

13.  POWER OF ATTORNEY

13.1 APPOINTMENT AND POWERS

                                       11
<PAGE>

     THE CHARGOR BY WAY OF SECURITY IRREVOCABLY APPOINTS THE SECURITY AGENT
     SEVERALLY TO BE ITS ATTORNEY AND IN ITS NAME, ON ITS BEHALF AND AS ITS ACT
     AND DEED TO EXECUTE, DELIVER AND PERFECT ALL DOCUMENTS AND DO ALL THINGS
     WHICH THE ATTORNEY MAY CONSIDER TO BE REQUIRED OR DESIRABLE FOR:

     (A)  CARRYING OUT ANY OBLIGATION IMPOSED ON THE CHARGOR BY THIS SHARE
          CHARGE (INCLUDING THE EXECUTION AND DELIVERY OF ANY DEEDS, CHARGES,
          ASSIGNMENTS OR OTHER SECURITY AND ANY TRANSFERS OF THE COLLATERAL);
          AND

     (B)  ENABLING THE SECURITY AGENT TO EXERCISE, OR DELEGATE THE EXERCISE OF,
          ANY OF THE RIGHTS, POWERS AND AUTHORITIES CONFERRED ON THEM BY OR
          PURSUANT TO THIS SHARE CHARGE OR BY LAW (INCLUDING, AFTER THE
          OCCURRENCE OF AN EVENT OF DEFAULT, THE EXERCISE OF ANY RIGHT OF A
          LEGAL OR BENEFICIAL OWNER OF THE COLLATERAL).

13.2 RATIFICATION

     THE CHARGOR SHALL RATIFY AND CONFIRM ALL THINGS DONE AND ALL DOCUMENTS
     EXECUTED BY ANY ATTORNEY IN THE EXERCISE OR PURPORTED EXERCISE OF ALL OR
     ANY OF HIS POWERS.

14.  NEW ACCOUNTS

14.1 SUBSEQUENT SECURITY

     IF THE SECURITY AGENT AT ANY TIME RECEIVES NOTICE OF ANY SUBSEQUENT
     SECURITY OR OTHER LIKE INTEREST, MATTER, EVENT OR TRANSACTION AFFECTING ANY
     PART OF IT, THE SECURITY AGENT MAY OPEN A NEW ACCOUNT OR ACCOUNTS FOR THE
     CHARGOR IN ITS BOOKS.

14.2 PRESUMPTION

     IF THE SECURITY AGENT DOES NOT OPEN ANY SUCH NEW ACCOUNT THEN, UNLESS IT
     GIVES EXPRESS WRITTEN NOTICE TO THE CHARGOR TO THE CONTRARY, THE SECURITY
     AGENT WILL BE TREATED AS IF IT HAD IN FACT OPENED SUCH ACCOUNT OR ACCOUNTS
     AT THE TIME WHEN IT RECEIVED SUCH NOTICE AND AS FROM THAT TIME AND UNLESS
     SUCH EXPRESS WRITTEN NOTICE IS GIVEN TO THE CHARGOR ALL PAYMENTS BY OR ON
     BEHALF OF THE CHARGOR TO THE SECURITY AGENT WILL (IN THE ABSENCE OF ANY
     EXPRESS CONTRARY APPROPRIATION BY THE CHARGOR) BE CREDITED OR TREATED AS
     HAVING BEEN CREDITED TO A NEW ACCOUNT OF THE CHARGOR AND NOT AS HAVING BEEN

                                       12
<PAGE>

     APPLIED IN REDUCTION OF THE CHARGER'S INDEBTEDNESS AND OTHER LIABILITIES TO
     THE SECURITY AGENT AT THE TIME WHEN SUCH NOTICE WAS RECEIVED.

15.  SUSPENSE ACCOUNTS

15.1 MONEYS RECEIVED

     ALL MONEYS RECEIVED, RECOVERED OR REALISED BY THE SECURITY AGENT UNDER THIS
     SHARE CHARGE (INCLUDING THE PROCEEDS OF ANY CONVERSION OF CURRENCY) MAY IN
     THE DISCRETION OF THE SECURITY AGENT BE CREDITED TO ANY INTEREST BEARING
     SUSPENSE OR IMPERSONAL ACCOUNT MAINTAINED WITH ANY BANK, BUILDING SOCIETY
     OR FINANCIAL INSTITUTION AS IT CONSIDERS APPROPRIATE AND MAY BE HELD IN
     SUCH ACCOUNT FOR SO LONG AS THE SECURITY AGENT MAY THINK FIT PENDING THEIR
     APPLICATION FROM TIME TO TIME (AS THE SECURITY AGENT IS ENTITLED TO DO IN
     ITS DISCRETION) IN OR TOWARDS THE DISCHARGE OF ANY OF THE SECURED
     OBLIGATIONS AND SAVE AS PROVIDED HEREIN NO PARTY WILL BE ENTITLED TO
     WITHDRAW ANY AMOUNT AT ANY TIME STANDING TO THE CREDIT OF ANY SUSPENSE OR
     IMPERSONAL ACCOUNT REFERRED TO ABOVE, PROVIDED ALWAYS THAT:

     (A)  ANY AMOUNTS STANDING TO THE CREDIT OF ANY SUCH SUSPENSE OR IMPERSONAL
          ACCOUNT SHALL BEAR INTEREST AT THE MARKET RATE PAYABLE FROM TIME TO
          TIME BY THE SECURITY AGENT FOR DEPOSITS OF A SIMILAR AMOUNT AND
          MATURITY; AND

     (B)  THE SECURITY AGENT SHALL APPLY ALL SUCH MONEYS STANDING TO THE CREDIT
          OF SUCH SUSPENSE OR IMPERSONAL ACCOUNT IN PAYMENT AND DISCHARGE OF THE
          SECURED OBLIGATIONS AS SOON AS THE AMOUNT STANDING TO THE CREDIT OF
          SUCH SUSPENSE OR IMPERSONAL ACCOUNT IS SUFFICIENT TO DISCHARGE IN FULL
          EACH AND ALL OF THE SECURED OBLIGATIONS.

15.2 APPLICATION

     WITHOUT PREJUDICE TO ITS RIGHTS UNDER THIS SHARE CHARGE OR AT LAW, THE
     SECURITY AGENT SHALL APPLY ALL MONIES REFERRED TO IN CLAUSE 15.1 (MONEYS
     RECEIVED) AS SOON AS REASONABLY PRACTICABLE IN ACCORDANCE WITH CLAUSE 12
     (APPLICATION OF PROCEEDS).

16.  SET OFF

     (A)  THE CHARGOR AUTHORISES THE SECURITY AGENT, AT ANY TIME ON OR AFTER THE
          DATE THIS SHARE CHARGE BECOMES ENFORCEABLE IN ACCORDANCE WITH CLAUSE
          10 (ENFORCEABILITY) AND WITHOUT PRIOR NOTICE TO THE CHARGOR, TO APPLY
          ANY CREDIT BALANCE (WHETHER OR NOT THEN DUE) TO WHICH

                                       13
<PAGE>

          THE CHARGOR IS AT ANY TIME BENEFICIALLY ENTITLED ON ANY ACCOUNT AT ANY
          OFFICE OF THE SECURITY AGENT IN OR TOWARDS SATISFACTION OF THE SECURED
          OBLIGATIONS.

     (B)  THE SECURITY AGENT MAY MAKE SUCH APPLICATION NOTWITHSTANDING ANY
          SPECIFIED MATURITY OF ANY DEPOSITS STANDING TO THE CREDIT OF ANY
          ACCOUNT OF THE CHARGOR WITH THE SECURITY AGENT.

     (C)  FOR THE PURPOSES OF PARAGRAPH (A) ABOVE THE SECURITY AGENT IS
          AUTHORISED TO PURCHASE WITH THE MONEYS STANDING TO THE CREDIT OF ANY
          SUCH ACCOUNT SUCH OTHER CURRENCIES AS MAY BE NECESSARY TO EFFECT SUCH
          APPLICATION.

     (D)  THE SECURITY AGENT SHALL NOT BE OBLIGED TO EXERCISE ANY OF ITS RIGHTS
          UNDER THIS CLAUSE 16 (SET- OFF) WHICH SHALL BE WITHOUT PREJUDICE TO
          AND IN ADDITION TO ANY RIGHTS OF SET-OFF, COMBINATION OF ACCOUNTS,
          CONSOLIDATION OR OTHER RIGHTS TO WHICH IT IS AT ANY TIME OTHERWISE
          ENTITLED (WHETHER BY OPERATION OF LAW, CONTRACT OR OTHERWISE).

17.  TRANSFERS

     THE CHARGOR MAY NOT ASSIGN OR OTHERWISE TRANSFER ITS RIGHTS AND OBLIGATIONS
     UNDER THIS SHARE CHARGE.

18.  RELEASE OF SECURITY

     UPON THE EARLIER TO OCCUR OF (i) EXPIRY OF THE SECURITY PERIOD, AND (II)
     THE DATE ON WHICH A QUALIFIED IPO (AS DEFINED IN THE NOTES) IS CONSUMMATED
     (OR AT A TIME OTHERWISE APPROVED BY THE SECURITY AGENT IN ACCORDANCE WITH,
     SAVE AS PROVIDED IN, AND SUBJECT TO THE PROVISIONS OF THE TRANSACTION
     DOCUMENTS), THE SECURITY AGENT WILL, AT THE REQUEST AND COST OF THE
     CHARGOR, RELEASE, REASSIGN OR DISCHARGE (AS APPROPRIATE) THE COLLATERAL
     FROM THE SECURITY CREATED BY THIS SHARE CHARGE WITHOUT RECOURSE OR
     WARRANTY.

19.  MISCELLANEOUS

19.1 WAIVER OF DEFENCES

     THE OBLIGATIONS OF THE CHARGOR UNDER THIS SHARE CHARGE AND THIS SECURITY
     WILL NOT BE AFFECTED BY ANY ACT, OMISSION, MATTER OR THING WHICH, BUT FOR
     THIS CLAUSE 19.1 (WAIVER OF DEFENCES), WOULD REDUCE RELEASE OR PREJUDICE
     ANY OF ITS OBLIGATIONS UNDER THIS SHARE CHARGE AND THIS SECURITY AND
     WHETHER OR NOT KNOWN TO THE CHARGOR OR THE SECURITY AGENT INCLUDING:

     (A)  ANY TIME, WAIVER, INDULGENCE OR CONSENT GRANTED TO, OR COMPOSITION
          WITH, THE BORROWER OR OTHER PERSON;

                                       14
<PAGE>

     (B)  THE RELEASE OF THE CHARGOR OR ANY OTHER PERSON UNDER THE TERMS OF ANY
          COMPOSITION OR ARRANGEMENT WITH ANY CREDITOR OF ANY MEMBER OF THE
          GROUP OF COMPANIES TO WHICH THE CHARGOR BELONGS;

     (C)  THE TAKING, VARIATION, COMPROMISE, EXCHANGE, RENEWAL OR RELEASE OF, OR
          REFUSAL OR NEGLECT TO PERFECT, TAKE UP OR ENFORCE, ANY RIGHTS AGAINST,
          OR SECURITY OVER ASSETS OF, THE BORROWER OR OTHER PERSON OR ANY
          NON-PRESENTMENT OR NON-OBSERVANCE OF ANY FORMALITY OR OTHER
          REQUIREMENT IN RESPECT OF ANY INSTRUMENTS OR ANY FAILURE TO REALISE
          THE FULL VALUE OF ANY SECURITY;

     (D)  ANY INCAPACITY OR LACK OF POWERS, AUTHORITY OR LEGAL PERSONALITY OF OR
          DISSOLUTION OR CHANGE IN THE MEMBERS OR STATUS OF, THE BORROWER OR ANY
          OTHER PERSON;

     (E)  ANY AMENDMENT (HOWEVER FUNDAMENTAL) OR REPLACEMENT OF ANY DOCUMENT OR
          SECURITY;

     (F)  ANY UNENFORCEABILITY, ILLEGALITY OR INVALIDITY OF ANY OBLIGATION OF
          ANY PERSON UNDER ANY DOCUMENT OR SECURITY; AND

     (G)  ANY INSOLVENCY OR SIMILAR PROCEEDINGS.

19.2 IMMEDIATE RECOURSE

     THE CHARGOR WAIVES ANY RIGHT IT MAY HAVE OF FIRST REQUIRING THE SECURITY
     AGENT (OR ANY TRUSTEE OR AGENT ON ITS BEHALF) TO PROCEED AGAINST OR ENFORCE
     ANY OTHER RIGHTS OR SECURITY OR CLAIM PAYMENT FROM ANY OTHER PERSON BEFORE
     CLAIMING FROM THE CHARGOR UNDER THIS SHARE CHARGE. THIS WAIVER APPLIES
     IRRESPECTIVE OF ANY LAW OR ANY PROVISION OF THIS SHARE CHARGE TO THE
     CONTRARY.

19.3 NON-COMPETITION

     UNTIL THE END OF THE SECURITY PERIOD, THE CHARGOR WILL NOT EXERCISE ANY
     RIGHTS WHICH IT MAY HAVE BY REASON OF PERFORMANCE BY IT OF ITS OBLIGATIONS
     UNDER THIS SHARE CHARGE:

     (A)  TO BE INDEMNIFIED BY THE BORROWER;

     (B)  TO CLAIM ANY CONTRIBUTION FROM ANY GUARANTOR OF ANY OBLIGATIONS UNDER
          THIS SHARE CHARGE; OR

     (C)  THE BENEFIT (IN WHOLE OR IN PART AND WHETHER BY WAY OF SUBROGATION OR
          OTHERWISE) OF ANY RIGHT OF THE SECURITY AGENT UNDER THIS SHARE CHARGE
          OR OF ANY OTHER GUARANTEE OR SECURITY TAKEN PURSUANT TO, OR IN
          CONNECTION WITH, THIS SHARE CHARGE BY THE SECURITY AGENT.

                                       15
<PAGE>

19.4 NO LIABILITY

     THE SECURITY AGENT AND ITS NOMINEE(S) WILL NOT BE LIABLE BY REASON OF
     TAKING ANY ACTION PERMITTED BY THIS SHARE CHARGE OR ANY NEGLECT OR DEFAULT
     IN CONNECTION WITH THE COLLATERAL OR TAKING POSSESSION OF OR REALISING ALL
     OR ANY PART OF THE COLLATERAL, EXCEPT IN THE CASE OF GROSS NEGLIGENCE OR
     WILFUL DEFAULT UPON ITS PART.

19.5 THIRD PARTY RIGHTS

     THE PARTIES TO THIS SHARE CHARGE DO NOT INTEND THAT ANY TERM OF THIS SHARE
     CHARGE SHOULD BE ENFORCEABLE, BY VIRTUE OF THE CONTRACTS (RIGHTS OF THIRD
     PARTIES) ACT 1999, BY ANY PERSON WHO IS NOT A PARTY TO THIS SHARE CHARGE.

19.6 COUNTERPARTS

     THIS SHARE CHARGE MAY BE EXECUTED IN ANY NUMBER OF COUNTERPARTS, AND THIS
     HAS THE SAME EFFECT AS IF THE SIGNATURES ON THE COUNTERPARTS WERE ON A
     SINGLE COPY OF THIS SHARE CHARGE.

20.  NOTICES

20.1 A DEMAND, NOTICE OR OTHER COMMUNICATION TO THE CHARGOR IN CONNECTION WITH
     THIS SHARE CHARGE:

          (I)  SHALL BE IN WRITING; AND

          (II) SHALL BE LEFT AT OR SENT BY FACSIMILE OR PREPAID ORDINARY POST
               (AIRMAIL IF POSTED TO A PLACE OUTSIDE THE UNITED KINGDOM) TO THE
               CHARGOR ADDRESSED TO THE PERSON AT THE ADDRESS IDENTIFIED WITH
               ITS SIGNATURE BELOW.

20.2 A DEMAND, NOTICE OR OTHER COMMUNICATION SHALL TAKE EFFECT FROM THE TIME IT
     IS RECEIVED (OR IF EARLIER THE TIME IT IS DEEMED TO BE RECEIVED IN
     ACCORDANCE WITH CLAUSE 20.3) UNLESS A LATER TIME IS SPECIFIED IN IT.

20.3 A LETTER OR FACSIMILE IS DEEMED TO BE RECEIVED:

          (I)  IN THE CASE OF A POSTED LETTER UNLESS ACTUALLY RECEIVED EARLIER
               ON THE SECOND (OR FIFTH, IF POSTED TO A PLACE OUTSIDE THE UNITED
               KINGDOM) DAY AFTER POSTING; AND

                                       16
<PAGE>

          (II) IN THE CASE OF FACSIMILE ON PRODUCTION OF A TRANSMISSION REPORT
               FROM THE MACHINE FROM WHICH THE FACSIMILE WAS SENT WHICH
               INDICATES THAT THE FACSIMILE WAS SENT IN ITS ENTIRETY TO THE
               FACSIMILE NUMBER OF THE RECIPIENT.

21.  GOVERNING LAW

21.1 GOVERNING LAW

     THIS DEED IS GOVERNED BY, AND WILL BE CONSTRUED IN ACCORDANCE WITH, ENGLISH
     LAW.

22.  JURISDICTION

22.1 SUBMISSION TO JURISDICTION

     THE CHARGOR IRREVOCABLY AGREES FOR THE BENEFIT OF THE SECURITY AGENT THAT
     THE COURTS OF ENGLAND AND/OR ANY OF THE FEDERAL OR STATE COURTS SITTING IN
     THE CITY OF NEW YORK, BOROUGH OF MANHATTAN WILL HAVE JURISDICTION TO HEAR
     AND DETERMINE ANY SUIT, ACTION OR PROCEEDING, AND TO SETTLE ANY DISPUTES
     WHICH MAY ARISE OUT OF, OR IN CONNECTION WITH, THIS SHARE CHARGE AND, FOR
     THAT PURPOSE, IRREVOCABLY SUBMITS TO THE JURISDICTION OF SUCH COURTS.

22.2 FORUM

     THE CHARGOR IRREVOCABLY WAIVES ANY OBJECTION WHICH IT MIGHT NOW OR
     HEREAFTER HAVE TO ANY OF THE COURTS REFERRED TO IN CLAUSE 22.1 BEING
     NOMINATED AS THE FORUM TO HEAR AND DETERMINE ANY SUIT, ACTION OR
     PROCEEDING, AND TO SETTLE ANY DISPUTES WHICH MAY ARISE OUT OF, OR IN
     CONNECTION WITH, THIS SHARE CHARGE AND AGREES NOT TO CLAIM THAT ANY SUCH
     COURT IS NOT A CONVENIENT OR INAPPROPRIATE FORUM.

22.3 OTHER COMPETENT JURISDICTIONS

     THE SUBMISSION TO THE JURISDICTION OF THE COURTS REFERRED TO IN CLAUSE 22.1
     WILL NOT (AND IS NOT TO BE CONSTRUED SO AS TO) LIMIT THE RIGHT OF THE
     SECURITY AGENT TO TAKE PROCEEDINGS AGAINST THE CHARGOR IN ANY OTHER COURT
     OF COMPETENT JURISDICTION, NOR WILL THE TAKING OF PROCEEDINGS IN ANY ONE OR
     MORE JURISDICTIONS PRECLUDE THE TAKING OF PROCEEDINGS IN ANY OTHER
     JURISDICTION, WHETHER CONCURRENTLY OR NOT.

22.4 CONSENT TO ENFORCEMENT

     THE CHARGOR HEREBY CONSENTS IN RESPECT OF ANY LEGAL ACTION OR PROCEEDING
     ARISING OUT OF, OR IN CONNECTION WITH, THIS SHARE CHARGE, TO THE GIVING OF
     ANY RELIEF, OR THE ISSUE OF ANY PROCESS IN

                                       17
<PAGE>

     CONNECTION WITH SUCH ACTION OR PROCEEDING INCLUDING, WITHOUT LIMITATION,
     THE MAKING, ENFORCEMENT OR EXECUTION AGAINST ANY PROPERTY WHATSOEVER
     (IRRESPECTIVE OF ITS USE OR INTENDED USE) OF ANY ORDER OR JUDGMENT WHICH
     MAY BE MADE OR GIVEN IN SUCH ACTION OR PROCEEDING.

22.5 WAIVER OF INDEMNITY

     TO THE EXTENT THAT THE CHARGOR MAY IN ANY JURISDICTION CLAIM FOR ITSELF OR
     ITS ASSETS, IMMUNITY FROM SUIT, EXECUTION, ATTACHMENT (WHETHER IN AID OF
     EXECUTION, BEFORE JUDGMENT OR OTHERWISE) OR OTHER LEGAL PROCESS AND, TO THE
     EXTENT THAT IN ANY SUCH JURISDICTION THERE MAY BE ATTRIBUTED TO ITSELF OR
     ITS ASSETS SUCH IMMUNITY (WHETHER OR NOT CLAIMED), THE CHARGOR HEREBY
     IRREVOCABLY AGREES THAT IT WILL NOT CLAIM, AND HEREBY IRREVOCABLY WAIVES,
     SUCH IMMUNITY TO THE FULL EXTENT PERMITTED BY THE LAW OF SUCH JURISDICTION.

23.  RELATIONSHIP WITH SECURITIES PURCHASE AGREEMENT - OVERRIDING PROVISIONS

23.1 IT IS ACKNOWLEDGED AND AGREED THAT:

     (A)  IF THERE IS ANY INCONSISTENCY OR CONFLICT BETWEEN THE PROVISIONS OF
          THIS SHARE CHARGE AND THOSE OF THE SECURITIES PURCHASE AGREEMENT,
          THEN, SUBJECT TO CLAUSE 23.1(B), THE PROVISIONS OF THE SECURITIES
          PURCHASE AGREEMENT SHALL PREVAIL;

     (B)  THE PROVISIONS OF CLAUSE 23.1(A) SHALL NOT APPLY SO AS TO OVERRIDE ANY
          PROVISIONS OF THIS SHARE CHARGE WHICH ARE NECESSARY TO ENABLE THE
          SECURITY AGENT TO ENFORCE THE SECURITY GRANTED BY THIS SHARE CHARGE IN
          ACCORDANCE WITH ITS TERMS; AND

     (C)  THE PROVISIONS OF THIS CLAUSE 23 SHALL OVERRIDE AND TAKE PRECEDENCE
          OVER ALL OTHER PROVISIONS IN THIS SHARE CHARGE IRRESPECTIVE OF THEIR
          TERMS.

THIS SHARE CHARGE HAS BEEN EXECUTED AS A DEED BY THE PARTIES LISTED IN THE
EXECUTION PAGE AT THE END OF THIS SHARE CHARGE ON THE DATE WRITTEN ON THE FIRST
PAGE OF THIS SHARE CHARGE.

                                       18
<PAGE>

                                 EXECUTION PAGES

IN WITNESS WHEREOF THIS SHARE CHARGE HAS BEEN EXECUTED THE DAY AND YEAR FIRST
BEFORE WRITTEN.

EXECUTED (BUT NOT DELIVERED UNTIL THE
DATE HEREOF BY MITEL NETWORKS
HOLDINGS LIMITED AND SIGNED BY
TWO DIRECTORS OR A DIRECTOR AND THE SECRETARY

                      DIRECTOR              /s/ Graham Bevington
                                               ----------------------
                                                Graham Bevington

                DIRECTOR                    /s/ Steve Spooner
                                               ----------------------
                                                Steve Spooner

NOTICE DETAILS

          ADDRESS:             MITEL BUSINESS PARK
                               PORTSKEWETT
                               CALDICOT
                               GWENT NP26 5YR
          FAX NO.:             0870 909 4040
          TEL. NO.:            0870 909 2020
          ATTENTION:           CHRIS CRANE

EXECUTED (BUT NOT DELIVERED UNTIL THE               HIGHBRIDGE INTERNATIONAL LLC
DATE HEREOF BY THE SECURITY AGENT
ACTING BY ITS DULY AUTHORIZED SIGNATORIES           BY: HIGHBRIDGE CAPITAL
                                                    MANAGEMENT, LLC

                                            BY:
                                               --------------------------------
                                                NAME: ARI J. STORCH
                                                TITLE: MANAGING DIRECTOR

                                       19
<PAGE>

                                 EXECUTION PAGES

IN WITNESS WHEREOF THIS SHARE CHARGE HAS BEEN EXECUTED THE DAY AND YEAR FIRST
BEFORE WRITTEN.

EXECUTED (BUT NOT DELIVERED UNTIL THE
DATE HEREOF BY MITEL NETWORKS
HOLDINGS LIMITED AND SIGNED BY
TWO DIRECTORS OR A DIRECTOR AND THE SECRETARY

                                                    DIRECTOR
                                                            -------------------

                                          DIRECTOR/SECRETARY
                                                            -------------------

NOTICE DETAILS

          ADDRESS:             MITEL BUSINESS PARK
                               PORTSKEWETT
                               CALDICOT
                               GWENT NP26 5YR
          FAX NO.:             0870 909 4040
          TEL. NO.:            0870 909 2020
          ATTENTION:           CHRIS CRANE

EXECUTED (BUT NOT DELIVERED UNTIL THE               HIGHBRIDGE INTERNATIONAL LLC
DATE HEREOF BY THE SECURITY AGENT
ACTING BY ITS DULY AUTHORIZED SIGNATORY             BY: HIGHBRIDGE CAPITAL
                                                    MANAGEMENT, LLC

                                                    BY: /s/ Adam J. Chill
                                                       -------------------------
                                                    NAME: ADAM J. Chill
                                                    TITLE: MANAGING DIRECTOR

                                       20
<PAGE>

MITEL NETWORKS LIMITED HEREBY ACKNOWLEDGES RECEIPT OF A COPY OF THE FOREGOING
SHARE CHARGE, AGREES PROMPTLY TO NOTE ON ITS BOOKS THE SECURITY INTERESTS
GRANTED UNDER SUCH SHARE CHARGE, AND WAIVES ANY RIGHTS OR REQUIREMENT AT ANY
TIME HEREAFTER TO RECEIVE A COPY OF SUCH SHARE CHARGE IN CONNECTION WITH THE
REGISTRATION OF ANY COLLATERAL IN THE NAME OF THE SECURITY AGENT OR ITS NOMINEE
OR THE EXERCISE OF VOTING RIGHTS BY THE SECURITY AGENT OR ITS NOMINEE.

EXECUTED AS A DEED BY )
MITEL NETWORKS        )
LIMITED               )
                      )
                      )
                         /s/ Graham Bevington
                         ------------------------------------
                         Director Graham Bevington

                         /s/ Steve Spooner

                         ------------------------------------
                         Director

                                       21<PAGE>
                                                                    Exhibit 4.52

            THIS TRI-PARTY AGREEMENT is made as of June 30, 2005

BETWEEN:

            MITEL NETWORKS OVERSEAS LIMITED, a corporation governed by the laws
            of Barbados,

            ("MNOL")

                                     - and -

            MITEL NETWORKS INTERNATIONAL LIMITED, a corporation governed by the
            laws of Barbados,

            ("MNIL")

                                     - and -

            MITEL NETWORKS LIMITED, a corporation governed by the laws of
            England and Wales,

            ("MNL")

RECITALS:

A.    Whereas MNOL (formerly Mitel Networks (Barbados) Limited) and MNIL have
      entered into an Intellectual Property License Agreement (the "MNOL License
      Agreement") dated April 28, 2001 providing for the granting of certain
      intellectual property licenses from MNOL to MNIL.

B.    Whereas MNIL and MNL have entered into an Intellectual Property License
      Agreement (the "MNIL License Agreement") dated April 28, 2001 providing
      for the granting of certain intellectual property licenses from MNIL to
      MNL.
<PAGE>
                                      -2-

C.    Whereas Mitel Networks Corporation ("MNC") issued certain senior secured
      convertible notes (the "Notes") pursuant to a securities purchase
      agreement (the "SPA") dated April 27, 2005 among MNC and the buyers from
      time to time signatory thereto (the "Buyers").

D.    Whereas pursuant to the SPA and in consideration for
      the Buyers purchasing the Notes, MNC and certain of
      its affiliates including MNL and MNOL have agreed to
      provide security in favour of the Buyers,

THEREFORE, in consideration of $10.00 and for other good and valuable
consideration (the sufficiency of which is hereby acknowledged) the Parties
agree as follows:

                                    ARTICLE 1
                  DEFINITIONS AND PRINCIPLES OF INTERPRETATION

1.1   DEFINITIONS

Whenever used in this Agreement, the following words and terms have the
following meanings:

      "AGREEMENT" means this agreement, including all schedules and all
      amendments, restatements, supplements and replacements as permitted, and
      references to "Article" or "Section" mean the specified Article or Section
      of this Agreement.

      "BUSINESS DAY" means any day other than Saturday, Sunday or other day on
      which commercial banks in the City of New York or the City of Ottawa,
      Canada are authorized or required by law to remain closed and which is
      also a day on which dealings in deposits are transacted in the London
      interbank market.

      "PERSON" means any individual, sole proprietorship, corporation, company,
      partnership, firm, entity, unincorporated association, unincorporated
      syndicate, unincorporated organization, trust, body corporate, government,
      government regulatory authority, governmental department, agency,
      commission, board, tribunal, dispute settlement panel or body, bureau,
      court, and where the context requires any of the foregoing when they are
      acting as trustee, executor, administrator or other legal representative.
<PAGE>
                                      -3-

1.2   CERTAIN RULES OF INTERPRETATION

In this Agreement:

      (a)   CONSENT -- Whenever a provision of this Agreement requires an
            approval or consent and the approval or consent is not delivered
            within the applicable time limit, then, unless otherwise specified,
            the Party whose consent or approval is required shall be
            conclusively deemed to have withheld its approval or consent.

      (b)   CURRENCY -- Unless otherwise specified, all references to money
            amounts are to the lawful currency of the United States.

      (c)   HEADINGS -- Headings of Articles and Sections are inserted for
            convenience of reference only and shall not affect the construction
            or interpretation of this Agreement.

      (d)   INCLUDING -- Where the word "including" or "includes" is used in
            this Agreement, it means "including (or includes) without
            limitation".

      (e)   NO STRICT CONSTRUCTION -- The language used in this Agreement is the
            language chosen by the Parties to express their mutual intent, and
            no rule of strict construction shall be applied against any Party.

      (f)   NUMBER AND GENDER -- Unless the context otherwise requires, words
            importing the singular include the plural and vice versa and words
            importing gender include all genders.

      (g)   TIME -- Time is of the essence in the performance of the Parties'
            respective obligations.

      (h)   TIME PERIODS -- Unless otherwise specified, time periods within or
            following which any payment is to be made or act is to be done shall
            be calculated by excluding the day on
<PAGE>
                                      -4-

            which the period commences and including the day on which the period
            ends and by extending the period to the next Business Day following
            if the last day of the period is not a Business Day.

                                    ARTICLE 2
                                   AMENDMENTS

2.1   MNOL LICENSE AGREEMENT

MNOL and MNIL hereby agree to amend the MNOL License Agreement such that:

      (a)   Section 7.4 is deleted in its entirety and replaced with the
            following:

            "7.4 TERMINATION - This Agreement may be terminated by:

            (i)   mutual agreement of the Parties in writing; or

            (ii)  at any time by MNOL upon the occurrence of an Event of Default
                  (as such term is defined in the Notes)."

      (b)   The following shall be added to the Definitions section as Section
            1.1(aa):

            " "NOTES" means the senior secured convertible notes issued pursuant
            to a securities purchase agreement dated April 27, 2005 among Mitel
            Networks Corporation and the buyers from time to time signatory
            thereto."

2.2   MNIL LICENSE AGREEMENT

MNIL and MNL hereby agree to amend the MNIL License Agreement such that Section
7.4 is deleted in its entirety and replaced with the following:

            "7.4 TERMINATION - This Agreement may be terminated by:

            (i)   mutual agreement of the Parties in writing; or

            (ii)  at any time by MNIL upon the occurrence of an Event of Default
                  (as such term is defined in the Notes)."

      (b)   The following shall be added to the Definitions section as Section
            1.1(aa):
<PAGE>
                                      -5-

            " "NOTES" means the senior secured convertible notes issued pursuant
            to a securities purchase agreement dated April 27, 2005 among Mitel
            Networks Corporation and the buyers from time to time signatory
            thereto."

2.3   ASSIGNMENT OF MNOL LICENSE AGREEMENT TO MNL

Prior to terminating the MNOL License Agreement in accordance with Section
7.4(ii) of such agreement, MNOL agrees to provide MNL or such other party as
Highbridge International LLC, as collateral agent for the Buyers, or any
successor collateral agent for the Buyers may direct with the option to have all
of the rights and obligations of MNOL under such agreement assigned to MNL or
such other party. In satisfaction of Section 8.1 of the MNOL License Agreement,
MNIL hereby irrevocably and unconditionally consents to any such assignment by
MNOL to MNL or such other party following the occurrence of an Event of Default
(as defined in the Notes).

                                    ARTICLE 3
                         REPERSENTATIONS AND WARRANTIES

3.1   REPRESENTATIONS AND WARRANTIES OF MNIL

MNIL represents and warrants to MNOL and MNL, the matters set out below.

      (a)   INCORPORATION AND CORPORATE POWER

            MNIL is a corporation validly existing under the laws of Barbados
            and has all necessary corporate power, authority and capacity to
            enter into this Agreement, to carry out its obligations under this
            Agreement, to own its assets and property and to carry on its
            business as presently conducted.

      (b)   DUE AUTHORIZATION AND ENFORCEABILITY OF OBLIGATIONS

            The execution and delivery of this Agreement and the consummation of
            the transactions contemplated by this Agreement have been duly
            authorized by all necessary corporate action on the part of MNIL.
            This Agreement constitutes a valid and binding obligation of MNIL
            enforceable against it in accordance with its terms.
<PAGE>
                                      -6-

      (c)   ABSENCE OF CONFLICTING AGREEMENTS

            MNIL is not a party to, bound or affected by or subject to any
            indenture, mortgage, lease, agreement, obligation, instrument,
            charter, by-law, order, judgment, decree, licence, law (including
            regulations) or governmental authorization that would be violated,
            breached by, or under which a default would occur or an encumbrance
            would be created, as a result of the execution and delivery of, or
            performance of obligations under, this Agreement or any other
            agreement to be entered into under the terms of this Agreement.

3.2   REPRESENTATIONS AND WARRANTIES OF MNOL

MNOL represents and warrants to MNIL and MNL, the matters set out below.

      (a)   INCORPORATION AND CORPORATE POWER

            MNOL is a corporation validly existing under the laws of Barbados
            and has all necessary corporate power, authority and capacity to
            enter into this Agreement, to carry out its obligations under this
            Agreement, to own its assets and property and to carry on its
            business as presently conducted.

      (b)   DUE AUTHORIZATION AND ENFORCEABILITY OF OBLIGATIONS

            The execution and delivery of this Agreement and the consummation of
            the transactions contemplated by this Agreement have been duly
            authorized by all necessary corporate action on the part of MNOL.
            This Agreement constitutes a valid and binding obligation of MNOL
            enforceable against it in accordance with its terms.

      (c)   ABSENCE OF CONFLICTING AGREEMENTS

            MNOL is not a party to, bound or affected by or subject to any
            indenture, mortgage, lease, agreement, obligation, instrument,
            charter, by-law, order, judgment, decree, licence, law (including
            regulations) or governmental
<PAGE>
                                      -7-

            authorization that would be violated, breached by, or under which a
            default would occur or an encumbrance would be created, as a result
            of the execution and delivery of, or performance of obligations
            under, this Agreement or any other agreement to be entered into
            under the terms of this Agreement.

3.3   REPRESENTATIONS AND WARRANTIES OF MNL

MNL represents and warrants to MNOL and MNIL, the matters set out below.

      (a)   INCORPORATION AND CORPORATE POWER

            MNL is a corporation validly existing under the laws of England and
            Wales and has all necessary corporate power, authority and capacity
            to enter into this Agreement, to carry out its obligations under
            this Agreement, to own its assets and property and to carry on its
            business as presently conducted.

      (b)   DUE AUTHORIZATION AND ENFORCEABILITY OF
            OBLIGATIONS

            The execution and delivery of this Agreement and the consummation of
            the transactions contemplated by this Agreement have been duly
            authorized by all necessary corporate action on the part of MNL.
            This Agreement constitutes a valid and binding obligation of MNL
            enforceable against it in accordance with its terms.

      (c)   ABSENCE OF CONFLICTING AGREEMENTS

            MNL is not a party to, bound or affected by or subject to any
            indenture, mortgage, lease, agreement, obligation, instrument,
            charter, by-law, order, judgment, decree, licence, law (including
            regulations) or governmental authorization that would be violated,
            breached by, or under which a default would occur or an encumbrance
            would be created, as a result of the execution and delivery of, or
            performance of obligations under, this Agreement or any other
            agreement to be entered into under the terms of this Agreement.
<PAGE>
                                      -8-

                                    ARTICLE 4
                                     GENERAL

4.1   EFFECT OF AGREEMENT

This Agreement shall enure to the benefit of, and be binding upon, the Parties
hereto and their respective successors and permitted assigns.

4.2   FURTHER ASSURANCES

The Parties hereto agree to sign all such further documents and do all such
further things as may be deemed necessary or appropriate to give full effect to
this Agreement.

4.3   SEVERABILITY

If any term, clause, or provision of this Agreement shall be judged to be
invalid or unenforceable, the validity or enforceability of any other term,
clause or provision shall not be affected, and such invalid or unenforceable
term, clause or provisions shall be replaced with an enforceable clause which
most closely achieves the result intended by the invalid clause.

4.4   AMENDMENT

Any amendment, supplement, replacement or modification to this Agreement must be
made in writing and signed by all Parties and shall require the prior written
consent of a majority of the holders of the Notes.

4.5   GOVERNING LAW

All issues and questions concerning the construction, validity, enforcement and
interpretation of this Agreement shall be governed by, and construed in
accordance with, the laws of Barbados, without giving effect to any choice of
law or conflict of laws, rules or provisions.

4.6   JURISDICTION

The Parties hereby submit and consent to the exclusive jurisdiction of the
courts located in Barbados.
<PAGE>
                                      -9-

4.7   ENTIRE AGREEMENT

This Agreement constitutes the entire agreement between the Parties with respect
to the subject matter hereof.

4.8   NOTICES

Any notice, consent or approval required or permitted to be given in connection
with this Agreement (in this Section referred to as a "Notice") shall be in
writing and shall be sufficiently given if delivered (whether in person, by
courier service or other personal method of delivery), or if transmitted by
facsimile:

      (a)   in the case of a Notice to MNIL at:

                  Mitel Networks International Limited
                  Whitepark House
                  White Park Road
                  Bridgetown, Barbados

                  Attention:  Counsel

                  Fax:        (246) 429-2677

      (b)   in the case of a Notice to MNOL at:

                  Mitel Networks Overseas Limited
                  Whitepark House
                  White Park Road
                  Bridgetown, Barbados

                  Attention:  Counsel

                  Fax:        (246) 429-2677

      (c)   in the case of a Notice to MNL at:

                  Mitel Networks Limited
                  Mitel Business Park
                  Portskewett, Caldicott
                  NPZ6 5YR  U.K.
<PAGE>
                                      -10-

                  Attention:  Counsel

                  Fax:        0870-909-4040

Any Notice delivered or transmitted to a Party as provided above shall be deemed
to have been given and received on the day it is delivered or transmitted,
provided that it is delivered or transmitted on a Business Day prior to 5:00
p.m. local time in the place of delivery or receipt. However, if the Notice is
delivered or transmitted after 5:00 p.m. local time or if the day is not a
Business Day then the Notice shall be deemed to have been given and received on
the next Business Day.

Any Party may, from time to time, change its address by giving Notice to the
other Parties in accordance with the provisions of this Section.

4.9   EXECUTION AND DELIVERY

This Agreement may be executed by the Parties in counterparts and may be
executed and delivered by facsimile and all the counterparts and facsimiles
shall together constitute one and the same agreement.

[REMAINDER OF PAGE INTENTIONALLY LEFT BLANK; SIGNATURE BLOCKS FOLLOW.]
<PAGE>
                                      -11-

IN WITNESS OF WHICH the Parties have duly executed this Agreement.

                                         MITEL NETWORKS LIMITED

                                         By:
                                              ----------------------------------
                                              Name: -
                                              Title: -
<

                                         MITEL NETWORKS INTERNATIONAL LIMITED

                                         By:
                                              ----------------------------------
                                              Name: -
                                              Title: -

                                         MITEL NETWORKS OVERSEAS LIMITED

                                         By:
                                              ----------------------------------
                                              Name: -
                                              Title: -

Source: [{"source": "alea-institute/alea-institute/kl3m-data-edgar-agreements/train-00111-of-00352.parquet"}, [{"source": "alea-institute/alea-institute/kl3m-data-edgar-agreements/train-00111-of-00352.parquet"}]]