<PAGE>   1
                                                                    EXHIBIT 4.19


              NWE CYPRUS SENIOR NOTE SECURITY AND PLEDGE AGREEMENT


         THIS NWE CYPRUS SENIOR NOTE SECURITY AND PLEDGE AGREEMENT (the
"Security Agreement") is made and entered into as of May 31, 1996 by NWE CAPITAL
(CYPRUS), LIMITED, a Cypriot corporation (the "Company"), in favor of THE BANK
OF NEW YORK, a New York banking corporation, as trustee (in such capacity, the
"Senior Note Trustee") under the Senior Note Indenture (as defined herein) for
the holders of the Senior Notes (as defined herein), THE BANK OF NEW YORK, a New
York banking corporation, as trustee (in such capacity, the "Convertible Note
Trustee") under the Convertible Note Indenture (as defined herein) for the
holders of the Convertible Notes (as hereinafter defined) and THE BANK OF NEW
YORK, as collateral agent (in such capacity, the "Collateral Agent").

                                   WITNESSETH:

         WHEREAS, Petersburg Long Distance Inc., an Ontario corporation, as
issuer (the "Issuer"), the Senior Note Trustee, and the Company, PLD Asset
Leasing Limited, a Cypriot corporation ("PLD Asset"), PLD Capital Limited, a
Cypriot corporation ("PLD Capital together with PLD Asset, the "Leasing
Companies"), Baltic Communications Limited, a Russian joint stock company of the
closed type ("BCL"), and Wireless Technology Corporations Limited, a British
Virgin Islands corporation ("WTC"), as Guarantors (the "Senior Note
Guarantors"), have entered into an indenture dated as of May 31, 1996 (as
amended, amended and restated, supplemented or otherwise modified from time to
time, the "Senior Note Indenture") pursuant to which the Company is issuing
$123,000,000 in aggregate principal amount at Stated Maturity of its 14% Senior
Discount Notes due 2004 (the "Senior Notes"); and

         WHEREAS, the Company, as issuer, the Convertible Note Trustee, and NWE
Cyprus, the Leasing Companies, WTC and BCL, as guarantors (the "Convertible Note
Guarantors"), have entered into an indenture dated as of May 31, 1996 (as
amended, amended and restated, supplemented or otherwise modified from time to
time, the "Convertible Note Indenture") pursuant to which the Company is issuing
$26,500,000 in aggregate principal amount of its 9% Convertible Notes due 2006
(the "Convertible Notes"); and

         WHEREAS, to secure its obligations under the Senior Note Indenture and
its Senior Note Guarantee and the other Collateral Documents (as defined in the
Senior Note Indenture) (together with the Issuer's obligations under the Senior
Notes, the Senior Note Indenture, and the Senior Note Collateral Documents and
the other Senior Note Guarantors' obligations under the Senior Note Indenture,
the guarantees contained therein (the "Senior Note Guarantees") and the Senior
Note Collateral Documents, the
<PAGE>   2
"Senior Note Obligations"), and to secure its obligations under the Convertible
Note Indenture and the Convertible Notes and the other Convertible Note
Collateral Documents (as defined in the Senior Note Indenture) (together with
the Convertible Note Guarantors' obligations under the Convertible Note
Indenture, the guarantees contained therein (the "Convertible Note Guarantees")
and the Convertible Note Collateral Documents, the "Convertible Note
Obligations"), the Issuer has agreed to cause the Company (i) to grant to the
Collateral Agent for the benefit of the Senior Note Trustee and the equal and
ratable benefit of the holders of the Senior Notes and for the benefit of the
Convertible Note Trustee and for the equal and ratable benefit of the Holders of
the Convertible Notes, Liens and security interests in and to the Collateral (as
defined herein) and (ii) to execute and deliver this Security Agreement in order
to secure the payment and performance by the Company of the Senior Note
Obligations and the Convertible Note Obligations (collectively, the
"Obligations").

                                    AGREEMENT

         NOW, THEREFORE, in consideration of the premises and in order to induce
the Holders of the Senior Notes to purchase the Senior Notes and the Holders of
the Convertible Notes to purchase the Convertible Notes, the Company hereby
agrees with the Collateral Agent, with the Senior Note Trustee for its benefit
and the equal and ratable benefit of the Holders of the Senior Notes and with
the Convertible Note Trustee for its benefit and the equal and ratable benefit
of the Holders of the Convertible Notes as follows:

         SECTION 1. DEFINITIONS. Capitalized terms used herein and not otherwise
defined herein shall have the meaning given to such terms in the Senior Note
Indenture. In addition to any other defined terms used herein, the following
terms shall constitute defined terms for the purposes of this Security
Agreement: 

                  "Default" means a "Default" as defined in Section 1.1 of the
         Senior Note Indenture until the Senior Notes are no longer outstanding
         and the Senior Note Indenture has been satisfied and discharged, in
         which case a "Default" means a "Default" as defined in Section 1.1 of
         the Convertible Note Indenture if not then satisfied and discharged.

                  "Event of Default" means an "Event of Default" as defined in
         Section 1.1 of the Senior Note Indenture until the Senior Notes are no
         longer outstanding and the Senior Note Indenture has been satisfied and
         discharged, in which case "Event of Default" means an "Event of
         Default" as defined in Section 1.1 of the Convertible Note Indenture if
         not then satisfied and discharged.


                                       2
<PAGE>   3
                  "Permitted Liens" means "Permitted Liens" as defined in
         Section 1.1 of the Senior Note Indenture until the Senior Notes are no
         longer outstanding and the Senior Note Indenture has been satisfied and
         discharged, in which case "Permitted Liens" means "Permitted Liens" as
         defined in Section 1.1 of the Convertible Note Indenture.

                  "Trustees" means, collectively, the Senior Note Trustee and
         the Convertible Note Trustee.


         SECTION 2. CREATION OF SECURITY INTEREST. The Company hereby grants to
the Collateral Agent for the benefit of the Senior Note Trustee and for the
equal and ratable benefit of the Holders of the Senior Notes and for the benefit
of the Convertible Note Trustee and for the equal and ratable benefit of the
Holders of the Convertible Notes, Liens and a continuing security interest in
and to the collateral described in Section 3 hereof (the "Collateral") in order
to secure the payment and performance of all Obligations.

         SECTION 3. COLLATERAL.  The Collateral is:

              (a)  WTC Capital Stock. All Capital Stock of WTC, whether now
owned or hereafter acquired ("WTC Capital Stock"), including those shares of
Capital Stock of WTC listed on Schedule A attached hereto, and the certificates
representing the Capital Stock of WTC, and all products and proceeds of any of
the Capital Stock of WTC, including, without limitation, all dividends, cash,
options, warrants, rights, instruments, subscriptions and other property or
proceeds from time to time received, receivable or otherwise distributed in
respect of or in exchange for any or all of the WTC Capital Stock; and all
additional shares of and all securities convertible into, and warrants, options
or other rights to purchase, stock of, or an equity interest in, WTC from time
to time acquired by the Company in any manner, and the certificates representing
such additional shares (any such additional shares shall constitute part of the
WTC Capital Stock under and as defined in this Security Agreement), and all
products and proceeds of any such additional WTC Capital Stock, including,
without limitation, all dividends, cash, options, warrants, rights, instruments,
subscriptions, and other property or proceeds from time to time received,
receivable or otherwise distributed in respect of or in exchange for any or all
of such additional WTC Capital Stock including all proceeds received or
receivable by the Company from any recapitalization, reclassification, merger,
dissolution, liquidation or other termination of the existence of WTC.

              (b)  Intercompany Notes. All Intercompany Notes, whether executed
on the Issue Date or thereafter, from any Restricted Subsidiary, evidencing
loans or advances made by the


                                        3
<PAGE>   4
Company, all Liens securing such Intercompany Notes and the related collateral
documents, and the instruments representing such Intercompany Notes, and, except
as otherwise provided elsewhere herein, all products and proceeds of such
Intercompany Notes, including, without limitation, all interest and principal
payments, instruments, and other property from time to time received, receivable
or otherwise distributed in respect of or in exchange for such Intercompany
Notes; and

              (c)  After-acquired Collateral and Proceeds. All items described
in this Section 3 (other than those items specifically excluded), whether now
owned or hereafter, at any time acquired by the Company and wherever located,
including (except as otherwise provided herein) all replacements, additions,
accessions, substitutions, repairs, proceeds and products relating thereto or
therefrom, and all documents, ledger sheets, files, books and records of the
Company relating thereto. Proceeds hereunder include (i) whatever is now or
hereafter received by the Company upon the sale, exchange, collection or other
disposition of any item of Collateral; (ii) any property of the type or types
described in subsection (a) now or hereafter acquired by the Company with any
proceeds of Collateral hereunder; and (iii) any payments under any insurance or
any indemnity, warranty or guaranty, payable by reason of loss or damage to or
otherwise with respect to any of the foregoing Collateral.

         SECTION 4. DELIVERY OF COLLATERAL. All certificates or instruments
representing or evidencing the Collateral shall be delivered to and held by or
on behalf of the Collateral Agent pursuant hereto and shall be in suitable form
for transfer by delivery, or shall be accompanied by duly executed instruments
of transfer or assignment in blank, all in form and substance satisfactory to
the Collateral Agent, and shall be accompanied by any required transfer tax
stamps. Upon the occurrence and continuance of an Event of Default, the
Collateral Agent shall have the right, at any time in its discretion and without
notice to the Company but subject to its compliance with the requirements of
applicable law, to transfer to or to register in the name of the Collateral
Agent or any of its nominees any or all of the Collateral. In addition, upon the
occurrence and during the continuance of an Event of Default, but subject to its
compliance with the requirements of applicable law, the Collateral Agent shall
have the right at any time to exchange certificates or instruments representing
or evidencing Collateral for certificates or instruments of smaller or larger
denominations.

         SECTION 5. REPRESENTATIONS AND WARRANTIES. The Company hereby
represents and warrants to the Collateral Agent and the Trustees that, except as
specified in Schedule B attached hereto:


                                        4
<PAGE>   5
              (a)  Legal Power. The execution, delivery and performance by the
Company of this Security Agreement are within the Company's legal powers, have
been duly authorized by all necessary corporate action, require no action by or
in respect of, or filing with (except for any filings provided for hereunder),
any governmental authority, require no consent of any other Person and do not
contravene, or constitute a default under, any provision of applicable law or
regulation or of the articles of incorporation or bylaws of the Company or of
any agreement (after giving effect to the use of proceeds of the issuance of the
Senior Notes), judgment, injunction, order, decree or other instrument binding
upon the Company or result in the creation or imposition of any Lien on any
asset of the Company (other than the Liens created by this Security Agreement,
and the Senior Note Collateral Documents.

              (b)  WTC Capital Stock. The WTC Capital Stock has been duly
authorized and validly issued and is fully paid and non-assessable. The WTC
Capital Stock constitutes and will at all times constitute all of the authorized
issued and outstanding Capital Stock of WTC beneficially owned by the Company.

              (c)  Title to Collateral. The Company is the legal, record and
beneficial owner of the WTC Capital Stock existing on the Issue Date (the
"Existing Collateral"), free and clear of any Lien or claims of any person
except the Liens created by this Security Agreement and any of the other Senior
Note Collateral Documents.

              (d)  Enforceability. This Security Agreement has been duly
executed and delivered by the Company and constitutes a legal, valid and binding
obligation of the Company, enforceable against the Company in accordance with
its terms, except as such enforceability may be limited by the effect of any
applicable bankruptcy, insolvency, reorganization, moratorium or other similar
laws affecting creditors' rights generally or general principles of equity and
commercial reasonableness and except that a Canadian court will only render
judgment in Canadian currency.


              (e)  Perfection; Priority. Upon the delivery to the Collateral
Agent of the Existing Collateral and the filing of the Senior Note Collateral
Documents and the documents listed on Schedule C attached hereto, to the extent
such security interest is created under applicable Federal and New York law, the
security interest in the Collateral created pursuant to this Security Agreement
creates a valid and perfected first priority security interest in the Existing
Collateral, securing the payment of the Obligations to the Collateral Agent for
the benefit of the Senior Note Trustee and the Holders of the Senior Notes and
the Convertible Note Trustee and the Holders of the Convertible Notes, and
enforceable as such against all creditors


                                                         5
<PAGE>   6
of the Company and any Persons purporting to purchase any of the Collateral from
the Company, other than as permitted by the Senior Note Indenture, as of the
date hereof (and after giving effect to the use of proceeds of the issuance of
the Senior Notes), there are no other security interests in or Liens on the
Existing Collateral or any portion thereof, and no financing statement, pledge,
notice of Lien, assignment or collateral assignment, mortgage or deed of trust
covering the Collateral or any portion thereof ("Lien Notice") exists or is on
file in any public office, except with respect to the Liens created by this
Security Agreement and Liens to be released in connection with the use of
proceeds of the issuance of the Senior Notes.

              (f)  Offices. The Company's chief executive offices are located at
the address shown as the chief executive office in Schedule D attached hereto
("Chief Executive Office"), and the Company has no places of business other than
those set forth in such Schedule D, except as permitted hereafter by Section
6(c) hereof.

              (g)  Business Names. The Company has not conducted its businesses
under any corporate, partnership or fictitious name during the five (5) years
preceding the date hereof, other than those names set forth on Schedule E
attached hereto.

              (h)  No Consents. No consent of any other person and no consent,
authorization, approval, or other action by, and no notice to or filing with,
any governmental authority or regulatory body is required either (i) for the
granting of the Liens by the Company on the Collateral pursuant to this Security
Agreement or for the execution, delivery or performance of this Security
Agreement by the Company (except for filings listed on Schedule C attached
hereto, the filings and/or other actions necessary to maintain the perfection of
the Liens on the Existing Collateral and perfect Liens on after-acquired
Collateral or the proceeds of the Collateral) or (ii) for the exercise by the
Collateral Agent of the voting or other rights provided for in this Security
Agreement or the remedies in respect of the Collateral pursuant to this Security
Agreement, except, in each case, as may be required in connection with any such
disposition by laws affecting the offering and sale of the WTC Capital Stock
constituting Collateral.

              (i)  Litigation. No litigation, investigation or proceeding of or
before any arbitrator or governmental authority is pending or, to the knowledge
of the Company, threatened by or against the Company with respect to this
Security Agreement or any of the transactions contemplated hereby.

         SECTION 6. COVENANTS.


                                        6
<PAGE>   7
              (a)  Lien Notices. The Company will defend its interest in the
Collateral against all claims and demands of all persons at any time claiming
the same or any interest therein and the Company will not permit any Lien
Notices with respect to the Collateral or any portion thereof to exist or be on
file in any public office for more than 30 days after the Company shall have
notice thereof, except with respect to Permitted Liens. The Company will advise
the Collateral Agent and the Trustees promptly, in reasonable detail, at the
addresses specified in Section 17(a) of this Security Agreement, of any Lien
(other than Permitted Liens) on, or claim asserted against, any of the
Collateral.

              (b)  Location of Collateral. The Company will keep all of its
Collateral now held or subsequently acquired by it at the locations specified on
Schedule F hereto, or at locations hereafter established in compliance with
Section 6(c) hereof (except for Collateral held by the Collateral Agent, a
Trustee or the Escrow Agent), unless the Company shall have given the Collateral
Agent and the Trustees prior written notice thereof and shall have in advance
executed and caused to be filed and/or delivered to the Collateral Agent and the
Trustees any financing statements or other documents required by the Collateral
Agent and the Trustees in order to perfect, protect and preserve the Liens and
security interest created hereby, all in form and substance satisfactory to the
Collateral Agent and the Trustees.

              (c)  Location of Offices; Corporation Name; Legal Structure. The
Company will not change the location of its chief executive office or establish
any place of business other than those set forth on Schedule D attached hereto,
or voluntarily or involuntarily change its name, identity or legal structure,
including without limitation any continuances, amalgamation, merger,
consolidation or sale of substantially all of its assets, unless the Company
shall have given the Collateral Agent and the Trustees at least thirty (30) days
prior written notice thereof and shall have in advance executed and caused to be
filed and/or delivered to the Collateral Agent and the Trustees any financing
statements or other Collateral Documents required by the Collateral Agent and
the Trustees in order to perfect, protect and preserve the Liens and security
interest created hereby, all in form and substance satisfactory to the Trustees
and the Collateral Agent.

              (d)  Additional Collateral; Further Assurances. The Company agrees
that immediately upon becoming the beneficial owner of any additional shares of
WTC Capital Stock constituting Collateral or Intercompany Notes constituting
Collateral, it will pledge and deliver to the Collateral Agent for the benefit
of the Senior Note Trustee and the equal and ratable benefit of the Holders of
the Senior Notes and for the benefit of the Convertible Note Trustee and for the
equal and ratable benefit of


                                        7
<PAGE>   8
the Holders of the Convertible Notes, the certificates, instruments and
documents representing such WTC Capital Stock (as well as duly executed
instruments of transfer or assignment in blank), and grant to the Collateral
Agent for the benefit of the Senior Note Trustee and the equal and ratable
benefit of the Holders of the Senior Notes and for the benefit of the
Convertible Note Trustee and for the equal and ratable benefit of the Holders of
the Convertible Notes pursuant to appropriate and necessary Collateral
Documents, a continuing first priority security interest in and Liens on, such
WTC Capital Stock and Intercompany Notes, all in form and substance satisfactory
to the Collateral Agent and the Trustees (as well as duly executed instruments
of transfer or assignment in blank), and grant to the Collateral Agent for the
benefit of the Senior Note Trustee and the equal and ratable benefit of the
Holders of the Senior Notes and for the benefit of the Convertible Note Trustee
and for the equal and ratable benefit of the Holders of the Convertible Notes
pursuant to appropriate and necessary Senior Note Collateral Documents, a
continuing first priority security interest in and Liens on such WTC Capital
Stock or such Intercompany Notes, all in form and substance satisfactory to the
Collateral Agent and the Trustees. The Company shall also promptly (and in any
event within five (5) Business Days after receipt thereof), subject to its
compliance with the requirements of applicable law, deliver to the Collateral
Agent any other documents of title, promissory notes, certificates or
instruments representing Collateral which it holds. The Company further agrees
that it will promptly (and in any event within five (5) Business Days after such
acquisition) deliver to the Collateral Agent and the Trustees an amendment, duly
executed by the Company, in substantially the form of Schedule G hereto an
"Additional Collateral Amendment", with respect to the additional Collateral
that is to be pledged pursuant to this Security Agreement. The Company hereby
authorizes the Collateral Agent and the Trustees to attach each Additional
Collateral Amendment to this Security Agreement and agrees that any stock, notes
or other forms of Investments listed on any Additional Collateral Amendment
delivered to the Collateral Agent or the Trustees shall for all purposes
hereunder be considered Collateral. The Company will, promptly, (i) execute and
deliver, cause to be executed and filed, or use its best efforts to give any
notices, in all appropriate jurisdictions (including British Virgin Islands,
Canada, Cyprus, the Russian Federation, Kazakstan and Ireland) or procure any
financing statements, assignments, pledges or other documents, (ii) mark any
chattel paper constituting Collateral, deliver any certificates, chattel paper
or instruments constituting Collateral to the Collateral Agent or the Trustees,
(iii) to execute and deliver or cause to be executed and delivered all stock
powers, proxies, assignments, instruments and other documents, and (iv) take any
other actions that are necessary or, in the reasonable opinion of Collateral
Agent or the Trustees, desirable to perfect or continue the perfection and the
priority


                                        8
<PAGE>   9
of the Collateral Agent's security interest and Liens in the Collateral, to
protect the Collateral against the rights, claims, or interests of third Persons
other than holders of Permitted Liens or to effect the purposes of this Security
Agreement. The Company also hereby authorizes the Collateral Agent to file any
financing or continuation statements with respect to the Collateral without the
signature of the Company to the extent permitted by applicable law.


              (e)  Disposition of Collateral. The Company will not sell,
transfer, assign, pledge, collaterally assign, exchange or otherwise dispose of,
or grant any option or warrant with respect to, any of the Collateral except as
permitted by the Senior Note Indenture and the Convertible Note Indenture. If
the proceeds of any sale of any Collateral are notes, instruments, documents of
title, standby letters of credit or chattel paper, such proceeds shall be
promptly delivered to the Collateral Agent to be held as Collateral hereunder.
If the Collateral, or any part thereof, is sold, transferred, assigned,
exchanged, or otherwise disposed of in violation of these provisions, the
security interest and Liens of the Collateral Agent shall continue in such
Collateral or part thereof notwithstanding such sale, transfer, assignment,
exchange or other disposition, and the Company will hold the proceeds thereof in
a separate account for the benefit of the Senior Note Trustee and the Holders of
the Senior Notes and the benefit of the Convertible Note Trustee and the Holders
of the Convertible Notes and transfer such proceeds to the Collateral Agent or
the applicable Trustee in kind to be held as Collateral hereunder.


              (f)  Restrictive Agreements. The Company agrees that, except for
existing agreements set forth on Schedule H attached hereto, it will not (i)
enter into any agreement or understanding that purports to or may restrict or
inhibit the Collateral Agent's or the Trustees' rights or remedies hereunder,
including, without limitation, the Trustees' right to sell or otherwise dispose
of the Collateral or amend or modify in any manner materially adverse to the
Trustees the existing agreements set forth as Schedule G attached hereto, (ii)
permit WTC or any other relevant issuer to continue, merge, amalgamate or
consolidate, unless all outstanding Capital Stock owned by the Company of the
surviving corporation is, upon such continuance, merger, amalgamation or
consolidation, pledged hereunder to the Collateral Agent or (iii) fail to pay or
discharge any tax, assessment or levy of any nature not later than five days
prior to the date of any proposed sale under any judgment, writ or warrant of
attachment with regard to the Collateral.


              (g)  Rights of Collateral Agent and Trustees. Upon the occurrence
and during the continuance of an Event of Default, the Collateral Agent and the
Senior Note Trustee (or the Convertible Note Trustee if the Senior Notes are no
longer outstanding and the Senior Note Indenture has been satisfied and
discharged)


                                        9
<PAGE>   10
shall have the right at any time to make any payments and do any other acts the
Collateral Agent or the applicable Trustee may deem necessary to protect its
Liens and security interest in the Collateral, including, without limitation,
the rights to pay, purchase, contest or compromise any Lien which, in the
judgment of the Collateral Agent or such Trustee, appears to be prior to or
superior to the Liens and security interest granted hereunder, and challenge any
action or proceeding purporting to affect its Liens and security interest in the
Collateral. The Company hereby agrees to reimburse the Collateral Agent and the
Trustees for all payments made and expenses incurred under this Security
Agreement including reasonable fees, expenses and disbursements of attorneys and
paralegals acting for the Collateral Agent or the Trustees, including any of the
foregoing payments under or acts taken to perfect or protect the Liens and
security interest in the Collateral, which amounts shall be secured under this
Security Agreement, and agrees that it shall be bound by any payment made or act
taken by the Collateral Agent or the Trustees hereunder. Neither the Collateral
Agent nor the Trustees shall have any obligation to make any of the foregoing
payments or perform any of the foregoing acts.

              (h)  Records. The Company will keep and maintain at its own cost
and expense satisfactory and complete records of the Collateral.

              (i)  Access. On reasonable notice to the Company, except at any
time during the continuation of Default or an Event of Default, both the
Collateral Agent and the Trustees shall at all times have full and free access
during normal business hours to all the books, correspondence and records of the
Company relating to the Collateral, and the Collateral Agent and its
representatives, and the Trustees and their respective representatives, may
examine the same, take extracts therefrom and make photocopies thereof, and the
Company agrees to render to the Collateral Agent and/or the applicable Trustee,
at the Company's cost and expense, such clerical and other assistance, at all
times and in such manner as may be requested with regard thereto. On reasonable
notice to the Company, except at any time during the continuation of Default or
an Event of Default, the Collateral Agent and its representatives, and the
Trustee and their respective representatives, shall at all times also have the
right to enter, during normal business hours, into and upon any premises where
any of the Collateral is located for the purpose of inspecting the same,
observing its use or otherwise protecting its interests therein.

              (j)  Taxes. The Company shall pay all taxes, assessments and
government charges and all claims as and to the extent required by Section 4.6
of each of the Senior Note Indenture and the Convertible Note Indenture;
provided that the Company shall in any event pay such taxes, assessments or
levies


                                       10
<PAGE>   11
not later than five days prior to the date of any proposed sale under any
judgment, writ or warrant of attachment with regard to any Collateral of the
Company entered or filed against the Company as a result of the failure to make
such payment.

         SECTION 7. VOTING RIGHTS; DIVIDENDS; ETC.

              (a)  So long as no Event of Default shall have occurred and be
continuing, the Company shall be entitled to exercise any and all voting and
other consensual rights pertaining to the WTC Capital Stock or Intercompany
Notes constituting Collateral or any part thereof for any purpose not
inconsistent with the terms of this Security Agreement, the Senior Note
Indenture or any other Senior Note Collateral Document or the Convertible Note
Indenture or any Convertible Note Collateral Document; provided that the Company
shall not exercise or shall refrain from exercising any such right if such
action would be inconsistent with or violate any provisions of this Security
Agreement, the Senior Note Indenture or any other Senior Note Collateral
Document or the Convertible Note Indenture or any Convertible Note Collateral
Document.

              (b)  So long as no Event of Default shall have occurred and be
continuing, and subject to the other terms and conditions hereof and of the
Senior Note Indenture, or of the Convertible Note Indenture, the Company shall
be entitled to receive, and to utilize free and clear of the Lien of this
Security Agreement, all payments made from time to time in respect of the WTC
Capital Stock or Intercompany Notes, whether dividends, distributions or
otherwise.

              (c)  The Collateral Agent and/or the Senior Note Trustee (or the
Convertible Note Trustee if the Senior Notes are no longer outstanding and the
Senior Note Indenture has been satisfied and discharged) shall execute and
deliver (or cause to be executed and delivered) to the Company all such proxies
and other instruments as the Company may reasonably request for the purpose of
enabling the Company to exercise the voting and other rights that it is entitled
to exercise pursuant to Section 7(a) above.

              (d)  Upon the occurrence and during the continuance of an Event of
Default, (i) all rights of the Company to exercise the voting and other
consensual rights that it would otherwise be entitled to exercise pursuant to
Section 7(a) shall cease, and all such rights shall thereupon become vested in
the Collateral Agent on behalf of, or if necessary, directly in, the Senior Note
Trustee (or the Convertible Note Trustee if the Senior Notes are no longer
outstanding and the Senior Note Indenture has been satisfied and discharged),
which shall thereupon have the sole right to exercise such voting and other
consensual rights; and (ii) all interest, principal payments, dividends or other


                                       11
<PAGE>   12
distributions payable or other payments made in respect of the Collateral shall
constitute Collateral and shall be paid directly to the Collateral Agent and the
Company's right to receive such payments pursuant to Section 7(d) hereof shall
immediately cease and all such payments shall be deposited in the Company Senior
Note Escrow Account or the Convertible Note Escrow Account, if the Company
Senior Note Escrow Account Agreement has been terminated.

              (e)  Upon the occurrence and during the continuance of an Event of
Default, the Company shall execute and deliver (or cause to be executed and
delivered) to the Collateral Agent and/or the Senior Note Trustee (or the
Convertible Note Trustee if the Senior Notes are no longer outstanding and the
Senior Note Indenture has been satisfied and discharged) all such proxies and
other instruments as the Collateral Agent and/or the applicable Trustee may
reasonably request for the purpose of enabling the Collateral Agent and/or the
applicable Trustee to exercise the voting and other rights that it is entitled
to exercise pursuant to Section 7(d) above.

              (f)  All dividends and distributions and all other payments that
are received by the Company contrary to the provisions of this Section 7 shall
be received in trust for the Collateral Agent for the benefit of the Senior Note
Trustee and the equal and ratable benefit of the Holders of the Senior Notes and
for the benefit of the Convertible Note Trustee and the equal and ratable
benefit of the Holders of the Convertible Notes, shall be segregated from the
other property or funds of the Company and be forthwith delivered to the
Collateral Agent as Collateral in the same form as so received (with any
necessary endorsements or other instruments of transfer or assignment in blank),
and all such payments shall be deposited in the Company Senior Note Escrow
Account or the Company Convertible Note Escrow Account if the Company Senior
Note Escrow Account Agreement has been terminated.

              (g)  So long as no Event of Default shall have occurred and be
continuing, neither the Collateral Agent nor the Trustees shall be under any
obligation to collect, attempt to collect, protect or enforce the Collateral,
which the Company agrees and undertakes to do at the Company's expense; provided
that the Collateral Agent and the Trustees shall cooperate with the Company and
take all such action as the Company may reasonably request, to permit the
Company to collect, protect or enforce the Collateral. All reasonable expenses
(including, without limitation, attorneys' fees and legal expenses) actually
incurred or paid by the Collateral Agent and the Trustees in connection with or
incident to any such collection or attempt to collect, protect or enforce the
Collateral shall be borne by the Company or reimbursed by the Company to the
Collateral Agent or the applicable Trustee upon demand.


                                       12
<PAGE>   13
              (h) At the Collateral Agent's or the applicable Trustee's option,
exercisable upon and during the continuance of any Event of Default, either the
Collateral Agent or the Senior Note Trustee (or the Convertible Note Trustee if
the Senior Notes are no longer outstanding and the Senior Note Indenture has
been satisfied and discharged) may notify WTC or other obligors or issuers that
any and all payments and distributions to be made on the WTC Capital Stock or
the Intercompany Notes shall be made directly to the Collateral Agent or the
applicable Trustee, until WTC or other obligors or issuers is notified in
writing by the applicable Trustee to discontinue making such payments to it; and
WTC and such obligors and issuers shall not be required to see to the
application of said proceeds by the Trustees or the Collateral Agent. All such
payments shall be deposited by such Trustee or the Collateral Agent into the
Company Senior Note Escrow Account (or the Company Convertible Note Escrow
Account if the Company Senior Note Escrow Account Agreement has been terminated)
and held as additional Collateral for the Obligations. If at any time the
Collateral agent or a Trustee shall have notified WTC or other obligor or issuer
to make all payments directly to the Company and if at any time thereafter all
Events of Default shall have been cured or waived in accordance with the terms
of the Senior Note Indenture (or the Convertible Note Indenture if the Senior
Notes are no longer outstanding and the Senior Note Indenture has been satisfied
and discharged), the Collateral Agent or such Trustee shall notify WTC or the
other obligors or issuers to make all such payments directly to the Company or
as the Company may otherwise direct.

         SECTION 8. POWER OF ATTORNEY. In addition to all of the powers granted
to the Senior Note Trustee pursuant to Article VI of the Senior Note Indenture
and the Convertible Note Trustee pursuant to Article VI of the Convertible Note
Indentures, the Company hereby appoints and constitutes the Collateral Agent and
the Trustees, whether acting separately or jointly, as the Company's
attorney-in-fact to exercise all of the following powers upon and at any time
after the occurrence and during the continuance of an Event of Default: (i)
collection of proceeds of any Collateral; (ii) conveyance of any item of
Collateral to any purchaser thereof; (iii) giving of any notices or recording of
the security interest and the Liens under Section 6(d) hereof; (iv) making of
any payments or taking any acts under Section 9 hereof and (v) paying or
discharging taxes or Liens levied or placed upon the Collateral, the legality or
validity thereof and the amounts necessary to discharge the same to be
determined by the Collateral Agent in its sole discretion, and such payments
made by the Collateral Agent to become the Obligations of the Company to the
Collateral Agent, due and payable immediately upon demand. The Collateral
Agent's authority hereunder shall include, without limitation, the authority to
endorse and negotiate any checks or instruments representing proceeds of
Collateral in the name of the Company, to execute and give


                                       13
<PAGE>   14
receipt for any certificate of ownership or any document constituting
Collateral, to transfer title to any item of Collateral, to sign the Company's
name on all financing statements (to the extent permitted by applicable law) or
any documents deemed necessary or appropriate by the Collateral Agent to
preserve, protect or perfect the Liens in the Collateral and to file the same,
to prepare, file and sign the Company's name on any notice of Lien, and to
prepare, file and sign the Company's name on a proof of claim in bankruptcy or
similar document against any customer of, or person obligated upon any
Collateral to, the Company, and to take any other actions arising from or
incident to the powers granted to the Collateral Agent in this Security
Agreement. This power of attorney is coupled with an interest in the Trustees
and in the Collateral Agent as agent on behalf of the Trustees and is
irrevocable by the Company.

         SECTION 9. COLLATERAL AGENT OR TRUSTEES MAY PERFORM. If the Company
fails to perform any covenant or agreement contained herein, the Collateral
Agent or either Trustee may, but shall not be obligated to, itself perform, or
cause performance of, such covenant or agreement, and the reasonable expenses of
the Collateral Agent or the Trustees incurred in connection therewith shall be
payable by the Company under Section 16(p) hereof.

         SECTION 10. NO ASSUMPTION OF DUTIES; REASONABLE CARE. The rights and
powers granted to the Collateral Agent or the Trustees hereunder are being
granted in order to preserve and protect the Collateral Agent's Liens and
security interest in and to the Collateral granted hereby and shall not be
interpreted to, and shall not, impose any duties on the Collateral Agent or the
Trustees in connection therewith. Each of the Collateral Agent and the Trustees
shall be deemed to have exercised reasonable care in the custody and
preservation of the Collateral in its possession if the Collateral is accorded
treatment substantially equal to that which the Collateral Agent or such Trustee
accords similar property in similar situations, it being understood that the
Collateral Agent and the Trustees shall not have any responsibility for (i)
ascertaining or taking action with respect to calls, conversions, exchanges,
maturities, tenders or other matters relative to any Collateral, whether or not
the Collateral Agent or either Trustee has or is deemed to have knowledge of
such matters, (ii) taking any necessary steps to preserve rights against any
parties with respect to any Collateral, or (iii) inquiring into or verifying
that the Company has complied or will comply with its duty to furnish additional
items of Collateral to the Collateral Agent and/or the Trustees pursuant to
Section 6(d) hereof. Absent knowledge to the contrary, the Collateral Agent and
the Trustees may assume that the items of Collateral actually delivered to it
are all items required to be so delivered and may assume that no other such
items need be so delivered.


                                       14
<PAGE>   15
         SECTION 11. SUBSEQUENT CHANGES AFFECTING COLLATERAL. The Company
represents to the Collateral Agent, the Senior Note Trustee and the Holders of
the Senior Notes and the Convertible Note Trustee and the Holders of the
Convertible Notes, that the Company has made its own arrangements for keeping
informed of changes or potential changes affecting the Collateral (including,
but not limited to, rights to convert, rights to subscribe, payment of
dividends, payments of interest and/or principal, reorganization or other
exchanges, tender offers and voting rights), and the Company agrees that the
Collateral Agent, the Senior Note Trustee and the Holders of the Senior Notes,
and the Convertible Note Trustee and the Holders of the Convertible Notes shall
have no responsibility or liability for informing the Company of any such
changes or potential changes or for taking any action or omitting to take any
action with respect thereof. Except as not prohibited by the Senior Note
Indenture (or the Convertible Note Indenture if the Senior Notes are no longer
outstanding and the Senior Note Indenture has been satisfied and discharged),
the Company covenants that it will not, without the prior written consent of the
applicable Trustee, vote to enable, or take any other action to permit, any
Issuer to issue any Capital Stock or other securities or to sell or otherwise
dispose of, or grant any option with respect to, any of the Collateral or create
or permit to exist any Lien upon or with respect to any of the Collateral,
except for, Permitted Liens and the Liens granted under this Security Agreement
and the other Senior Note Collateral Documents. The Company will defend the
right, title and interest of the Collateral Agent, the Senior Note Trustee and
the Holders of the Senior Notes and the Convertible Note Trustee and the Holders
of the Convertible Notes in and to the Collateral against the claims and demands
of all persons.

         SECTION 12. REMEDIES UPON AN EVENT OF DEFAULT.

              (a)  Upon the occurrence and during the continuance of an Event of
Default, the Collateral Agent may, subject to the provisions of the Senior Note
Indenture (or of the Convertible Note Indenture if the Senior Notes are no
longer outstanding and the Senior Note Indenture has been satisfied and
discharged), this Security Agreement, the Collateral Agent's and the Trustees'
compliance with any requirements of law (including, without limitations, the
applicable Uniform Commercial Code and the Personal Property Security Act
(Ontario)) applicable to the action to be taken, without notice to or demand
upon the Company except as required by the Senior Note Indenture (or the
Convertible Note Indenture if the Senior Notes are no longer outstanding and the
Senior Note Indenture has been satisfied and discharged), this Agreement or
applicable law, do any one or more of the following:

                   (i)  exercise any or all of the rights and remedies provided
for by the applicable Uniform Commercial Code


                                       15
<PAGE>   16
and the Personal Property Security Act (Ontario), specifically including,
without limitation, the right to recover the reasonable fees and expenses
incurred by the Collateral Agent or the Trustees in the enforcement of this
Security Agreement or in connection with the Company's redemption of the
Collateral, including reasonable fees, expenses and disbursements of attorneys,
paralegals and agents;

                   (ii)   at its option, transfer or register, and the Company
shall register or cause to be registered upon request therefor by the Collateral
Agent or the Trustees, the Collateral or any part thereof on the books of the
Restricted Subsidiaries to which an intercompany loan evidenced by an
Intercompany Note has been made, the Issuers, or the Persons in whom Qualified
Investments are made into the name of the Collateral Agent or the Collateral
Agent's nominee(s);

                   (iii)  personally, or by agents or attorneys, immediately
retake possession of the Collateral, or any part thereof, from the Company or
any other Person who then has possession of any part thereof with or without
notice or process of law, and for that purpose may enter upon the Company's
premises where any of the Collateral is located and remove the same and use in
connection with such removal any and all services, supplies, aids and other
facilities of the Company;

                   (iv)   sell, assign or otherwise liquidate, or direct the
Company to sell, assign or otherwise liquidate, any or all of the Collateral or
any part thereof, and take possession of the proceeds of any such sale or
liquidation;

                   (v)    require the Company to assemble the Collateral or any
part thereof and make it available at one or more places as the Collateral Agent
or the Trustees may designate and to deliver possession of the Collateral or any
part thereof to the Collateral Agent or the Trustees;

                   (vi)   use, in connection with any assembly, use or
disposition of the Collateral, any intellectual property, intangibles or other
technical knowledge or process used or utilized from time to time by the
Company;

                   (vii)  sell or cause the same to be sold at any broker's
board or at public or private sale, in one or more sales or lots, at such price
or prices as the Collateral Agent may deem best, for cash or on credit or for
future delivery, without assumption of any credit; and the purchaser of any or
all Collateral so sold shall thereafter hold the same absolutely, free from any
claim, encumbrance or right of any kind whatsoever;

                   (viii) enforce one or more remedies hereunder, successively
or concurrently, and such action shall not operate


                                       16
<PAGE>   17
to estop or prevent the Collateral Agent from pursuing any other or further
remedy which it may have, and any repossession or retaking or sale of the
Collateral pursuant to the terms hereof shall not operate to release the Company
until full and final payment of any deficiency has been made in cash;

                   (ix)  in connection with any public or private sale under the
applicable Uniform Commercial Code, the Personal Property Security Act (Ontario)
or other applicable legislation, the Collateral Agent shall give the Company at
least fifteen (15) Business Days' prior written notice of the time and place of
any public sale of its Collateral or of the time after which any private sale or
other intended disposition thereof may be made, which shall be deemed to be
reasonable notice of such sale or other disposition. Such notice may be given to
the Company in accordance with the provisions of Section 16(a) hereof;

                   (x)   proceed by an action or actions at law or in equity to
recover the Obligations or to foreclose this Security Agreement and sell the
Collateral, or any portion thereof, pursuant to a judgment or decree of a court
or courts of competent jurisdiction;

                   (xi)  exercise any other rights and remedies provided by
applicable law and the other Senior Note Collateral Documents; and

                   (xii) if the Collateral Agent recovers possession of all or
any part of the Collateral pursuant to a writ of possession or other judicial
process, whether prejudgment or otherwise, the Collateral Agent may thereafter
retain, sell or otherwise dispose of such Collateral in accordance with this
Security Agreement or the applicable Uniform Commercial Code, the Personal
Property Security Act (Ontario) or other applicable legislation and following
such retention, sale or other disposition, the Collateral Agent may voluntarily
dismiss without prejudice the judicial action in which such writ of possession
or other judicial process was issued. The Company hereby consents to the
voluntary dismissal by the Collateral Agent of such judicial action, and the
Company further consents to the exoneration of any bond that the Collateral
Agent files in such action.

              (b)  If the Collateral Agent shall determine, or shall be directed
by the Senior Note Trustee (or the Convertible Note Trustee if the Senior Notes
are no longer outstanding and the Senior Note Indenture has been satisfied and
discharged), to exercise its right to sell any or all of the WTC Capital Stock
or the Intercompany Notes constituting Collateral pursuant to Section 12(a)
above, and if in the opinion of counsel for the Collateral Agent it is
necessary, or if in the opinion of the Collateral Agent or such Trustee it is
advisable, after such


                                       17
<PAGE>   18
consultation with investment bank(s), broker-dealer(s) or other experts selected
by them, as the Collateral Agent or such Trustee deems advisable or appropriate,
to have the WTC Capital Stock or Intercompany Notes constituting Collateral or
that portion thereof to be sold, registered under the provisions of the
Securities Act of 1933, as amended (the "Securities Act"), the Company will (i)
use its best efforts to cause WTC or other issuer or obligor to execute and
deliver, and to cause such Person's directors and officers to execute and
deliver, all at the Company's own expense, all such instruments and documents,
and to do or cause to be done all such other acts and things as may be necessary
or, in the opinion of the Collateral Agent or such Trustee, after such
consultation with investment bank(s), broker-dealer(s) or other experts selected
by them, as the Collateral Agent or such Trustee deems advisable or appropriate,
advisable to register such, WTC Capital Stock or Intercompany Notes under the
provisions of the Securities Act, (ii) use its best efforts to cause the
registration statement relating thereto to become effective and to remain
effective for a period of 180 days from the date of the first public offering of
such WTC Capital Stock or Intercompany Notes, or that portion thereof, to be
sold and (iii) make all amendments thereto and/or to the related prospectus that
are necessary or, in the opinion of the Collateral Agent or such Trustee,
advisable, all in conformity with the requirements of the Securities Act and the
rules and regulations of the Securities and Exchange Commission applicable
thereto. The Company agrees to use its best efforts to cause WTC or other issuer
or obligor to comply with the provisions of the securities or "Blue Sky" laws of
any jurisdiction that the Collateral Agent or the Senior Note Trustee or the
Convertible Note Trustee if the Senior Notes are no longer outstanding and the
Senior Note Indenture has been satisfied and discharged shall designate for the
sale of WTC Capital Stock or Intercompany Notes and to make available to the
security holders of WTC or other obligor or issuer as soon as practicable, an
earnings statement (which need not be audited) that will satisfy the provisions
of Section 11(a) of the Securities Act. The Company will cause WTC or other
obligor or issuer to furnish to the Collateral Agent and the Trustees such
number of copies as the Trustee may reasonably request of each preliminary
prospectus and prospectus, to notify promptly the Collateral Agent and the
Trustees of the happening of any event as a result of which any then effective
prospectus includes an untrue statement of any material fact or omits to state a
material fact required to be stated therein or necessary to make the statements
therein not misleading in the light of then existing circumstances and cause the
Collateral Agent and the Trustees to be furnished with such number of copies as
the Collateral Agent and the Trustees may request of such supplement to or
amendment of such prospectus as is necessary to eliminate such untrue statement
or supply such omission. The Company will cause WTC or such other issuer or
obligor, as the case may be, to the extent permitted by law, to indemnify,
defend and hold


                                       18
<PAGE>   19
harmless the Collateral Agent, the Senior Note Trustee and the Holders of the
Senior Notes, and the Convertible Note Trustee and the Holders of the
Convertible Notes from and against all losses, liabilities, expenses or claims
(including reasonable costs of investigation) that the Collateral Agent, the
Senior Note Trustee or the Holders of the Senior Notes or the Convertible Note
Trustee or the Holders of the Convertible Notes may incur under the Securities
Act or otherwise, insofar as such losses, liabilities, expenses or claims arise
out of or are based upon any alleged untrue statement of a material fact
contained in such registration statement (or any amendment thereto) or in any
preliminary prospectus or prospectus (or any amendment or supplement thereto),
or arise out of or are based upon any alleged omission to state a material fact
required to be stated therein or necessary to make the statements therein not
misleading, except to the extent that any such losses, liabilities, expenses or
claims arise solely out of or are based solely upon any such alleged untrue
statement made or such alleged omission to state a material fact included or
excluded on the written direction of the Collateral Agent or a Trustee. The
Company will bear, or will cause WTC or other issuer or obligor to bear, all
costs and expenses of carrying out its or their obligations hereunder. The
provisions of this Section 12(b) shall in now way impose upon either Trustee or
the Collateral Agent any duty to execute any registration statement under the
Securities Act with respect to any WTC Capital Stock or Intercompany Notes.

              (c)  In view of the fact that federal, state and foreign
securities laws may impose certain restrictions on the method by which a sale of
the Collateral may be effected after an Event of Default, the Company agrees
that upon the occurrence and during the continuance of an Event of Default, the
Collateral Agent may, from time to time, attempt to sell all or any part of the
Collateral by means of a private placement, restricting the prospective
purchasers to those who will represent and agree that they are purchasing for
investment only and not for distribution. In so doing, the Collateral Agent may
solicit, or may cause an investment manager to solicit, offers to buy the
Collateral, or any part of it, for cash, from a limited number of investors who
might be interested in purchasing the Collateral. The Company acknowledges and
agrees that any such private sale may result in prices and terms less favorable
than if such sale were a public sale and, notwithstanding such circumstances,
agrees that any such private sale shall be deemed to have been made in a
commercially reasonable manner. The Collateral Agent shall be under no
obligation to delay a sale of any of the Collateral for the period of time
necessary to permit the Company to cause WTC or other issuer or obligor to
register such securities for public sale under the Securities Act, or under
applicable state or foreign securities laws, even if the Company could cause WTC
or other issuer or obligor to do so.


                                       19
<PAGE>   20
              (d)    The Company further agrees to use its best efforts to do or
cause to be done all such other acts as may be necessary to make such sale or
sales of all or any portion of the Collateral pursuant to this Section 12 valid
and binding and in compliance with any and all other applicable requirements of
applicable law. The Company further agrees that a breach of any of the covenants
contained in this Section 12 will cause irreparable injury to the Collateral
Agent, the Senior Note Trustee, the Holders of the Senior Notes, the Convertible
Note Trustee or the Holders of the Convertible Notes, that the Collateral Agent,
the Senior Note Trustee, the Holders of the Senior Notes, the Convertible Note
Trustee or the Holders of the Convertible Notes have no adequate remedy at law
in respect of such breach and, as a consequence, that each and every covenant
contained in this Section 12 shall be specifically enforceable against the
Company, and the Company hereby waives and agrees not to assert any defenses
against an action for specific performance of such covenants except for a
defense that no Event of Default has occurred and is continuing.

              (e)    Any cash held by the Collateral Agent as Collateral and all
cash proceeds received by the Collateral Agent in respect of any sale of,
collection from, or other realization upon all or any part of the Collateral
shall be applied by the Collateral Agent:

                     First, to the payment of the costs and expenses of such
              sale, including, without limitation, reasonable expenses of the
              Collateral Agent and its agents including the fees and expenses of
              its counsel, and all expenses, liabilities and advances made or
              incurred by the Collateral Agent in connection therewith or
              pursuant to Section 16(p) hereof;

                     Next, to the Senior Note Trustee, for the payment in full
              of all amounts due under Section 7.7 of the Senior Note Indenture;

                     Next, to the Senior Note Trustee, for distribution to the
              Holders of the Senior Notes, for the payment in full of the
              remaining Senior Note Obligations;

                     Next, to the Convertible Note Trustee, for the payment in
              full of all amounts due under Section 7.7 of the Convertible Note
              Indenture;

                     Next, to the Convertible Note Trustee, for the distribution
              to the Holders of the Convertible Notes for payment in full of the
              remaining Convertible Note Obligations; and


                                       20
<PAGE>   21
                     Finally, after payment in full of all of the Obligations,
              to the Company, or its successors or assigns, or to whomsoever may
              be lawfully entitled to receive the same as a court of competent
              jurisdiction may direct.

              (f)  If any sale or other disposition of Collateral by the
Collateral Agent or any other action of the Collateral Agent or the Trustees
hereunder results in reduction of the Obligations, such action will not release
the Company from its liability for any unpaid Obligations, including costs,
charges and expenses incurred in the liquidation of Collateral, together with
interest thereon, and the same shall be immediately due and payable to the
Collateral Agent, the Senior Note Trustee and the Holders of the Senior Notes as
provided for in the Senior Note Indenture, or, if applicable, the Convertible
Note Trustee and the Holders of the Convertible Notes as provided for in the
Convertible Note Indenture.

              (g)  The Collateral Agent may enforce its rights hereunder without
prior judicial process or judicial hearing, and to the extent permitted by law
the Company expressly waives any and all legal rights which might otherwise
require the Collateral Agent to enforce its rights by judicial process.

              (h)  The existence and/or exercise of any or all of the rights and
remedies given to the Collateral Agent and/or the Trustees under this Section 12
shall be subject in all cases to compliance with any mandatory requirements of
applicable law, particularly the laws of jurisdictions other than the Union
States.

         SECTION 13. IRREVOCABLE AUTHORIZATION AND INSTRUCTIONS TO WTC OR
APPLICABLE ISSUER. The Company hereby authorizes and instructs WTC or other
applicable issuer or obligor to comply with any instructions received by WTC or
other issuer or obligor from the Collateral Agent or the Senior Note Trustee (or
the Convertible Note Trustee if the Senior Notes are no longer outstanding and
the Senior Note Indenture has been satisfied and discharged) that (i) states
that an Event of Default has occurred and (ii) is otherwise in accordance with
the terms of this Security Agreement, without any other or further instructions
from the Company, and the Company agrees that WTC and the other applicable
issuers and obligors shall be fully protected in so complying.

         SECTION 14. SECURITY INTEREST ABSOLUTE. All rights of the Collateral
Agent, the Senior Note Trustee and the Holders of the Senior Notes, and the
Convertible Note Trustee and the Holders of the Convertible Notes and the Liens
or security interests hereunder, and all obligations of the Company hereunder,
shall be absolute and unconditional irrespective of:


                                       21
<PAGE>   22
              (a)  any lack of validity or enforceability of the Senior Note
Indenture, any Senior Note Collateral Document, any Senior Note Guarantee, the
Convertible Note Indenture, any Convertible Note Collateral Document, any
Convertible Note Guarantee or any other agreement or instrument relating
thereto;

              (b)  any change in the time, manner or place of payment of, or in
any other term of, all or any of the Obligations, or any other amendment or
waiver of or any consent to any departure from the Senior Note Indenture or the
Senior Note Collateral Documents or from the Convertible Note Indenture or the
Convertible Note Collateral Documents;

              (c)  any exchange, surrender, release or non-perfection of any
Liens on any other collateral, or any release or amendment or waiver of or
consent to departure from any Senior Note Guarantee, any Convertible Note
Guarantee or other guarantee, for all or any of the Obligations; or

              (d)  any other circumstance which might otherwise constitute a
defense available to, or a discharge of, the Company in respect of the
Obligations or of this Security Agreement.

         SECTION 15. WAIVERS.

              (a)  Except as may be required under the provisions of the Senior
Note Indenture (or of the convertible Note Indenture if the Senior Notes are no
longer outstanding and the Senior Note Indenture has been satisfied and
discharged), and to the fullest extent permitted under applicable law, neither
the Collateral Agent nor the Senior Note Trustee (or the Convertible Note
Trustee if the Senior Notes are no longer outstanding and the Senior Note
Indenture has been satisfied and discharged) shall be under any duty whatsoever
to make or give any presentment, notice of dishonor, protest, demand for
performance, notice of non-performance, notice of intent to accelerate, notice
of acceleration, or other notice or demand in connection with any Collateral or
the Obligations, or to take any steps reasonably necessary to preserve any
rights against any Obligor or other Person. The Company waives to the fullest
extent permitted under applicable law any right of marshalling in respect of any
and all Collateral, and waives to the fullest extent permitted lender applicable
law any right to require the Collateral Agent or the applicable Trustee to
proceed against any Obligor or other Person, exhaust any Collateral or enforce
any other remedy which the Collateral Agent or the applicable Trustee now has or
may hereafter have against any Obligor or other Person.

              (b)  The Company waives to the fullest extent permitted under
applicable law (i) any and all notices of acceptance, creation, modification,
rearrangement, renewal or extension for any period of any instrument executed by
any Obligor in


                                       22
<PAGE>   23
connection with the Obligations and (ii) any defense of any Obligor by reason of
disability, lack of authorization, cessation of the liability of any Obligor or
for any other reason. The Company authorizes the Collateral Agent, to the
fullest extent permitted under applicable law without notice or demand and
without any reservation of rights against the Company and without affecting the
Company's liability hereunder or on the Obligations, from time to time to (w)
take and hold other Property, other than the collateral, as security for the
Obligations, and exchange, enforce, waive and release any or all of the
collateral, (x) after the occurrence and during the continuance of an Event of
Default and the acceleration of the Senior Notes, apply the Collateral in the
manner permitted by this Security Agreement or the Senior Note Indenture, (y)
after the occurrence and during the continuance of an Event of Default and the
acceleration of the Convertible Notes, if the Senior notes are no longer
outstanding and the Senior Note Indenture has been satisfied and discharged,
apply the Collateral in the manner permitted by this Security Agreement or the
Convertible Note Indenture and (z) after the occurrence and during the
continuance of an Event of Default renew, extend for any period, accelerate,
amend or modify, supplement, enforce, compromise, settle, waive or release the
obligations of any obligor on, or any instrument or agreement of such other
Person with respect to any or all of, the Collateral.

         SECTION 16. MISCELLANEOUS PROVISIONS.

              (a)  Notices. All notices, approvals, consents or other
communications required or desired to be given hereunder shall be in the form
and manner, and delivered to each of the Company at its address as set forth in
Section 13.2 of the Senior Note Indenture and Section 15.2 of the Convertible
Note Indenture and the Senior Note Trustee at its address, as set forth in
Section 13.2 of the Senior Note Indenture, and Section 15.2 of the Convertible
Note Indenture and to the Collateral Agent at The Bank of New York, 101 Barclay
Street, Floor 21 West, New York, New York 10296.

              (b)  Sales of Collateral. No sales of Collateral may be made in
contravention of the terms of the Senior Note Indenture or the Convertible Note
Indenture and the cash proceeds of the sale of any Collateral shall be promptly
and without commingling remitted to the Collateral Agent or the Trustee for
deposit in the Company Senior Note Escrow Account or to the Collateral Agent or
the Convertible Note Trustee for deposit in the Company Convertible Note Escrow
Account if the Company Senior Note Escrow Account Agreement has been terminated.

              (c)  No Adverse Interpretation of Other Agreements. This Security
Agreement may not be used to interpret another pledge, security or debt
agreement of the Company or any


                                       23
<PAGE>   24
Subsidiary of the Company. No such pledge, security or debt agreement may be
used to interpret this Security Agreement.

              (d)  Severability. The provisions of this Security Agreement are
severable, and if any clause or provision shall be held invalid, illegal or
unenforceable in whole or in part in any jurisdiction, then such invalidity or
unenforceability shall affect in that jurisdiction only such clause or
provision, or part thereof, and shall not in any manner affect such clause or
provision in any other jurisdiction or any other clause or provision of this
Security Agreement in any jurisdiction.

              (e)  Headings. The headings in this Security Agreement have been
inserted for convenience of reference only, are not to be considered a part
hereof and shall in no way modify or restrict any of the terms or provisions
hereof.

              (f)  Counterpart Originals. This Security Agreement may be signed
in two or more counterparts, each of which shall be deemed an original, but all
of which shall together constitute one and the same agreement.

              (g)  Benefits of Security Agreement. Nothing in this Security
Agreement, express or implied, shall give to any person, other than the parties
hereto and their successors hereunder and the Holders of the Senior Notes and
the Senior Note Guarantors, and the Holders of the Convertible Notes and the
Convertible Note Guarantors any benefit or any legal or equitable right, remedy
or claim under this Security Agreement.

              (h)  Amendments, Waivers and Consents. Any amendment or waiver of
any provision of this Security Agreement and any consent to any departure by the
Company from any provision of this Security Agreement shall be effective only if
made or given in compliance with all of the terms and provisions of the Senior
Note Indenture and the Convertible Note Indenture and neither the Collateral
Agent nor the Senior Note Trustee or any Holder of any Senior Note or the
Convertible Note Trustee or any Holder of Convertible Notes shall be deemed, by
any act, delay, indulgence, omission or otherwise, to have waived any right or
remedy hereunder or to have acquiesced in any Default or Event of Default or in
any breach of any of the terms and conditions hereof. Failure of the Collateral
Agent or the Trustees to exercise, or delay in exercising, any right, power or
privilege hereunder shall not operate as a waiver thereof. No single or partial
exercise of any right, power or privilege hereunder shall preclude any other or
further exercise thereof or the exercise of any other right, power or privilege.
A waiver by the Collateral Agent, the Senior Note Trustee or any Holder of any
Senior Note or the Convertible Note Trustee or any Holder of any Convertible
Note of any right or remedy hereunder on any one occasion shall not be construed
as a bar to any right or remedy that the


                                       24
<PAGE>   25
Collateral Agent, such Trustee or any such Holder would otherwise have on any
future occasion. The right and remedies herein provided are cumulative, may be
exercised singly or concurrently and are not exclusive of any rights or remedies
provided by law.

              (i)  Interpretation of Security Agreement. All terms not defined
herein or in the Indenture shall have the meaning set forth in the applicable
Uniform Commercial Code of the State of New York, except where the context
otherwise requires. To the extent a term or provision of this Security Agreement
conflicts with the Senior Note Indenture, the Senior Note Indenture shall
control with respect to the subject matter of such term or provision. Acceptance
of or acquiescence in a course of performance rendered under this Security
Agreement shall not be relevant in determining the meaning of this Security
Agreement even though the accepting or acquiescing party had knowledge of the
nature of the performance and opportunity for objection.

              (j)  Continuing Security Interest; Transfer of Notes. This
Security Agreement shall create a continuing Lien and security interest in the
Collateral and shall (i) unless otherwise provided in the Senior Note Indenture
or the Convertible Note Indenture if the Senior Notes are no longer outstanding
and the Senior Note Indenture has been satisfied and discharged or this Security
Agreement, remain in full force and effect until payment in full of (A) the
Senior Notes under the terms of the Senior Note Indenture, (B) all Obligations
then due and owing under the Senior Note Indenture, the Senior Note Guarantees
and the Senior Note Collateral Documents, (C) the Convertible Notes under the
terms of the Convertible Note Indenture and (D) all Obligations then due and
owing under the Convertible Note Indenture, the Convertible Note Guarantees and
the Convertible Note Collateral Documents; provided, however, that after receipt
from the Company by the Collateral Agent of a request for a release of any
Collateral permitted under the Senior Note Indenture and the Convertible Note
Indenture upon the sale, transfer, assignment, exchange or other disposition of
such Collateral not prohibited by the Senior Note Indenture and the Convertible
Note Indenture and upon receipt by the Collateral Agent of all proceeds of such
sale, transfer, assignment, exchange or other disposition required to be
remitted to the Collateral Agent or the Senior Note Trustee (or the Convertible
Note Trustee if the Senior Notes are no longer outstanding and the Senior Note
Indenture has been satisfied and discharged), or the Collateral constituting the
proceeds of such sale, transfer, assignment, exchange or other disposition being
made subject to a Lien and security interest in favor of the Collateral Agent
for the benefit of the Senior Note Trustee and the equal and ratable benefit of
the Holders of the Senior Notes and for the benefit of the Convertible Note
Trustee and the equal and ratable benefit of the Holders of the Convertible
Notes, which Lien has the same priority as had the Lien on the Collateral being
sold, assigned


                                       25
<PAGE>   26
or otherwise disposed of, such Collateral shall be released from the Liens and
security interest created hereunder and no longer constitute Collateral. Upon
the payment in full of (A) the Senior Notes under the terms of the Senior Note
Indenture and (B) all Obligations then due and owing under the Senior Note
Indenture, the Senior Note Guarantees and the Senior Note Collateral Documents,
(C) the Convertible Notes under the terms of the Convertible Note Indenture and
(D) all Obligations then due and owing under the Convertible Note Indenture, the
Convertible Note Guarantees and the Convertible Note Collateral Documents, the
Company shall be entitled to the return, upon its request and at its expense, of
such of the Collateral pledged by it as shall not have been sold or otherwise
applied pursuant to the terms hereof. This Security Agreement shall be binding
upon the Company, its successors and assigns, and inure, together with the
rights and remedies of the Trustees hereunder, to the benefit of the Collateral
Agent, the Senior Note Trustee and the Holders of the Senior Notes, and the
Convertible Note Trustee and the Holders of the Convertible Notes and their
respective successors, transferees and assigns.

              (k)  Reinstatement. This Security Agreement shall continue to be
effective or be reinstated, as the case may be, if at any time any amount
received by the Collateral Agent, the Senior Note Trustee or any Holder of a
Senior Note or the Convertible Note Trustee or any Holder or a Convertible Note
in respect of the Obligations is rescinded or must otherwise be restored or
returned by the Collateral Agent, the Senior Note Trustee or any Holder of a
Senior Note or the Convertible Note Trustee or any Holder of a Convertible Note
upon the insolvency, bankruptcy, dissolution, liquidation or reorganization of
the Company or upon the appointment of any receiver, intervenor, conservator,
trustee or similar official for the Company or upon the appointment of any
receiver, intervenor, conservator, trustee or similar official for the Company
or any substantial part of their assets, or otherwise, all as though such
payments had not been made.

              (l)  Survival of Provisions. All representations, warranties and
covenants of the Company contained herein shall survive the execution and
delivery of this Security Agreement, and shall terminate only upon the full and
final payment and performance by the Company of the Obligations.

              (m)  Authority of the Collateral Agent and the Trustees. Both the
Collateral Agent and the Trustees shall have and be entitled to exercise all
powers hereunder that are specifically granted to the Collateral Agent and the
Trustees by the terms hereof, together with such powers as are reasonably
incident thereto. The Collateral Agent and the Trustees may perform any of their
duties hereunder or in connection with the Collateral by or through agents or
employees and shall be


                                       26
<PAGE>   27
entitled to retain counsel and to act in reliance upon the advice of counsel
concerning all such matters. None of the Collateral Agent, any director,
officer, employee, attorney or agent of the Collateral Agent, the Senior Note
Trustee, any director, officer, employee, attorney or agent of the Senior Note
Trustee nor the Holders of the Senior Notes, the Convertible Note Trustee, any
director, officer, employee, attorney or agent of the Convertible Note Trustee
and the Holders of the Convertible Notes shall be liable to the Company for any
action taken or omitted to be taken by it or them hereunder, except for its or
their own negligence or willful misconduct, nor shall the Collateral Agent or
the Trustees be responsible for the validity, effectiveness or sufficiency
hereof or of any document or security furnished pursuant hereto. The Collateral
Agent, and its directors, officers, employees, attorneys or agents, and the
Senior Note Trustee and its directors, officers, employees, attorneys and agents
and the Convertible Note Trustee and its directors, officers, employees,
attorneys and agents shall be entitled to rely on any communication, instrument
or document believed by it or them to be genuine and correct and to have been
signed or sent by the proper person or persons. Neither the Collateral Agent nor
the Trustees shall be required to and shall not, expend or risk any of its own
funds or otherwise incur any financial liability in the performance of any of
its duties hereunder.

                   The Company acknowledges that the rights and responsibilities
of the Collateral Agent and the Trustees under this Security Agreement with
respect to any action taken by the Collateral Agent and the Trustees or the
exercise or non-exercise by the Collateral Agent and the Trustees of any option,
right, request, judgment or other right or remedy provided for herein or
resulting or arising out of this Security Agreement shall, as among the
Collateral Agent, the Senior Note Trustee, the Holders of the Senior Notes, the
Convertible Note Trustee and the Holders of Convertible Notes, be governed by
the Senior Note Indenture and the Convertible Note Indenture, as applicable, and
by such other agreements with respect thereto as may exist from time to time
among them, but, as among the Collateral Agent, the Trustees and the Company,
the Collateral Agent and the Trustees shall be conclusively presumed to be
acting as agent for the Holders of the Senior Notes or the Holders of the
Convertible Notes, as the case may be, with full and valid authority so to act
or refrain from acting, and the Company shall not be obligated or entitled to
make any inquiry respecting such authority.

                   In any case in which the Collateral Agent shall be required 
or permitted to make any determination as to the extent to which the security
interest or Liens under this Security Agreement secures any obligations, the
Collateral Agent is authorized, without any direction from, or requirement for
consent of or authorization by, the Senior Note Trustee (or the Convertible Note
Trustee if the Senior Notes are no longer


                                       27
<PAGE>   28
outstanding and the Senior Note Indenture has been satisfied and discharged), to
institute proceedings in a court of competent jurisdiction for the obtaining of
any authoritative determination of such matter. If the Collateral Agent
institutes any such proceeding, it shall give prompt written notice thereof to
the Trustees and shall afford each of them the opportunity to participate in
such proceeding.

              (n)  Limitation by Law. All rights, remedies and powers provided
herein may be exercised only to the extent that they will not render this
Security Agreement not entitled to be recorded, registered or filed under
provisions of any applicable law.

              (o)  Release; Termination of Security Agreement.

                   (i)   Subject to the provisions of Section 16(k) hereof, this
Security Agreement shall terminate upon payment in full of (A) the Senior Notes
under the terms of the Senior Note Indenture and (B) all Obligations then due
and owing under the Senior Note Indenture, the Senior Note Guarantees and the
Senior Note Collateral Documents, (C) the Convertible Notes under the terms of
the Convertible Note Indenture and (D) all Obligations then due and owing under
the Convertible Note Indenture, the Convertible Note Guarantees and the
Convertible Note Collateral Documents, except that the provisions of Section
16(p) hereof shall survive.

                   (ii)  The Company agrees that it will not sell or dispose of
any of the Collateral in violation of the Senior Note Indenture or the
Convertible Note Indenture; provided, however, that if the Company shall sell or
otherwise dispose of any of the Collateral in accordance with the terms of the
Senior Note Indenture and/or the Convertible Note Indenture, the Collateral
Agent shall, and the Trustees shall cause, at the request of the Company,
release or cause to be released the Collateral subject to such sale or
disposition free and clear of the Lien and security interest under this Security
Agreement.

                   (iii) Upon any termination of this Security Agreement or
release of any Collateral as permitted by the Senior Note Indenture (or the
Convertible Note Indenture if the Senior Notes are no longer outstanding and the
Senior Note Indenture has been satisfied and discharged), the Collateral Agent
and the Trustees will, at the expense of the Company, execute and deliver to the
Company such documents and take such other actions as the Company shall
reasonably request to evidence the termination of this Security Agreement or the
release of such Collateral, as the case may be. Any such action taken by the
Collateral Agent or the Trustees shall be without warranty by or recourse to the
Collateral Agent or the Trustees, except as to the absence of any prior
assignments by the Collateral Agent or the Trustees of its


                                       28
<PAGE>   29
interests in the Collateral, and shall be at the expense of the Company. The
Collateral Agent and the Trustees may conclusively rely on any certificate
delivered to it by the Company stating that the execution of such documents and
release of the Collateral is in accordance with and permitted by the terms of
this Security Agreement and the Senior Note Indenture (or the Convertible Note
Trustee if the Senior Notes are no longer outstanding and the Senior Note
Indenture has been satisfied and discharged).

              (p)  Payment of Fees and Expenses. The Company will upon demand
pay to the Collateral Agent and the Trustees, without duplication, the amount of
any and all fees and expenses, including, without duplication, the fees and
disbursements of its counsel and of any experts and agents, that the Collateral
Agent and the Trustees may incur in connection with (i) administration of this
Security Agreement, (ii) the custody, preservation, use or operation of, or the
sale of, collection from, or other realization upon, any of the Collateral,
(iii) the exercise or enforcement of any of the rights of the Collateral Agent
or the Trustees hereunder or (iv) the failure by the Company to perform or
observe any of the provisions hereof. The Company shall be liable for and
reimburse and indemnify both Trustees and the Collateral Agent and hold both
Trustees and the Collateral Agent harmless from and against any and all claims,
losses, liabilities, costs, damages or expenses (including reasonable attorneys'
fees and expenses) (collectively, "Losses") arising from or in connection with
or related to this Agreement or being a Trustee and Collateral Agent hereunder
(including but not limited to Losses incurred by such Trustee and Collateral
Agent in connection with its successful defense, in whole or in part, of any
claim of negligence or willful misconduct on its part, provided, however, that
nothing contained herein shall require Trustees and the Collateral Agent to be
indemnified for Losses caused by their respective negligence or willful
misconduct.

              (q)  Final Expression. This Security Agreement, together with the
Senior Note Indenture, the Convertible Note Indenture, and any other agreement
executed in connection herewith or therewith, is intended by the parties as a
final expression of this Security Agreement and is intended as a complete and
exclusive statement of the terms and conditions hereof.

              (r)  Company Remains Liable. Anything herein to the contrary
notwithstanding, (a) the Company shall remain liable under any contracts and
agreements included in the Collateral, to the extent set forth therein, to
perform all of its duties and obligations thereunder to the same extent as if
this Security Agreement had not been executed, (b) the exercise by the
Collateral Agent or the Trustees of any of the rights hereunder shall not
release the Company from any of its duties or


                                       29
<PAGE>   30
obligations under the contracts and agreements included in the Collateral and
(c) the Collateral Agent and the Trustees shall not have any obligation or
liability under any contracts and agreements included in the Collateral by
reason of this Security Agreement, nor shall the Collateral Agent or the
Trustees be obligated to perform any of the obligations or duties of the Company
thereunder or to take any action to collect or enforce any claim for payment
assigned hereunder.

              (s)  Indentures. This Security Agreement is subject to the terms,
conditions and provisions of the Senior Note Indenture or the Convertible Note
Indenture if the Senior Notes are no longer outstanding and the Senior Note
Indenture has been satisfied and discharged. Where there is a conflict between
the provisions of this Security Agreement and the Senior Note Indenture, the
provisions of the Senior Note Indenture shall prevail, and if the Senior Note
Indenture has been satisfied and discharged, where there is a conflict between
the provisions of this Security Agreement and the Convertible Note Indenture,
the provisions of the Convertible Note Indenture shall prevail.

              (t)  Rights of Holders. No Holder of a Senior Note or of a
Convertible Note shall have any independent rights hereunder other than those
rights granted to individual Holders pursuant to Section 6.7 of the Senior Note
Indenture or Section 6.7 of the Convertible Note Indenture, as the case may be;
provided that nothing in this subsection (t) shall limit any rights granted to
the Senior Note Trustee under the Senior Notes, the Senior Note Indenture or the
Senior Note Collateral Documents or the Convertible Note Trustee under the
Convertible Notes, the Convertible Note Indenture or the Convertible Note
Collateral Documents.

              (u)  No Personal Liability of Directors, Officers, Employees and
Stockholders. No past, present or future director, officer, employee,
incorporator or stockholder of the Company or of any subsidiary of the Company,
as such, shall have any liability for any obligations of the Company under this
Security Agreement or for any claim based on, in respect of, or by reason of,
such obligations or their creation.

              (v)  GOVERNING LAW; SUBMISSION TO JURISDICTION; WAIVER OF JURY
TRIAL; WAIVER OF DAMAGES.

                   (i)  THIS SECURITY AGREEMENT SHALL BE GOVERNED BY AND 
INTERPRETED UNDER THE LAWS OF THE STATE OF NEW YORK, AND ANY DISPUTE ARISING OUT
OF, CONNECTED WITH, RELATED TO, OR INCIDENTAL TO THE RELATIONSHIP ESTABLISHED 
BETWEEN THE COMPANY, THE COLLATERAL AGENT, THE SENIOR NOTE TRUSTEE AND THE
HOLDERS OF THE SENIOR NOTES AND THE CONVERTIBLE NOTE TRUSTEE AND THE HOLDERS OF
CONVERTIBLE NOTES IN CONNECTION WITH THIS SECURITY AGREEMENT, AND WHETHER
ARISING IN CONTRACT, TORT, EQUITY OR OTHERWISE, SHALL


                                       30
<PAGE>   31
BE RESOLVED IN ACCORDANCE WITH THE INTERNAL LAWS (AS OPPOSED TO THE CONFLICTS OF
LAWS PROVISIONS) AND DECISIONS OF THE STATE OF NEW YORK.

                   (ii)  THE COMPANY AGREES THAT THE COLLATERAL AGENT SHALL, IN
ITS CAPACITY AS COLLATERAL AGENT OR IN THE NAME AND ON BEHALF OF THE SENIOR NOTE
TRUSTEE AND ANY HOLDERS OF SENIOR NOTES, AND THE SENIOR NOTE TRUSTEE SHALL, IN
ITS CAPACITY AS SENIOR NOTE TRUSTEE OR IN THE NAME AND ON BEHALF OF ANY HOLDERS
OF SENIOR NOTES AND THE CONVERTIBLE NOTE TRUSTEE SHALL, IN ITS CAPACITY AS
CONVERTIBLE NOTE TRUSTEE OR IN THE NAME AND ON BEHALF OF ANY HOLDERS OF
CONVERTIBLE NOTES, HAVE THE RIGHT, TO THE EXTENT PERMITTED BY APPLICABLE LAW, TO
PROCEED AGAINST THE COMPANY OR ITS PROPERTY IN A COURT IN ANY LOCATION
REASONABLY SELECTED IN GOOD FAITH TO ENABLE THE COLLATERAL AGENT OR THE SENIOR
NOTE TRUSTEE TO REALIZE ON SUCH PROPERTY, OR TO ENFORCE A JUDGMENT OR OTHER
COURT ORDER ENTERED IN FAVOR OF THE COLLATERAL AGENT OR THE SENIOR NOTE TRUSTEE.
THE COMPANY AGREES THAT IT WILL NOT ASSERT ANY COUNTERCLAIMS, SETOFFS OR
CROSS-CLAIMS IN ANY PROCEEDING BROUGHT BY THE COLLATERAL AGENT OR THE TRUSTEES
TO REALIZE ON SUCH PROPERTY, OR TO ENFORCE A JUDGMENT OR OTHER COURT ORDER IN
FAVOR OF THE COLLATERAL AGENT OR EITHER TRUSTEE. THE COMPANY WAIVES ANY
OBJECTION THAT IT MAY HAVE TO THE LOCATION OF THE COURT IN WHICH THE COLLATERAL
AGENT OR SUCH TRUSTEE HAS COMMENCED A PROCEEDING DESCRIBED IN THIS PARAGRAPH
INCLUDING, WITHOUT LIMITATION, ANY OBJECTION TO THE LAYING OF VENUE OR BASED ON
THE GROUNDS OF FORUM NON CONVENIENS.

                   (iii) THE COMPANY, THE COLLATERAL AGENT AND THE TRUSTEES EACH
WAIVE ANY RIGHT TO HAVE A JURY PARTICIPATE IN RESOLVING ANY DISPUTE, WHETHER
SOUNDING IN CONTRACT, TORT, OR OTHERWISE ARISING OUT OF, CONNECTED WITH, RELATED
TO OR INCIDENTAL TO THE RELATIONSHIP ESTABLISHED BETWEEN THEM IN CONNECTION WITH
THIS SECURITY AGREEMENT. INSTEAD, ANY DISPUTES RESOLVED IN COURT WILL BE
RESOLVED IN A BENCH TRIAL WITHOUT A JURY.

                   (iv)  THE COMPANY AGREES THAT NONE OF THE COLLATERAL AGENT,
THE SENIOR NOTE TRUSTEE, ANY HOLDER OF A SENIOR NOTE, THE CONVERTIBLE NOTE AND
ANY HOLDER OF A CONVERTIBLE NOTE SHALL HAVE ANY LIABILITY TO THE COMPANY
(WHETHER SOUNDING IN TORT, CONTRACT OR OTHERWISE) FOR LOSSES SUFFERED BY THE
COMPANY IN CONNECTION WITH, ARISING OUT OF, OR IN ANY WAY RELATED TO, THE
TRANSACTIONS CONTEMPLATED AND THE RELATIONSHIP ESTABLISHED BY THIS SECURITY
AGREEMENT, OR ANY ACT, OMISSION OR EVENT OCCURRING IN CONNECTION THEREWITH,
UNLESS IT IS DETERMINED BY A FINAL AND NONAPPEALABLE JUDGMENT OF A COURT THAT IS
BINDING ON THE COLLATERAL AGENT, SUCH TRUSTEE OR SUCH NOTEHOLDER, AS THE CASE
MAY BE, THAT SUCH LOSSES WERE THE RESULT OF ACTS OR OMISSIONS ON THE PART OF THE
COLLATERAL AGENT, THE SENIOR NOTE TRUSTEE OR SUCH HOLDER OF A SENIOR NOTE OR THE
CONVERTIBLE NOTE TRUSTEE OR ANY


                                       31
<PAGE>   32
HOLDER OF A CONVERTIBLE NOTE, AS THE CASE MAY BE, CONSTITUTING NEGLIGENCE OR
WILLFUL MISCONDUCT.

                   (v)  THE COMPANY WAIVES ALL RIGHTS OF NOTICE AND HEARING OF
ANY KIND PRIOR TO THE EXERCISE BY THE COLLATERAL AGENT, THE SENIOR NOTE TRUSTEE
OR ANY HOLDER OF A SENIOR NOTE, THE CONVERTIBLE NOTE TRUSTEE OR ANY HOLDER OF A
CONVERTIBLE NOTE OF ITS RIGHTS DURING THE CONTINUANCE OF AN EVENT OF DEFAULT TO
REPOSSESS THE COLLATERAL WITH JUDICIAL PROCESS OR TO REPLEVY, ATTACH OR LEVY
UPON THE COLLATERAL OR OTHER SECURITY FOR THE OBLIGATIONS. THE COMPANY WAIVES
THE POSTING OF ANY BOND OTHERWISE REQUIRED OF THE COLLATERAL AGENT, THE SENIOR
NOTE TRUSTEE OR ANY HOLDER OF A SENIOR NOTE OR THE CONVERTIBLE NOTE TRUSTEE OR
ANY HOLDER OF A CONVERTIBLE NOTE IN CONNECTION WITH ANY JUDICIAL PROCESS OR
PROCEEDING TO OBTAIN POSSESSION OF, REPLEVY, ATTACH OR LEVY UPON COLLATERAL OR
OTHER SECURITY FOR THE OBLIGATIONS, TO ENFORCE ANY JUDGMENT OR OTHER COURT ORDER
ENTERED IN FAVOR OF THE COLLATERAL AGENT, THE SENIOR NOTE TRUSTEE OR ANY HOLDER
OF A SENIOR NOTE OR THE CONVERTIBLE NOTE TRUSTEE OR ANY HOLDER OF A CONVERTIBLE
NOTE, OR TO ENFORCE BY SPECIFIC PERFORMANCE, TEMPORARY RESTRAINING ORDER OR
PRELIMINARY OR PERMANENT INJUNCTION THIS SECURITY AGREEMENT OR ANY OTHER
AGREEMENT OR DOCUMENT AMONG THE COMPANY ON THE ONE HAND AND THE COLLATERAL
AGENT, THE SENIOR NOTE TRUSTEE AND/OR THE HOLDERS OF THE SENIOR NOTES ON THE
OTHER HAND.

              (w)  Appointment of Collateral Agent. Pursuant to, and subject to
the provisions of, Section 7.12 of the Senior Note Indenture and of Section 7.12
of the Convertible Note Indenture, the Trustees hereby appoint the Collateral
Agent, and the Collateral Agent accepts appointment, as Collateral Agent under
the terms of this Security Agreement.

              The Collateral Agent may resign at any time by giving written
notice thereof to the Trustees and may be removed at any time with or without
cause by the Trustees acting together. Prior to the effectiveness of any such
resignation or removal, the Trustees acting together shall have the right to
appoint a successor Collateral Agent which shall be a commercial bank organized
or chartered under the laws of the United States of America or any state thereof
having combined capital and surplus of at least $50,000,000. If no successor
Collateral Agent shall have been so appointed by the Trustees acting together,
and shall have accepted such appointment within 30 days after the retiring
Collateral Agent's giving of notice of resignation or the Trustees' removal of
the retiring Collateral Agent, then the retiring Collateral Agent shall, prior
to the effectiveness of its resignation or removal, on behalf of the Senior Note
Trustee, the Holders of the Senior Notes, the Convertible Note Trustee and the
Holders of the Convertible Notes, appoint a successor Collateral Agent, which
shall be a commercial bank organized under the laws of the United States of


                                       32
<PAGE>   33
America or any State thereof having a combined capital and surplus of at least
$50,000,000. Upon the acceptance of any appointment as Collateral Agent
hereunder by a successor Collateral Agent, such successor Collateral Agent shall
thereupon succeed to and become vested with all the rights, powers, privileges
and duties of the retiring Collateral Agent, and the retiring Collateral Agent
shall be discharged from its duties and obligations under this Security
Agreement. After any retiring Collateral Agent's resignation or removal
hereunder as Collateral Agent, the provisions of this Security Agreement shall
inure to its benefit as to any actions taken or omitted to be taken by it while
it was Collateral Agent under this Security Agreement. Any corporation into
which the Collateral Agent may be merged, or with which it may be consolidated,
or any corporation resulting from any merger or consolidation to which the
Collateral Agent shall be a party, shall be Collateral Agent under this Security
Agreement without the execution or filing of any paper or any further act on the
part of the parties hereto.

                            [SIGNATURE PAGE FOLLOWS]


                                       33
<PAGE>   34
         IN WITNESS WHEREOF, the Company has caused this Security Agreement to
be duly executed and delivered as of the day and year first above written.


                                       NWE CAPITAL (CYPRUS) LIMITED



                                       By: /s/ Clayton A. Waite
                                           -------------------------------------
                                       Name: Clayton A. Waite
                                             -----------------------------------
                                       Title: Director
                                              ----------------------------------


              The undersigned, as nominee of the Company to hold as of record
the Company's beneficial interest in one share of CY (pound)1 each of NWE
Capital (Cyprus) Limited (the "Nominee Collateral") for the sole purpose of
compliance with the requirement under Cypriot law that a corporation have two
shareholders of record, does hereby join in this Security Agreement solely for
the purpose of pledging the Nominee Collateral as security in order to secure
the payment and performance of all Obligations by the Company.

              The undersigned hereby grants to the Collateral Agent for the
benefit of the Senior Note Trustee and for the equal and ratable benefit of the
Holders of the Senior Notes and for the benefit of the Convertible Note Trustee
and for the equal and ratable benefit of the Holders of the Convertible Notes
(i) Liens and a continuing security interest in and to the Nominee Collateral in
order to secure the payment and performance of all Obligations by the Company
and (ii) all rights and remedies, whether arising before or after an Event of
Default, with respect to the Nominee Collateral as otherwise granted in this
Security Agreement with respect to the Collateral; provided, however, that the
Collateral Agent, the Senior Note Trustee and the Convertible Note Trustee agree
that, notwithstanding anything contained in this Security Agreement to the
contrary, the undersigned shall have no personal liability under, arising out of
or related to this Security Agreement beyond the Nominee Collateral pledged
hereunder.



                                       /s/ Clayton A. Waite
                                       -----------------------------------------
                                       Clayton A. Waite
<PAGE>   35
         By its acceptance hereof, as of the day and year first above written,
the Collateral Agent, the Senior Note Trustee and the Convertible Note Trustee
agree to be bound by the provisions hereof.


                                       THE BANK OF NEW YORK, as Collateral
                                       Agent, Senior Note Trustee and
                                       Convertible Note Trustee


                                       By: /s/ Steven D. Torgeson
                                           -------------------------------------
                                       Name: Steven D. Torgeson
                                             -----------------------------------
                                       Title: Assistant Treasurer
                                              ----------------------------------
<PAGE>   36
                                                            SCHEDULE A to NWE
                                                            Cyprus Senior Note
                                                            Security and Pledge
                                                            Agreement


                                  PLEDGED STOCK



20,000,002 ordinary shares of US $1 each of Wireless Technology Corporations
Limited
<PAGE>   37
                                                            SCHEDULE B to NWE
                                                            Cyprus Senior Note
                                                            Security and Pledge
                                                            Agreement

                  EXCEPTIONS TO REPRESENTATIONS AND WARRANTIES


                                      None.
<PAGE>   38
                                                            SCHEDULE C to NWE
                                                            Cyprus Senior Note
                                                            Security and Pledge
                                                            Agreement

                                     FILINGS



1.       UCC-1 financing statements filed with the Secretary of State of the
         State of New York.

2.       UCC-1 financing statements filed with the City Registers Office, New
         York County, New York.

3.       The share register of WTC must contain each of the following:

         a.       A statement that the WTC Capital Stock is pledged

         b.       The name of the pledgees

         c.       The date on which the statement and name contained in (a) and
                  (b) above are entered in the share register
<PAGE>   39
                                                            SCHEDULE D to NWE
                                                            Cyprus Senior Note
                                                            Security and Pledge
                                                            Agreement

                             CHIEF EXECUTIVE OFFICES



                             Iris Tower, Office 602
                          58 Arch. Makarios III Avenue
                                 Nicosia, CYPRUS
<PAGE>   40
                                                            SCHEDULE E to NWE
                                                            Cyprus Senior Note
                                                            Security and Pledge
                                                            Agreement

                                 BUSINESS NAMES



                                      None.
<PAGE>   41
                                                            SCHEDULE F to NWE
                                                            Cyprus Senior Note
                                                            Security and Pledge
                                                            Agreement

                             LOCATION OF COLLATERAL



                                 See Schedule D.
<PAGE>   42
                                                            SCHEDULE G
                                                            Additional
                                                            Collateral Amendment


         This Additional Collateral Amendment, dated _____________, 19__, is
delivered pursuant to Section 6(a) of the Security Agreement referred to below.
The undersigned hereby pledges to the Collateral Agent for the benefit of the
Senior Note Trustee and the equal and ratable benefit of the Holders of the
Senior Notes, and grants to the Collateral Agent for its benefit and the equal
and ratable benefit of the Holders of the Senior Notes, continuing Liens and
security interest in all of its rights, title and interest in the Collateral
listed below.

         The undersigned hereby agrees that this Additional Collateral Amendment
may be attached to the Security and Pledge Agreement, dated as of May 31, 1996,
between the undersigned and The Bank of New York, as Senior Note Trustee, as
Convertible Note Trustee and as Collateral Agent (the "Security Agreement");
capitalized terms used herein and not otherwise defined herein shall have the
meanings given to such terms in the Security Agreement; and the Collateral
listed on this Additional Collateral Amendment shall be deemed to be part of the
Collateral, and shall become part of the Collateral and shall secure all
Obligations.


                                       NWE CAPITAL (CYPRUS) LTD.


                                       By:________________________________
                                       Name:______________________________
                                       Title:_____________________________


WTC CAPITAL STOCK:


<TABLE>
<CAPTION>
                      Number of            Share             Percentage
   Name of             Shares           Certificate           of Shares
  Guarantor           Pledged              Number            Outstanding
  ---------           ---------         -----------          -----------
<S>                   <C>               <C>                  <C>    

</TABLE>



                                       3
<PAGE>   43
INTERCOMPANY NOTES:


<TABLE>
<CAPTION>
                Description       Name of Restricted                 Original
    Item             of               Subsidiary                     Principal
   Number       Indebtedness           (Obligor)         Date         Amount
   ------       ------------      ------------------     ----        ---------
<S>             <C>               <C>                    <C>         <C>    

</TABLE>
<PAGE>   44
                                                            SCHEDULE H to NWE
                                                            Cyprus Senior Note
                                                            Security and Pledge
                                                            Agreement


                             RESTRICTIVE AGREEMENTS



1.       The BECET charter and joint venture agreement provide that a joint
         venture partner may not sell, assign, pledge or otherwise transfer its
         shares without the written consent of the other partner prior to
         February 4, 1999. After February 4, 1999, such interest may be
         transferred provided that the transferee agrees to be bound by the
         terms of the joint venture agreement creating BECET.

2.       The BECET charter provides that dividends may be established at a
         meeting of the General Assembly (as defined therein). To the extent
         that WTC owns a 50 percent equity interest in BECET, its ability to
         cause BECET to declare dividends may be restricted.

3.       The BECET charter provides a right of first refusal for newly issued
         shares.