<PAGE>


                                                                   EXHIBIT 4.106

                                                          CLIFFORD CHANCE US LLP

                                                                  CONFORMED COPY

                   MARCONI COMMUNICATIONS NORTH AMERICA INC.,
                                   AS PLEDGOR

                                       AND

                   THE LAW DEBENTURE TRUST CORPORATION p.l.c.,
                                AS SECURED PARTY

   ---------------------------------------------------------------------------

                               SECURITY AGREEMENT

   ---------------------------------------------------------------------------

<PAGE>

                                TABLE OF CONTENTS

<TABLE>
<CAPTION>
SECTION                                                                                                   PAGE
<S>                                                                                                       <C>
Section 1.      Definitions...........................................................................      1

Section 2.      Grant of Security Interest.............................................................     4

Section 3.      Authorization; Responsibility..........................................................     5

Section 4.      Relation to Other Security Documents...................................................     5

Section 5.      Representations and Warranties.........................................................     6

Section 6.      Covenants..............................................................................     6

Section 7.      Limitations on Requirements as to Perfection...........................................    11

Section 8.      Inspection and Verification............................................................    12

Section 9.      Collateral Protection Expenses; Preservation of Collateral.............................    12

Section 10.     Securities and Deposits................................................................    13

Section 11.     Notification to Account Debtors and Other Persons Obligated on Collateral..............    13

Section 12.     Power of Attorney......................................................................    14

Section 13.     Remedies...............................................................................    15

Section 14.     Standards for Exercising Remedies......................................................    15

Section 15.     Waivers by Pledgor; Obligations Absolute...............................................    16

Section 16.     Marshalling............................................................................    17

Section 17.     Proceeds of Dispositions...............................................................    17

Section 18.     Amounts Due Hereunder..................................................................    17

Section 19.     Termination............................................................................    17

Section 20.     Reinstatement..........................................................................    17

Section 21.     Miscellaneous..........................................................................    18

Exhibit A  UCC PERFECTION CERTIFICATE
Exhibit B  FORM OF COPYRIGHT SECURITY AGREEMENT SUPPLEMENT
Exhibit C  FORM OF PATENT SECURITY AGREEMENT SUPPLEMENT
Exhibit D  FORM OF TRADEMARK SECURITY AGREEMENT SUPPLEMENT
</TABLE>

<PAGE>

         SECURITY AGREEMENT (this "AGREEMENT") dated as of May 19, 2003, between
MARCONI COMMUNICATIONS NORTH AMERICA INC., a Delaware corporation ("PLEDGOR"),
and THE LAW DEBENTURE TRUST CORPORATION p.l.c. ("LAW DEBENTURE"), as Security
Trustee (together with any co-trustee, co-agent or other entity appointed
pursuant to clause 16 of the STID (as defined below) ("SECURED PARTY") under the
Security Trust and Intercreditor Deed dated the date hereof and made among
Marconi Corporation plc as Issuer; Secured Party; the persons listed in Schedule
1 thereto as Guarantors; Law Debenture Trust Company of New York as Senior Note
Trustee; JPMorgan Chase Bank as Junior Note Trustee; HSBC Bank plc as New
Bonding Facility Agent and Escrow Bank; The Bank of New York as Depositary,
Paying Agent and Registrar; the persons listed in Part A of Schedule 2 thereto
as Intra-Group Creditors; the persons listed in Part B of Schedule 2 thereto as
Intra-Group Borrowers; and the persons listed in Schedule 3 thereto as New
Bonding Facility Banks (as amended, modified or supplemented from time to time,
the "STID").

         WHEREAS, Pledgor has entered into (i) the Guarantee of Senior Notes,
(ii) the Guarantee of Junior Notes and (iii) the Composite Guarantee, each dated
the date hereof in favor of Secured Party (collectively, the "GUARANTEES"),
pursuant to which Pledgor has agreed to guarantee certain obligations and to
secure those obligations and, in connection therewith, inter alia, to execute
and deliver to Secured Party a security agreement in substantially the form
hereof;

         NOW, THEREFORE, in consideration of the premises and for other good and
valuable consideration the receipt and sufficiency of which are hereby
acknowledged, the parties hereto agree as follows:

         Section 1.        DEFINITIONS.

                     1.01.    Definition of Terms Used Herein Generally. Unless
otherwise defined herein, terms defined in the STID and used herein have the
meanings given to them in the STID. All terms used herein and defined in the
NYUCC shall have the same definitions herein as specified therein; provided,
however, that if a term is defined in Article 9 of the NYUCC differently than in
another Article of the NYUCC, the term has the meaning specified in Article 9 of
the NYUCC.

                     1.02.    Definition of Certain Terms Used Herein. As used
herein, the following terms shall have the following meanings:

         "COLLATERAL" shall have the meaning assigned to such term in Section 2.

         "COPYRIGHT LICENSE" shall mean any written agreement, now or hereafter
in effect, granting any right to any third party under any Copyright now or
hereafter owned by Pledgor or that Pledgor otherwise has the right to license,
or granting any right to Pledgor under any Copyright now or hereafter owned by
any third party or that any third party otherwise has the right to license, and
all rights of Pledgor under any such agreement.

         "COPYRIGHT OFFICE" shall mean the United States Copyright Office.

         "COPYRIGHT SECURITY AGREEMENT SUPPLEMENT" shall mean a supplement to
this Agreement, executed by Pledgor in favor of Secured Party, substantially in
the form of Exhibit B hereto.

<PAGE>

                                                                               2

         "COPYRIGHTS" shall mean (a) all copyright rights in any work subject to
the copyright laws of the United States or any other country, whether as author,
assignee, transferee or otherwise, and (b) all registrations and applications
for registration of any such copyright in the United States or any other country
and all extensions and renewals thereof.

         "DEFAULT" shall mean any event or circumstance that constitutes a
Default under the Senior Note Indenture or the Junior Note Indenture.

         "DEPOSITARY" shall have the meaning assigned to such term in the
Deposit Account Control Agreement.

         "DEPOSIT ACCOUNT CONTROL AGREEMENT" shall mean an agreement in form and
substance satisfactory to Secured Party, pursuant to which the relevant
depositary bank agrees, inter alia, to comply with instructions originated by
Secured Party directing disposition of the funds in the relevant deposit account
without further consent by Pledgor, and not to comply with any instructions
originated by Pledgor directing disposition of such funds, in each case upon
receipt by such depositary bank of a written notice from Secured Party to such
effect.

         "EVENT OF DEFAULT" shall mean any event or circumstance that
constitutes an Event of Default under the Senior Note Indenture or the Junior
Note Indenture.

         "GOVERNMENT DEBTOR" shall have the meaning assigned to such term in
Section 5.01(a).

         "INTELLECTUAL PROPERTY" shall mean all intellectual and similar
property of Pledgor of every kind and nature now owned or hereafter acquired by
Pledgor, including inventions, designs, Patents, Patent Licenses, Trademarks,
Trademark Licenses, Copyrights, Copyright Licenses, trade secrets, confidential
or proprietary technical and business information, know-how, show-how or other
data or information, software and databases and all embodiments or fixations
thereof and related documentation, registrations and franchises, licenses for
any of the foregoing and all license rights, and all additions, improvements and
accessions to, and books and records describing or used in connection with, any
of the foregoing.

         "LIEN" shall have the meaning assigned to the term "Security" in the
STID.

         "NYUCC" shall mean the Uniform Commercial Code as in effect in the
State of New York from time to time.

         "PATENT LICENSE" shall mean any written agreement, now or hereafter in
effect, granting to any third party any right to make, use or sell any invention
on which a Patent, now or hereafter owned by Pledgor or that Pledgor otherwise
has the right to license, is in existence, or granting to Pledgor any right to
make, use or sell any invention on which a Patent, now or hereafter owned by any
third party, is in existence or that any third party otherwise has the right to
license, and all rights of Pledgor under any such agreement.

         "PATENT SECURITY AGREEMENT SUPPLEMENT" shall mean a supplement to this
Agreement, executed by Pledgor in favor of Secured Party, substantially in the
form of Exhibit C hereto.

         "PATENTS" shall mean (a) all letters patent of the United States or any
other country, all registrations and recordings thereof, and all pending
applications for letters patent of the United States or any other country,
including registrations, recordings and applications in the PTO or in any
similar office

<PAGE>

                                                                               3

or agency of the United States, any State or Territory thereof, or any other
country, and (b) all reissues, continuations, divisions, continuations-in-part,
renewals or extensions thereof and the inventions disclosed or claimed therein,
including the right to make, use and/or sell inventions disclosed or claimed
therein.

         "PERFECTION CERTIFICATE" shall mean a certificate substantially in the
form of Exhibit A hereto, completed and supplemented with the schedules and
attachments contemplated thereby, and duly executed by Pledgor.

         "PERFECTION SUPPLEMENT" shall have the meaning assigned to such term in
Section 6.14.

         "PTO" shall mean the United States Patent and Trademark Office.

         "SECURED OBLIGATIONS" shall mean all present and future indebtedness,
liabilities and obligations (for the avoidance of doubt, including any
liabilities and obligations which have been cash-collateralized by the Pledgor)
at any time of the Pledgor under the Relevant Documents, both actual and
contingent and whether incurred solely or jointly or in any other capacity
together with any of the following matters relating to or arising in respect of
those liabilities and obligations:.

         (a)      any refinancing, novation, deferral or extension;

         (b)      any obligation relating to any increase in the amount of such
                  obligations;

         (c)      any claim for damages or restitution; and

         (d)      any claim as a result of any recovery by the Pledgor of a
                  payment or discharge, or non-allowability, on the grounds of
                  preference,

and any amounts that would be included in any of the above but for any
discharge, non-provability or unenforceability of those amounts in any
insolvency or other proceedings (including interest accruing after the
commencement of any insolvency or other proceedings).

         "SECURITY DOCUMENTS" shall mean this Agreement, the Perfection
Certificate, the Stock Pledge Agreement, the Deposit Account Control Agreements
and the other documents, agreements and supplements to be executed pursuant to
the terms hereof, each as entered into, or as shall be entered into, by Pledgor.

         "SECURITY INTEREST" shall mean the security interest granted pursuant
to Section 2, as well as all other security interests created or assigned as
additional security for the Secured Obligations pursuant to the provisions of
this Agreement.

         "STID" shall have the meaning assigned to such term in the preamble to
this Agreement.

         "STOCK PLEDGE AGREEMENT" shall mean the stock pledge agreement dated on
or about the date hereof between Secured Party and Pledgor.

         "TRADEMARK LICENSE" shall mean any written agreement, now or hereafter
in effect, granting to any third party any right to use any Trademark now or
hereafter owned by Pledgor or that Pledgor otherwise has the right to license,
or granting to Pledgor any right to use any Trademark now or hereafter owned by
any third party or that any third party otherwise has the right to license, and
all rights of Pledgor under any such agreement.

<PAGE>

                                                                               4

         "TRADEMARK SECURITY AGREEMENT SUPPLEMENT" shall mean a supplement to
this Agreement, executed by Pledgor in favor of Secured Party, substantially in
the form of Exhibit D hereto.

         "TRADEMARKS" shall mean (a) all trademarks, service marks, trade names,
corporate names, company names, business names, fictitious business names, trade
styles, trade dress, logos, other source or business identifiers, designs and
general intangibles of like nature, now existing or hereafter adopted or
acquired, all registrations and recordings thereof, and all registration and
recording applications filed in connection therewith, including registrations
and registration applications in the PTO, any State of the United States or any
similar offices in any other country or any political subdivision thereof, and
all extensions or renewals thereof, (b) all goodwill associated therewith or
symbolized thereby and (c) all other assets, rights and interests that uniquely
reflect or embody such goodwill.

         "UCC" shall mean the Uniform Commercial Code as in effect in any
jurisdiction (except as otherwise contemplated in Section 6.15). References to
particular sections of Article 9 of the UCC shall be, unless otherwise
indicated, references to Revised Article 9 of the UCC adopted and effective in
certain jurisdictions on or after July 1, 2001.

                  1.03.    Rules of Interpretation.

The rules of interpretation specified in clause 1.2 of the STID shall be
applicable to this Agreement.

"continuing" in relation to an Enforcement Event shall be construed as a
reference to an acceleration of any Secured Obligation (other than Secured
Obligations arising under the New Bonding Facility Agreement) where such
acceleration has not been rescinded in writing or a declaration that the Secured
Obligations (other than Secured Obligations arising under the New Bonding
Facility Agreement) are prematurely due and payable (other than solely as a
result of it becoming unlawful for a Secured Creditor to perform its obligations
under the Relevant Documents) where such declaration has not been revoked in
writing or any failure by an Obligor to pay any principal amount in respect of
any Secured Obligations (other than Secured Obligations arising under the New
Bonding Facility Agreement) whether on maturity or otherwise which has not been
waived in writing. For purposes of this clause, "Secured Obligations" shall have
the meaning assigned to such term in the STID.

                  1.04.    STID. The parties hereto acknowledge that Secured
Party, when acting hereunder, shall be acting in accordance with and subject to
the terms of the STID.

                  1.05.    Conflict. Notwithstanding any provision to the
contrary contained herein, the parties agree that this Agreement is subject in
all respects to the STID and for the avoidance of doubt, in the event of any
inconsistency, the provisions of the STID shall prevail.

         Section  2.       GRANT OF SECURITY INTEREST. To secure the payment or
performance, as the case may be, in full of the Secured Obligations, Pledgor
hereby grants to Secured Party a security interest in and mortgage on and
pledges and assigns to Secured Party, its successors and assigns the following
properties, assets and rights of Pledgor, wherever located, whether now owned or
hereafter acquired or arising, and all proceeds and products thereof (all of the
same being hereinafter called the "COLLATERAL"): all personal property and
fixtures of every kind and nature, including without limitation all goods
(including without limitation inventory, equipment and any accessions thereto),
instruments (including without limitation promissory notes), documents, accounts
(including

<PAGE>

                                                                               5

without limitation health-care-insurance receivables), chattel paper (whether
tangible or electronic), deposit accounts, letter-of-credit rights (whether or
not the letter of credit is evidenced by a writing), money, tort claims,
securities and all other investment property, supporting obligations, any other
contract rights or rights to the payment of money, insurance claims and
proceeds, and all general intangibles (including without limitation all
Intellectual Property, insurance policies and payment intangibles). Secured
Party acknowledges that the attachment of its security interest in any
commercial tort claim as original collateral is subject to Pledgor's compliance
with Section 6.10.

         Section 3.        AUTHORIZATION; RESPONSIBILITY .

         3.01.    Authorization to File Financing Statements. Pledgor hereby
irrevocably authorizes Secured Party at any time and from time to time to file
in any jurisdiction in which the UCC has been adopted any initial financing
statements and amendments thereto that (a) indicate the Collateral (i) as all
assets of Pledgor or words of similar effect, regardless of whether any
particular asset comprised in the Collateral falls within the scope of Article 9
of the NYUCC or such jurisdiction, or (ii) as being of an equal or lesser scope
or with greater detail, and (b) contain any other information required by part 5
of Article 9 of the UCC for the sufficiency or filing office acceptance of any
initial financing statement or amendment, including (i) the type of organization
of Pledgor and any organization identification number issued to Pledgor and,
(ii) in the case of a financing statement filed as a fixture filing or
indicating Collateral as timber to be cut or as-extracted collateral, a
sufficient description of real property to which such Collateral relates.
Pledgor agrees to furnish any such information to Secured Party promptly upon
request. Pledgor also ratifies its authorization for Secured Party to have filed
in any UCC jurisdiction any like initial financing statements or amendments
thereto if filed prior to the date hereof. The authorization conferred on
Secured Party under this Section 3 is solely to protect Secured Party's interest
in the Pledged Collateral and shall not impose any duty on Secured Party to act.

                  3.02.    No Responsibility to Perfect. Clause 14.8 of the STID
is hereby incorporated herein by this reference with the same effect as though
set forth in its entirety herein.

         Section  4.       RELATION TO OTHER SECURITY DOCUMENTS. The provisions
of this Agreement supplement the provisions of any real estate mortgage or deed
of trust granted by Pledgor to Secured Party and securing the payment or
performance of any of the Secured Obligations. Nothing contained in any such
real estate mortgage or deed of trust shall derogate from any of the rights or
remedies of Secured Party hereunder.

                  4.01.    Other Security Documents. Concurrently herewith
Pledgor is executing and delivering to Secured Party the other Security
Documents. All collateral covered by such other Security Documents shall be
governed by the terms of such other Security Documents and not by the terms of
this Agreement (to the extent that the terms of such other Security Documents
conflict with the terms hereof).

                  4.02.    Omitted.

                  4.03.    Omitted.

<PAGE>

                                                                               6

         Section 5.        REPRESENTATIONS AND WARRANTIES. Pledgor represents
and warrants to Secured Party as follows:

                  5.01.    Nature of Collateral. None of the Collateral
constitutes, or is the proceeds of, farm products and none of the Collateral has
been purchased will be used by Pledgor primarily for personal, family or
household purposes, and except as indicated in the Perfection Certificate:

                           (a)      none of the account debtors or other persons
obligated on any of the Collateral is a governmental authority subject to the
Federal Assignment of Claims Act or like federal, state or local statute or rule
in respect of such Collateral (a "GOVERNMENT DEBTOR"), which Collateral has a
value of at least $1,000,000, and, in the case of Collateral that is a contract,
also has a term of at least one (1) year.

                           (b)      Pledgor holds no commercial tort claims.

                  5.02.    Perfection Certificate; Perfection.

                           (a)      All information set forth on the Perfection
Certificate is, and all information set forth on each Perfection Supplement
shall be, accurate and complete.

                           (b)      Omitted.

         Section 6.        COVENANTS. Pledgor covenants and agrees with
Secured Party, in each case at Pledgor's own cost and expense, as follows.

                  6.01.    Pledgor's Name, Legal Status, Locations. Without
providing at least thirty (30) days' prior written notice to Secured Party,
Pledgor shall not change (a) its name; (b) its type of organization, its
jurisdiction or organization or other legal structure; or (c) its place of
business or (if it has more than one place of business) its chief executive
office or its mailing address.

                  6.02.    Pledgor's Organizational Number. Without providing at
least thirty (30) days' prior written notice to Secured Party, Pledgor shall not
change its organizational identification number if it has one. If Pledgor does
not have an organizational identification number and later obtains one, Pledgor
shall forthwith notify Secured Party of such organizational identification
number.

                  6.03.    Title to Collateral. (a) Except for the Security
Interest herein granted and Liens not expressly prohibited by the Indentures,
Pledgor shall be the owner of the Collateral free from (and Pledgor shall not
create or suffer to exist on the Collateral) any Lien; and (b) Pledgor shall not
pledge, mortgage or create, or suffer to exist a Lien on the Collateral in favor
of any person other than Secured Party except for Liens permitted by the
Indentures.

                  6.04.    Promissory Notes and Tangible Chattel Paper. Subject
to Section 7, if Pledgor shall at any time hold or acquire any promissory notes
or tangible chattel paper, Pledgor shall forthwith endorse, assign and deliver
the same to Secured Party, accompanied by such instruments of transfer or
assignment duly executed in blank as Secured Party may from time to time specify
and with respect to any such Collateral in the possession or control of Secured
Party, Pledgor waives any restriction or obligation imposed on Secured Party by
Sections 9-207(c)(1) and 9-207(c)(2) of the NYUCC. Secured Party agrees that,
upon written request from Pledgor certifying that Pledgor requires possession of
a promissory note or tangible chattel paper then in the possession of Secured
Party in order to enforce the

<PAGE>

                                                                               6

same, it shall deliver to Pledgor such promissory note or tangible chattel paper
to Pledgor; Pledgor agrees that such promissory note or tangible chattel paper
shall be held to the order of Secured Party.

                  6.05.    Deposit Accounts. Subject to Section 7, for each
deposit account that Pledgor at any time opens or maintains, Pledgor shall cause
the depositary bank to enter into a Deposit Account Control Agreement. Secured
Party agrees with Pledgor that Secured Party shall not give to any Depositary
the notice referred to in Section 2.01 of the Deposit Account Control Agreement
or withhold any withdrawal rights from Pledgor, unless an Enforcement Event has
occurred and is continuing. The foregoing provisions of this Section 6.05 shall
not apply to (i) deposit accounts for which Secured Party is the depositary bank
and (ii) deposit accounts specially and exclusively used for payroll, payroll
taxes and other employee wage and benefit payments to or for the benefit of
Pledgor's salaried employees. With respect to any deposit accounts, rights
arising under deposit accounts or proceeds thereof in the possession or within
the control of Secured Party, Pledgor waives any restriction or obligation
imposed on Secured Party by Sections 9-207(c)(1), 9-207(c)(2) and 9-208 of the
NYUCC.

                  6.06.    Investment Property. If Pledgor shall at any time
hold or acquire any certificated securities, Pledgor shall forthwith endorse,
assign and deliver the same to Secured Party, accompanied by such instruments of
transfer or assignment duly executed in blank as Secured Party may from time to
time specify. If any securities now owned or hereafter acquired by Pledgor are
uncertificated and are issued to Pledgor or its nominee directly by the issuer
thereof, Pledgor shall immediately notify Secured Party thereof and shall cause
the issuer to enter into a written agreement or other authenticated record with
Secured Party, in form and substance satisfactory to Secured Party, pursuant to
which such issuer shall agree, among other things, to comply with instructions
from Secured Party as to such securities, without further consent of Pledgor or
such nominee; in the event Pledgor is unable or otherwise fails to obtain such
written agreement or other authenticated record from an issuer, Pledgor shall
arrange for Secured Party or a Delegate to become the registered owner of the
securities. If any securities, whether certificated or uncertificated, or other
investment property now or hereafter acquired by Pledgor are held or acquired by
Pledgor or its nominee through a securities intermediary or commodity
intermediary, Pledgor shall immediately notify Secured Party thereof and shall
cause such securities intermediary or (as the case may be) commodity
intermediary to enter into a written agreement or other authenticated record
with Secured Party, in form and substance satisfactory to Secured Party,
pursuant to which such securities intermediary or commodities intermediary, as
the case may be, shall, among other things, agree to comply with entitlement
orders or other instructions from Secured Party to such securities intermediary
as to such securities or other investment property, or (as the case may be) to
apply any value distributed on account of any commodity contract as directed by
Secured Party to such commodity intermediary, in each case without further
consent of Pledgor or such nominee; in the event Pledgor is unable or otherwise
fails to obtain such written agreement or other authenticated record from a
securities intermediary or commodities intermediary, as the case may be, Pledgor
shall, in the case of financial assets or other investment property held through
a securities intermediary, arrange for Secured Party or a Delegate to become the
entitlement holder with respect to such investment property, with Pledgor being
permitted, only with the consent of Secured Party (acting on instructions
received pursuant to the terms of the STID), to exercise rights to withdraw or
otherwise deal with such investment property. Secured Party agrees with Pledgor
that Secured Party shall not give any such entitlement orders or instructions or
directions to any such issuer, securities intermediary or commodity
intermediary, and shall not withhold

<PAGE>

                                                                               8

its consent to the exercise of any withdrawal or dealing rights by Pledgor,
unless an Enforcement Event has occurred and is continuing or, after giving
effect to any such investment and withdrawal rights not otherwise permitted by
the Relevant Documents, a Default or Event of Default would occur. The
provisions of this Section 6.06 shall not apply to any financial assets credited
to a securities account for which Secured Party is the securities intermediary.
With respect to any such Collateral in the possession or within the control of
Secured Party, Pledgor waives any restriction or obligation imposed on Secured
Party by Sections 9-207(c)(1), 9-207(c)(2) and 9-208 of the NYUCC.

                  6.07.    Collateral in the Possession of a Bailee. Subject to
Section 7, if any goods are at any time in the possession of a bailee (which
bailee has agreed to hold or in fact holds such goods for more than ninety (90)
days), Pledgor shall promptly notify Secured Party thereof and shall use
commercially reasonable efforts promptly to obtain an acknowledgement from such
bailee, in form and substance satisfactory to Secured Party, that such bailee
holds such Collateral for the benefit of Secured Party and shall act upon the
instructions of Secured Party, without the further consent of Pledgor. Secured
Party agrees with Pledgor that Secured Party shall not give any such
instructions unless an Enforcement Event has occurred and is continuing or a
Default or Event of Default would occur after taking into account any action by
Pledgor with respect to such bailee. With respect to any such Collateral in the
possession or within the control of Secured Party or a bailee, Pledgor waives
any restriction or obligation imposed on Secured Party by Sections 9-207(c)(1)
and 9-207(c)(2) of the UCC.

                  6.08.    Electronic Chattel Paper and Transferable Records.
Subject to Section 7, if Pledgor at any time holds or acquires an interest in
any electronic chattel paper or any "transferable record," as that term is
defined in Section 201 of the federal Electronic Signatures in Global and
National Commerce Act, or in Section 16 of the Uniform Electronic Transactions
Act as in effect in any relevant jurisdiction, Pledgor shall promptly notify
Secured Party thereof and shall use commercially reasonable efforts to vest in
Secured Party control, under Section 9-105 of the UCC, of such electronic
chattel paper or control under Section 201 of the federal Electronic Signatures
in Global and National Commerce Act or, as the case may be, Section 16 of the
Uniform Electronic Transactions Act, as so in effect in such jurisdiction, of
such transferable record. Secured Party agrees with Pledgor that Secured Party
shall arrange, pursuant to procedures satisfactory to Secured Party and so long
as such procedures will not result in Secured Party's loss of control, for
Pledgor to make alterations to the electronic chattel paper or transferable
record permitted under Section 9-105 of the UCC or, as the case may be, Section
201 of the federal Electronic Signatures in Global and National Commerce Act or
Section 16 of the Uniform Electronic Transactions Act, unless an Enforcement
Event has occurred and is continuing or a Default or Event of Default would
occur after taking into account any action by Pledgor with respect to such
electronic chattel paper or transferable record. With respect to any such
Collateral in the possession or within the control of Secured Party, Pledgor
waives any restriction or obligation imposed on Secured Party by Sections
9-207(c)(1), 9-207(c)(2) and 9-208 of the NYUCC.

                  6.09.    Letter of Credit Rights. Subject to Section 7, if
Pledgor is at any time a beneficiary under a letter of credit now or hereafter
issued in favor of Pledgor with a term of ninety (90) days or longer, Pledgor
shall promptly notify Secured Party thereof and Pledgor shall use commercially
reasonable efforts to arrange, for the issuer and any nominated person with
respect to such letter of credit to consent, pursuant to an agreement or other
authenticated record with and in form and substance

<PAGE>

                                                                               9

satisfactory to Secured Party, to an assignment to Secured Party of the proceeds
of any drawing under the letter of credit ; in the event Pledgor is unable or
otherwise fails to obtain such agreement or other authenticated record from an
issuer, Pledgor shall arrange for Secured Party or a Delegate to become the
transferee beneficiary of the letter of credit, with Secured Party agreeing, in
each case, that the proceeds of any drawing under the letter of credit are to be
applied as provided in the STID. With respect to any such Collateral in the
possession or within the control of Secured Party, Pledgor waives any
restriction or obligation imposed on Secured Party by Sections 9-207(c)(1),
9-207(c)(2) and 9-208 of the NYUCC.

                  6.10.    Commercial Tort Claims. Subject to Section 7, if
Pledgor shall at any time hold or acquire a commercial tort claim, Pledgor shall
upon the assertion of such claim in litigation, arbitration or any other
proceeding (whether by way of the filing of a complaint, counterclaim, cross
claim or otherwise), notify Secured Party in a writing signed by Pledgor of the
brief details thereof and grant to Secured Party in such writing a security
interest therein and in the proceeds thereof, all upon the terms of this
Agreement, with such writing to be in form and substance satisfactory to Secured
Party.

                  6.11.    Intellectual Property.

                           (a)      Pledgor shall within twenty (20) days of (i)
filing an application for the registration of any Patent, Trademark, or
Copyright with the PTO, the Copyright Office or any similar office or agency of
any jurisdiction, and (ii) receiving a notice of any Patent, Trademark or
Copyright registration from the PTO, the Copyright Office or any similar office
or agency of any jurisdiction (whether by itself or through any agent, employee,
licensee or designee) give Secured Party written notice thereof, and shall
execute and deliver to Secured Party any and all Patent Security Agreement
Supplements, Trademark Security Agreement Supplements or Copyright Security
Agreement Supplements as Secured Party may request to evidence Secured Party's
Security Interest in such Patent, Trademark or Copyright, and the general
intangibles of Pledgor relating thereto or represented thereby.

                           (b)      Pledgor shall take all actions requested by
Secured Party to maintain and pursue each application, to obtain the relevant
registration and to maintain the registration of its Patents or Trademarks (now
or hereafter existing), including the filing of applications for renewal,
affidavits of use, affidavits of noncontestability and opposition and
interference and cancellation proceedings, unless Pledgor shall reasonably
determine that such Patent or Trademark is not material to the conduct of its
business.

                           (c)      With respect to any Intellectual Property
constituting Collateral that Pledgor has reasonably determined continues to be
useful and material to the conduct of Pledgor's business, Pledgor shall manage
such Intellectual Property consistent with its past practices related to
prosecution, maintenance, dedication to the public, abandonment, protection and
enforcement of Intellectual Property.

                           (d)      Pledgor assumes all responsibility and
liability arising from the use of the Intellectual Property and hereby
indemnifies and holds Secured Party and each other Secured Creditor harmless
from and against any claim, suit, loss, damage or expense (including attorneys'
fees arising out of any alleged defect in any product manufactured, promoted or
sold by Pledgor (or any affiliate or subsidiary thereof) in connection with such
Intellectual Property or out of the manufacture, promotion, labelling, sale or
advertisement of any such product by Pledgor (or any affiliate or subsidiary
thereof).

<PAGE>

                                                                              10

                  6.12.    Landlord Consents. Pledgor shall use commercially
reasonable efforts to deliver to Secured Party an executed letter in form and
substance acceptable to Secured Party from each landlord from which Pledgor
leases premises on which Goods or Inventory of Pledgor with a book value in
excess of ten million dollars ($10,000,000) is located, stored, used or held in
the United States of America promptly upon the book value of Goods or Inventory
located, stored, used or held at such premises reaching ten million dollars
($10,000,000) (each such letter, a "LANDLORD WAIVER LETTER") pursuant to which
such landlord, among other things, acknowledges the security interest granted by
Pledgor to Secured Party in such Goods and Inventory, waives or subordinates any
Lien such landlord may have in respect of such Goods or Inventory and agrees to
provide the Secured Party with access to such premises upon the occurrence and
during the continuance of an Event of Default.

                  6.13.    Dispositions of Collateral. Pledgor shall not sell or
otherwise dispose, or offer to sell or otherwise dispose, of the Collateral or
any interest therein except for (i) sales and leases of inventory in the
ordinary course of business and (ii) dispositions not expressly prohibited by
the Indentures.

                  6.14.    Periodic Certification. Each year, at the time of
delivery of annual financial statements with respect to the preceding fiscal
year pursuant to Section 4.20 of the Indentures, Pledgor shall deliver to
Secured Party a supplemental perfection certificate (each, a "PERFECTION
SUPPLEMENT") executed by Pledgor setting forth the information required pursuant
to the Perfection Certificate or confirming that there has been no change in
such information since the date of such certificate or the date of the most
recent certificate delivered pursuant to this Section 6.14.

                  6.15.    Other Actions as to any and all Collateral. Pledgor
further agrees to take any other action requested by Secured Party to ensure the
attachment and perfection of, and the ability of Secured Party to enforce, the
Security Interest created or purported to be created, in any and all of the
Collateral or for the exercise of rights and remedies of Secured Party provided
by or pursuant to this Agreement or by law including, without limitation, (a)
executing, delivering and, where appropriate, filing financing statements and
amendments relating thereto under the UCC; (b) causing Secured Party's name to
be noted as secured party on any certificate of title for a titled good if such
notation is a condition to attachment or perfection of, or ability of Secured
Party to enforce, the Security Interest in such Collateral; (c) complying with
any provision of any statute, regulation or treaty of the United States as to
any Collateral if compliance with such provision is a condition to the
attachment or perfection of, or the ability of Secured Party to enforce, the
Security Interest in such Collateral; (d) obtaining governmental and other third
party consents and approvals, including without limitation any consent of any
licensor, lessor or other person obligated on Collateral; (e) obtaining waivers
from mortgagees, bailees, landlords and any other person who has possession of
or any interest in any Collateral or any real property on which any Collateral
may be located, in form and substance satisfactory to Secured Party; and (f)
executing, delivering and recording, where applicable, such other documents or
instruments and taking all actions required by the UCC or by other law, as
applicable in any relevant UCC jurisdiction, or by other law as applicable in
any foreign jurisdiction.

                           6.16.    Federal Assignment of Claims Act. Subject to
Section 7, Pledgor shall (x) within ten (10) Business Days of the existence of a
Governmental Debtor send to such entity a written request that such entity, in
writing (an "ACA LETTER") (i) consent to the security interest granted by
Pledgor to

<PAGE>

                                                                              11

Secured Party in such Collateral, (ii) agree to do such other things as may be
necessary pursuant to the terms of the Collateral, and (iii) to agree that, upon
receipt of notice from Secured Party, such entity will make payments under such
Collateral as Secured Party shall direct; and (y) use commercially reasonable
efforts to deliver to Secured Party, within thirty (30) days of Pledgor's
request sent pursuant to clause (x) above, such ACA Letter executed by such
Governmental Debtor.

         Section 7.        LIMITATIONS ON REQUIREMENTS AS TO PERFECTION. The
covenants of Pledgor set forth in Sections 6.04, 6.05, 6.07, 6.08, 6.09, 6.10
and 6.16 are subject to the following limitations:

                           (a)      Pledgor shall not be required to comply with
the perfection requirements of Section 6.04 except with respect to any
promissory note or item of tangible commercial paper that evidences an
obligation of at least (i) $1,000,000, if there has occurred and is continuing a
Default or an Event of Default, of which occurrence the Issuer has notified the
Senior Note Trustee pursuant to Section 6.19 of the Senior Note Indenture or the
Junior Note Trustee pursuant to Section 6.19 of the Junior Note Indenture or of
which occurrence the Senior Note Trustee, the Holders of the Senior Note, the
Junior Note Trustee or the Holders of the Junior Notes have notified the Issuer
or (ii) $5,000,000, otherwise.

                           (b)      Pledgor shall not be required to comply with
the perfection requirements of Section 6.05 with respect to any bank account
that does not at any time have a credit balance of $150,000. Pledgor shall
within fifteen (15) Business Days after the date of this Agreement deliver to
Secured Party Deposit Account Control Agreements executed by depositary banks
with respect to bank accounts, the aggregate balance of which is at least 50% of
the aggregate balance of all bank accounts that are subject to the perfection
requirements of Section 6.05. Pledgor shall within thirty (30) days after the
date of this Agreement deliver to Secured Party Deposit Account Control
Agreements executed by depositary banks with respect to the remainder of the
bank accounts that are subject to the perfection requirements of Section 6.05.

                           (c)      Pledgor shall not be required to comply with
the perfection requirements of Section 6.07 except with respect to goods agreed
to be held or in fact held by a bailee, which goods have an aggregate book value
at least (i) $1,000,000, if there has occurred and is continuing a Default or an
Event of Default, of which occurrence the Issuer has notified the Senior Note
Trustee pursuant to Section 6.19 of the Senior Note Indenture or the Junior Note
Trustee pursuant to Section 6.19 of the Junior Note Indenture, or of which
occurrence the Senior Note Trustee, the Holders of the Senior Notes, the Junior
Note Trustee or the Holders of the Junior Notes have notified the Issuer or (ii)
$5,000,000, otherwise.

                           (d)      Pledgor shall not be required to comply with
the perfection requirements of Section 6.08 except with respect to any item of
electronic chattel paper or any transferable record that evidences an obligation
of at least (i) $1,000,000, if there has occurred and is continuing a Default or
an Event of Default, of which occurrence the Issuer has notified the Senior Note
Trustee pursuant to Section 6.19 of the Senior Note Indenture or the Junior Note
Trustee pursuant to Section 6.19 of the Junior Note Indenture, or of which
occurrence the Senior Note Trustee, the Holders of the Senior Notes, the Junior
Note Trustee or the Holders of the Junior Notes have notified the Issuer or (ii)
$5,000,000, otherwise.

                           (e)      Pledgor shall not be required to comply with
the perfection requirements of Section 6.09 except with respect to one or more
letters of credit issued by an issuer for the benefit of

<PAGE>

                                                                              12

Pledgor, which letters of credit have an aggregate face amount of at least (i)
$1,000,000, if there has occurred and is continuing a Default or an Event of
Default, of which occurrence the Issuer has notified the Senior Note Trustee
pursuant to Section 6.19 of the Senior Note Indenture or the Junior Note Trustee
pursuant to Section 6.19 of the Junior Note Indenture, or of which occurrence
the Senior Note Trustee, the Holders of the Senior Notes, the Junior Note
Trustee or the Holders of the Junior Notes have notified the Issuer or (ii)
$5,000,000, otherwise.

                           (f)      Pledgor shall not be required to comply with
the perfection requirements of Section 6.10 except with respect to Pledgor's
commercial tort claim or series of related commercial tort claims worth at least
(i) $1,000,000, if there has occurred and is continuing a Default or an Event of
Default, of which occurrence the Issuer has notified the Senior Note Trustee
pursuant to Section 6.19 of the Senior Note Indenture or the Junior Note Trustee
pursuant to Section 6.19 of the Junior Note Indenture, or of which occurrence
the Senior Note Trustee, the Holders of the Senior Notes, the Junior Note
Trustee or the Holders of the Junior Notes have notified the Issuer or (ii)
$5,000,000, otherwise.

                           (g)      Pledgor shall not be required to comply with
the perfection requirements of Section 6.16 except (i) with respect to any item
of Collateral that has a value of at least $1,000,000, and, in the case of
Collateral that is a contract, also has a term of at least one (1) year; and
(ii) if there has occurred and is continuing (a) an Insolvency Event of Default,
(b) an Enforcement Event or (c) the occurrence of any Event of Default with
respect to which the Security Trustee has been instructed under the STID; and
(iii) upon the request of the Secured Party, acting upon instructions pursuant
to the STID.

         Section 8.        INSPECTION AND VERIFICATION. Secured Party and
such Persons as Secured Party may designate shall have the right, as reasonably
required and upon reasonable notice, at Pledgor's own cost and expense, to
inspect the Collateral, all records related thereto (and to make extracts and
copies from such records) and the premises upon which any of the Collateral is
located, to discuss Pledgor's affairs with the officers of Pledgor and its
independent accountants and to verify the validity, amount, quality, quantity,
value, condition and status of, or any other matter relating to, the Collateral,
including by contacting account debtors or others obligated with respect to
Collateral and, in the case of Collateral in the possession of any third person,
the third Person possessing such Collateral.

         Section 9.        COLLATERAL PROTECTION EXPENSES; PRESERVATION OF
COLLATERAL.

                  9.01.    Expenses Incurred by Secured Party. If Pledgor fails
to discharge taxes or other encumbrances at any time levied or placed on any of
the Collateral, make repairs thereto or pay any necessary filing fees or
insurance premiums, Secured Party may, in its discretion, discharge such taxes
and other encumbrances, make such repairs and pay such filing fees or insurance
premiums. Secured Party shall have no obligation to Pledgor to make any such
expenditures, nor shall the making thereof relieve Pledgor of any default.
Pledgor shall reimburse Secured Party immediately upon demand for any such
expenditures pursuant to Section 21.09.

                  9.02.    Secured Party's Obligations and Duties. Anything
herein to the contrary notwithstanding, Pledgor shall remain liable under each
contract or agreement comprised in the Collateral to be observed or performed by
Pledgor thereunder. Secured Party shall not have any obligation or liability
under any such contract or agreement by reason of or arising out of this
Agreement or the receipt by Secured Party of any payment relating to any of the
Collateral, nor shall Secured Party be obligated in

<PAGE>

                                                                              13

any manner to perform any of the obligations of Pledgor under or pursuant to any
such contract or agreement, to make inquiry as to the nature or sufficiency of
any payment received by Secured Party in respect of the Collateral or as to the
sufficiency of any performance by any party under any such contract or
agreement, to present or file any claim, to take any action to enforce any
performance or to collect the payment of any amounts that may have been assigned
to Secured Party or to which Secured Party may be entitled at any time or times.
Secured Party's sole duty with respect to the custody, safe keeping and physical
preservation of the Collateral in its possession, under Section 9-207 of the
NYUCC or otherwise, shall be to deal with such Collateral in the same manner as
Secured Party deals with similar property for its own account.

                  9.03.    Use of Collateral. With respect to any Collateral in
the possession of Secured Party, or a bailee or other third party holding on its
behalf, Secured Party (acting on instructions received pursuant to the terms of
the STID) may, at any time after the occurrence and during the continuance of an
Enforcement Event a, use or operate such Collateral in any manner and to the
extent determined by Secured Party.

         Section 10.       SECURITIES AND DEPOSITS. Without limitation of
Section 6.06, Secured Party (acting on instructions received pursuant to the
terms of the STID) may at any time after the occurrence and during the
continuance of an Enforcement Event, at its option, transfer to itself or any
nominee any securities constituting Collateral, receive any income thereon and
hold such income as additional Collateral or apply it to the Secured Obligations
in accordance with the STID. Whether or not any Secured Obligations are due,
Secured Party may after the occurrence and during the continuance of an
Enforcement Event demand, sue for, collect, or make any settlement or compromise
that it deems desirable with respect to the Collateral. Regardless of the
adequacy of Collateral or any other security for the Secured Obligations, any
deposits or other sums at any time credited by or due from Secured Party to
Pledgor may at any time be applied to or set off against any of the Secured
Obligations whether or not due and owing.

         Section 11.       NOTIFICATION TO ACCOUNT DEBTORS AND OTHER PERSONS
OBLIGATED ON COLLATERAL. If an Enforcement Event shall have occurred and be
continuing, Pledgor shall notify account debtors and other persons obligated on
any of the Collateral of the security interest of Secured Party in any account,
chattel paper, general intangible, instrument or other Collateral and that
payment thereof is to be made directly to Secured Party or to any financial
institution designated by Secured Party as Secured Party's agent therefor, and
Secured Party (acting on instructions received pursuant to the terms of the
STID) may itself, if an Enforcement Event shall have occurred and be continuing,
without notice to or demand upon Pledgor, so notify account debtors and other
persons obligated on Collateral. After the giving of any such notification,
Pledgor shall hold any proceeds of collection of accounts, chattel paper,
general intangibles, instruments and other Collateral received by Pledgor as
trustee for Secured Party without commingling the same with other funds of
Pledgor and shall turn the same over to Secured Party in the identical form
received, together with any necessary endorsements or assignments. Secured Party
may apply the proceeds of collection of accounts, chattel paper, general
intangibles, instruments and other Collateral received by Secured Party to the
Secured Obligations or hold such proceeds as additional Collateral, at the
option of Secured Party in accordance with the STID. The provisions of Section
9-209

<PAGE>

                                                                              14

of the NYUCC shall not apply to any account, chattel paper or payment intangible
as to which notification of assignment has been sent to the account debtor or
other person obligation on the Collateral.

         Section 12.       POWER OF ATTORNEY.

                  12.01.   Appointment and Powers of Secured Party. Pledgor
hereby irrevocably constitutes and appoints Secured Party and any director,
officer or agent thereof, with full power of substitution, as its true and
lawful attorneys-in-fact with full irrevocable power and authority in the place
and stead of Pledgor or in Secured Party's own name, for the purpose of carrying
out the terms of this Agreement, to take any and all appropriate action and to
execute any and all documents and instruments that may be necessary or desirable
to accomplish the purposes of this Agreement and any agreement entered into
pursuant to the terms hereof (including, without limitation, the Deposit Account
Control Agreements) and, without limiting the generality of the foregoing,
hereby gives said attorneys the power and right, on behalf of Pledgor, without
notice to or assent by Pledgor, to do the following:

                           (a)      upon the occurrence and during the
continuance of an Enforcement Event (and in accordance with clauses 9 and 10 of
the STID), and at the expense of Pledgor, generally to sell, transfer, pledge,
license, lease, otherwise dispose of, make any agreement with respect to or
otherwise deal with any of the Collateral in such manner as is consistent with
the NYUCC and as fully and completely as though Secured Party were the absolute
owner thereof for all purposes, and to do at Pledgor's expense, at any time, or
from time to time, all acts and things that Secured Party deems necessary to
protect, preserve or realize upon the Collateral and the Security Interest
therein, in order to effect the intent of this Agreement, all as fully and
effectively as Pledgor might do, including, without limitation: (i) making,
settling and adjusting claims in respect of Collateral under policies of
insurance, endorsing the name of such Pledgor on any check, draft, instrument or
other item of payment for the proceeds of such policies of insurance and for
making all determinations and decisions with respect thereto; (ii) filing and
prosecuting registration and transfer applications with the appropriate federal
or local agencies or authorities with respect to trademarks, copyrights and
patentable inventions and processes; (iii) upon written notice to Pledgor,
exercising voting rights with respect to voting securities, which rights may be
exercised, if Secured Party so elects, with a view to causing the liquidation in
a commercially reasonable manner of assets of the issuer of any such securities;
and (iv) executing, delivering and recording, in connection with any sale or
other disposition of any Collateral, of the endorsements, assignments or other
instruments of conveyance or transfer with respect to such Collateral; and

                           (b)      to the extent that Pledgor's authorization
given in Section 3 is not sufficient to file such financing statements with
respect hereto, with or without Pledgor's signature, or a photocopy of this
Agreement in substitution for a financing statement, as Secured Party may deem
appropriate and to execute in Pledgor's name such financing statements and
amendments thereto and continuation statements that may require Pledgor's
signature.

                  12.02.   Ratification by Pledgor. To the extent permitted by
law, Pledgor hereby ratifies all that said attorneys shall lawfully do or cause
to be done by virtue of this Section 12. This power of attorney is a power
coupled with an interest and is irrevocable.

<PAGE>

                                                                              15

                  12.03.   No Duty on Secured Party. The powers conferred on
Secured Party, its directors, officers and agents pursuant to this Section 12
are solely to protect Secured Party's interests in the Collateral and shall not
impose any duty upon any of them to exercise any such powers. Secured Party
shall be accountable only for the amounts that it actually receives as a result
of the exercise of such powers, and neither it nor any of its officers,
directors, employees or agents shall be responsible to Pledgor for any act or
failure to act, except for Secured Party's own gross negligence or willful
misconduct.

         Section 13.       REMEDIES. In each case below, subject to the
limitations on enforcement by the Secured Party in clauses 9 and 10 of the STID;

                  13.01.   Remedies upon Default. If an Enforcement Event shall
have occurred and be continuing, Secured Party (acting on instructions received
pursuant to the terms of the STID) may, without notice to or demand upon
Pledgor, declare this Agreement to be in default, and Secured Party shall
thereafter have in any jurisdiction in which enforcement hereof is sought, in
addition to all other rights and remedies, the rights and remedies of a secured
party under the NYUCC or the UCC of any other jurisdiction in which Collateral
is located, including, without limitation, the right to take possession of the
Collateral, and for that purpose Secured Party may, so far as Pledgor can give
authority therefor, enter upon any premises on which the Collateral may be
situated and remove the same therefrom. Secured Party may in its discretion
require Pledgor to assemble all or any part of the Collateral at such location
or locations within the jurisdiction(s) of Pledgor's principal office(s) or at
such other locations as Secured Party may reasonably designate. Unless the
Collateral is perishable or threatens to decline speedily in value or is of a
type customarily sold on a recognized market, Secured Party shall give to
Pledgor at least ten (10) days' prior written notice of the time and place of
any public sale of Collateral or of the time after which any private sale or any
other intended disposition is to be made. Pledgor hereby acknowledges that ten
(10) days' prior written notice of such sale or sales shall be reasonable
notice. In addition, Pledgor waives any and all rights that it may have to a
judicial hearing in advance of the enforcement of any of Secured Party's rights
hereunder, including, without limitation, its right following an Enforcement
Event to take immediate possession of the Collateral and to exercise its rights
with respect thereto. The provisions of Section 9-209 of the NYUCC shall not
apply to any account, chattel paper or payment intangible as to which
notification of assignment has been sent to the account debtor. In addition,
Secured Party shall have the right to set off any and all obligations of Secured
Party owing to Pledgor under or pursuant to any Relevant Document, in respect of
Collateral or otherwise, against any and all Secured Obligations and any and all
other obligations under any and all of the Relevant Documents, or any other
instrument or agreement owing by Pledgor or any affiliate of Pledgor to Secured
Party under this Agreement or any of the other Relevant Documents, regardless of
whether any such obligations of Pledgor or any affiliate of Pledgor is mature or
unmature. In the case of unmatured obligations, Secured Party may estimate the
amount thereof in good faith.

         Section 14.       STANDARDS FOR EXERCISING REMEDIES. To the extent
that applicable law imposes duties on Secured Party to exercise remedies in a
commercially reasonable manner, Pledgor acknowledges and agrees (subject to
clause 14 of the STID) that it is not commercially unreasonable for Secured
Party (a) to fail to incur expenses reasonably deemed significant by Secured
Party to prepare Collateral for disposition or otherwise to complete raw
material or work in process into finished goods or

<PAGE>

                                                                              16

other finished products for disposition or to postpone any such disposition
pending any such preparation or processing; (b) to fail to obtain third party
consents for access to Collateral to be disposed of, or to obtain or, if not
required by other law, to fail to obtain governmental or third party consents
for the collection or disposition of Collateral to be collected or disposed of;
(c) to fail to exercise collection remedies against account debtors or other
persons obligated on Collateral or to remove any Lien on or any adverse claims
against Collateral; (d) to exercise collection remedies against account debtors
and other persons obligated on Collateral directly or through the use of
collection agencies and other collection specialists; (e) to advertise
dispositions of Collateral through publications or media of general circulation,
whether or not the Collateral is of a specialized nature; (f) to contact other
persons, whether or not in the same business as Pledgor, for expressions of
interest in acquiring all or any portion of the Collateral; (g) to hire one or
more professional auctioneers to assist in the disposition of Collateral,
whether or not the collateral is of a specialized nature; (h) to dispose of
Collateral by utilizing Internet sites that provide for the auction of assets of
the types included in the Collateral or that have the reasonable capability of
doing so, or that match buyers and sellers of assets; (i) to dispose of assets
in wholesale rather than retail markets; (j) to disclaim disposition warranties;
(k) to purchase insurance or credit enhancements to insure Secured Party against
risks of loss, collection or disposition of Collateral or to provide to Secured
Party a guaranteed return from the collection or disposition of Collateral; or
(l) to the extent deemed appropriate by Secured Party, to obtain the services of
other brokers, investment bankers, consultants and other professionals to assist
Secured Party in the collection or disposition of any of the Collateral. Pledgor
acknowledges that the purpose of this Section 14 is to provide non-exhaustive
indications of what actions or omissions by Secured Party would not be
commercially unreasonable in Secured Party's exercise of remedies against the
Collateral and that other actions or omissions by Secured Party shall not be
deemed commercially unreasonable solely on account of not being indicated in
this Section 14. Without limiting the foregoing, nothing contained in this
Section 14 shall be construed to grant any rights to Pledgor or to impose any
duties on Secured Party that would not have been granted or imposed by this
Agreement or by applicable law in the absence of this Section 14.

         Section 15.       WAIVERS BY PLEDGOR; OBLIGATIONS ABSOLUTE.

                           (a)      Pledgor waives demand, notice, protest,
notice of acceptance of this Agreement, notice of loans made, credit extended,
Collateral received or delivered or other action taken in reliance hereon and
all other demands and notices of any description thereof, all in such manner and
at such time or times as Secured Party may deem advisable. Secured Party shall
have no duty as to the collection or protection of the Collateral or any income
thereon, nor as to the preservation of rights against prior parties, nor as to
the preservation of any rights pertaining thereto beyond the safe custody
thereof as set forth in Section 9.02.

                           (b)      All rights of Secured Party hereunder, the
Security Interest and all obligations of Pledgor hereunder shall be absolute and
unconditional irrespective of (i) any lack of validity or enforceability of the
Indentures, the STID or any other Relevant Document, any agreement with respect
to any of the Secured Obligations or any other agreement or instrument relating
to any of the foregoing, (ii) any change in the time, manner or place of payment
of, or in any other term of, all or any of the Secured Obligations, or any other
amendment or waiver of or any consent to any departure from the Indentures, any
other Relevant Document, or any other agreement or instrument, (iii) any
exchange,

<PAGE>

                                                                              17

release or non-perfection of any Lien on other collateral, or any release or
amendment or waiver of or consent under or departure from or any acceptance of
partial payment thereon and or settlement, compromise or adjustment of any of
the Secured Obligations or of any guarantee, securing or guaranteeing all or any
of the Secured Obligations, or (iv) any other circumstance that might otherwise
constitute a defense available to, or a discharge of, Pledgor in respect of the
Secured Obligations or this Agreement.

         Section 16.       MARSHALLING. Secured Party shall not be required
to marshal any present or future collateral security (including but not limited
to this Agreement and the Collateral) for, or other assurances of payment of,
the Secured Obligations or any of them or to resort to such collateral security
or other assurances of payment in any particular order, and all of its rights
hereunder and in respect of such collateral security and other assurances of
payment shall be cumulative and in addition to all other rights, however
existing or arising. To the extent that it lawfully may, Pledgor hereby agrees
that it shall not invoke any law relating to the marshalling of collateral that
might cause delay in or impede the enforcement of Secured Party's rights under
this Agreement or under any other instrument creating or evidencing any of the
Secured Obligations or under which any of the Secured Obligations is outstanding
or by which any of the Secured Obligations is secured or payment thereof is
otherwise assured, and, to the extent that it lawfully may, Pledgor hereby
irrevocably waives the benefits of all such laws.

         Section 17.       PROCEEDS OF DISPOSITIONS. After deducting all
expenses payable by Pledgor, including, without limitation, under Section
21.09(a), and after making any payments required by Sections 9-608(a)(1)(A) or
9-615(a)(1) of the NYUCC, the residue of any proceeds of collection or sale of
the Collateral shall, to the extent actually received in cash, be applied to the
payment of the remaining Secured Obligations in such order or preference as is
provided in the STID, proper allowance and provision being made for any Secured
Obligations not then due or held as additional Collateral. Pledgor shall remain
liable for any deficiency in the payment of the Secured Obligations.

         Section 18.       AMOUNTS DUE HEREUNDER. Until paid, all amounts
due and payable by Pledgor hereunder shall be a debt secured by the Collateral
and shall bear, whether before or after judgment, interest until paid at a rate
per annum set forth in Section 21.09.

         Section 19.       TERMINATION. Secured Party shall, at the cost of
Pledgor, release the Lien and cancel the security constituted by this Agreement
and procure the reassignment (to the extent necessary) to Pledgor of the
Collateral in accordance with the terms and subject to the conditions and
circumstances set out in clause 5.3 and clause 5.4 of the STID and without
recourse to, or any representations or warranty by, Secured Party or any of its
nominees.

         Section 20.       REINSTATEMENT. The obligations of Pledgor
pursuant to this Agreement shall continue to be effective or automatically be
reinstated, as the case may be, if at any time payment of any of the Secured
Obligations is rescinded or otherwise must be restored or returned by Secured
Party upon the insolvency, bankruptcy, dissolution, liquidation or
reorganization of Pledgor or any other obligor or otherwise, all as though such
payment had not been made.

<PAGE>

                                                                              18

         Section 21.       MISCELLANEOUS.

                  21.01.   Notices. Except as otherwise provided herein,
whenever it is provided herein that any notice, demand, request, consent,
approval, declaration or other communication shall or may be given to or served
upon any of the parties by any other party, or whenever any of the parties
desires to give and serve upon any other party any communication with respect to
this Agreement, each such notice, demand, request, consent, approval,
declaration or other communication shall be in writing and shall be given in the
manner and to the address, and deemed received, as provided for in clause 20 of
the STID.

                  21.02.   GOVERNING LAW; CONSENT TO JURISDICTION. THIS
AGREEMENT SHALL BE GOVERNED BY, AND SHALL BE CONSTRUED AND ENFORCED IN
ACCORDANCE WITH, THE INTERNAL LAWS OF THE STATE OF NEW YORK, WITHOUT REGARD TO
CONFLICTS OF LAWS PRINCIPLES (WHICH PRINCIPLES SHALL BE DEEMED TO EXCLUDE
SECTION 5-1401 OF THE NEW YORK GENERAL OBLIGATIONS LAW). Pledgor agrees that any
suit for the enforcement of this Agreement may be brought in the courts of the
State of New York or any federal court sitting therein and consents to the
non-exclusive jurisdiction of such court and to service of process in any such
suit being made upon Pledgor by mail at the address specified set forth below
its name on the signature pages hereof. Pledgor hereby waives any objection that
it may now or hereafter have to the venue of any such suit or any such court or
that such suit is brought in an inconvenient court.

                  21.03.   WAIVER OF JURY TRIAL, ETC. PLEDGOR WAIVES ITS RIGHT
TO A JURY TRIAL WITH RESPECT TO ANY ACTION OR CLAIM ARISING OUT OF ANY
LITIGATION OR DISPUTE DIRECTLY OR INDIRECTLY ARISING OUT OF, UNDER OR IN
CONNECTION WITH THIS AGREEMENT, ANY RIGHTS OR OBLIGATIONS HEREUNDER OR THE
PERFORMANCE OF ANY SUCH RIGHTS OR OBLIGATIONS. Pledgor certifies that neither
Secured Party nor any representative, agent or attorney of Secured Party has
represented, expressly or otherwise, that Secured Party would not, in the event
of litigation, seek to enforce the foregoing waivers and acknowledges that, in
entering into the Indentures and the other Relevant Documents to which Secured
Party is a party, Secured Party is relying upon, among other things, the waivers
and certifications contained in this Section 21.03.

                  21.04.   Counterparts. This Agreement may be executed in two
or more separate counterparts, each of which shall constitute an original and
all of which shall collectively and separately constitute one and the same
agreement.

                  21.05.   Headings. The headings of each section of this
Agreement are for convenience only and shall not define or limit the provisions
thereof.

                  21.06.   No Strict Construction. The parties hereto have
participated jointly in the negotiation and drafting of this Agreement. In the
event an ambiguity or question of intent or interpretation arises, this
Agreement shall be construed as if drafted jointly by the parties hereto and no
presumption or burden of proof shall arise favoring or disfavoring any party by
virtue of the authorship of any provisions of this Agreement.

                  21.07.   Severability. In the event any one or more of the
provisions contained in this Agreement should be held invalid, illegal or
unenforceable in any respect, the validity, legality and enforceability of the
remaining provisions contained herein shall not in any way be affected or
impaired

<PAGE>

                                                                              19

thereby (it being understood that the invalidity of a particular provision in a
particular jurisdiction shall not in and of itself affect the validity of such
provision in any other jurisdiction).

                  21.08.   Survival of Agreement. All covenants, agreements,
representations and warranties made by Pledgor herein and in the certificates or
other instruments prepared or delivered in connection with or pursuant to this
Agreement shall be considered to have been relied upon by Secured Party and
shall survive the execution and delivery of the Indentures, regardless of any
investigation made by Secured Party, and shall continue in full force and effect
until this Agreement shall terminate (or thereafter to the extent provided
herein).

                  21.09.   Fees and Expenses; Taxes; Indemnification.

                           (a)      Pledgor shall, from time to time and
promptly on demand by Secured Party reimburse to Secured Party all costs and
expenses (including legal fees) on a full indemnity basis together with any
applicable VAT incurred by Secured Party (provided that in relation to clause
(i) of this Section 21.09(a), such costs and expenses must be properly incurred)
in connection with:

                                    (i)      the execution, release and
discharge of this Agreement and the Security created or intended to be created
in respect of the Collateral and perfection of the Security Interest
contemplated in this Agreement or in any such documents or forming part of the
Security Interest created or intended to be created in respect of the
Collateral;

                                    (ii)     the actual or contemplated
exercise, preservation and/or enforcement of any of the rights, powers and
remedies of, or the performance of the duties and obligations of, Secured Party,
or any amendment or waiver in respect of this Agreement;

                                    (iii)    the foreclosure of any Collateral;
and

                                    (iv)     the preservation and/or enforcement
of the Security created or intended to be created in respect of the Collateral;

the amount of which costs and expenses shall carry interest from the date of
such demand until so reimbursed at the rate and on the basis set forth in clause
18.4.1 of the STID.

                           (b)      Pledgor shall pay, promptly on demand of
Secured Party all stamp, registration, notarial and other similar Taxes or fees
paid or payable by Secured Party in connection with any action taken or
contemplated by or on behalf of Secured Party for perfecting, enforcing,
releasing, cancelling, reassigning or resolving any doubt concerning, or for any
other purpose in relation to this Agreement, any amendment thereto, any transfer
and/or assignment of the rights and/or obligations under the same or the
Security Interest created or intended to be created in respect of the Collateral
and shall, from time to time, indemnify Secured Party promptly on demand against
any liabilities, costs, claims and expenses resulting from any failure to pay by
Pledgor or any delay by Pledgor in paying any such Taxes or fees.

                           (c)      Clause 19 of the STID is hereby incorporated
herein by this reference with the same effect as though set forth in its
entirety herein, as if Pledgor were "Issuer" under such clause.

<PAGE>

                                                                              20

                           (d)      Any such amounts payable as provided
hereunder shall be additional Secured Obligations secured hereby. The provisions
of this Section 21.09 shall remain operative and in full force and effect
regardless of the termination of this Agreement, the consummation of the
transactions contemplated hereby, the repayment of any of the Notes, the
invalidity or unenforceability of any term or provision of this Agreement or the
STID, or any investigation made by or on behalf of Secured Party. All amounts
due under this Section 21.09 shall be payable on written demand therefor.

                  21.10.   Matters Relating to Secured Party. Each of Clauses
14, 15 and 16 of the STID is hereby incorporated herein by this reference with
the same effect as though set forth in its entirety herein.

                  21.11.   Binding Effect; Several Agreement. This Agreement is
binding upon Pledgor and Secured Party and their respective successors and
permitted assigns, and shall inure to the benefit of Pledgor, Secured Party and
their respective successors and permitted assigns, except that Pledgor shall
have no right to assign or transfer its rights or obligations hereunder or any
interest herein (and any such assignment or transfer shall be void) except as
expressly contemplated by this Agreement or the Indentures. Secured Party may
assign and transfer all or any of its rights and obligations under this
Agreement in accordance with the STID, and Secured Party shall be entitled to
disclose such information concerning the Pledgor and this Agreement as the
Secured Party considers appropriate to any actual or proposed direct or indirect
successor or to any person to whom information may be required to be disclosed
by applicable law.

                  21.12.   Waivers; Amendment.

                           (a)      No failure or delay of Secured Party in
exercising any power or right hereunder shall operate as a waiver thereof, nor
shall any single or partial exercise of any such right or power, or any
abandonment or discontinuance of steps to enforce such a right or power,
preclude any other or further exercise thereof or the exercise of any other
right or power. The rights and remedies of Secured Party hereunder and under the
STID are cumulative and are not exclusive of any rights or remedies that they
would otherwise have. No waiver of any provisions of this Agreement or consent
to any departure by Pledgor therefrom shall in any event be effective unless the
same shall be permitted by paragraph (b) below, and then such waiver or consent
shall be effective only in the specific instance and for the purpose for which
given. No notice to or demand on Pledgor in any case shall entitle Pledgor to
any other or further notice or demand in similar or other circumstances.

                           (b)      Neither this Agreement nor any provision
hereof may be waived, amended or modified except pursuant to an agreement or
agreements in writing entered into by the Secured Party and Pledgor, subject to
any consent required in accordance with the Indentures and the STID.

                   [the rest of this page intentionally blank]

<PAGE>

                                                                              21

IN WITNESS WHEREOF, intending to be legally bound, Pledgor has caused this
Security Agreement to be duly executed as of the date first above written.

MARCONI COMMUNICATIONS NORTH AMERICA INC.

By: T.C.R. SHEPHERD

    Name: T.C.R. SHEPHERD
    Title: ATTORNEY

Address for New York service of process:

Marconi Electronic Systems Holdings Inc.
c/o Marconi Communications, Inc.
333 Pierce Road - Suite 370
Itasca, Illinois 60143 USA
Attention: Patricia Hoffman
Telecopier No.: (630) 285-1514

ACCEPTED AND AGREED:

THE LAW DEBENTURE TRUST CORPORATION p.l.c.

as Secured Party

By: R.D. RANCE

    Name: R.D. RANCE
    Title: DIRECTOR

<PAGE>

                                                                    Exhibit A to
                                                              Security Agreement

                             PERFECTION CERTIFICATE

Reference is made to the Security Agreement dated as of MAY 19th, 2003 (the
"SECURITY AGREEMENT") between Marconi Communications North America Inc., a
corporation (the "GRANTOR") and The Law Debenture Trust Corporation p.l.c. as
Security Trustee (the "SECURED PARTY"). Capitalized terms used herein without
definition shall have the respective meanings assigned to such terms in the
Security Agreement.

The undersigned, the Authorized Signatory of the Grantor, hereby certifies to
the Secured Party as follows:

1. NAME. The exact legal name of the Grantor as that name appears on its
         Certificate of Incorporation is as follows:

         Marconi Communications North America Inc.

         (Source: Uniform Commercial Code ("UCC") Section 9-503(a).)

2. OTHER IDENTIFYING FACTORS.

         (a)      The following is the mailing address of the Grantor:

         c/o Marconi Communications, Inc.

         333 Pierce Road - Suite 370

         Itasca, IL 60143

         (Source: UCC Section 9-516(b)(5)(A).)

         (b)      If different from its mailing address, the Grantor's place of
business or, if the Grantor has more than one place of business, its chief
executive office, is located at the following address:

         Address                        County                             State
         None.
         (Source: UCCSections 9-301(a) and 9-307; former UCCSection 9-103(3),
          9-103(4), 9-401(6).)

         (c)      The following is the type of organization of the Grantor:

         Corporation

                                      C-1

<PAGE>

         (Source: UCC Section 9-516(b)(5)(C).)

         (d)      The following is the jurisdiction of the Grantor's
                  organization:

         Delaware

         (Source: UCC Section 9-516(b)(5)(C).)

         (e)      The following is the Grantor's state-issued organizational
                  identification number:

         2194521

         (Source: UCC Section 9-516(b)(5)(C).)

3. OTHER CURRENT LOCATIONS.

         (a)      The following are all other locations in the United States of
                  America in which the Grantor maintains any books or records
                  relating to any of the Collateral consisting of accounts,
                  instruments, chattel paper, general intangibles or mobile
                  goods:

<TABLE>
<CAPTION>
Address     County      State
-------     ------      -----
<S>         <C>         <C>
None.
</TABLE>

         (Source: UCC Sections 9-301(b) and (c); former UCC Sections 9-103(3),
         9-103(4), 9-401(6).)

         (b)      The following are all other locations in the United States of
                  America where any of the Collateral consisting of inventory or
                  equipment is located:

<TABLE>
<CAPTION>
Address     County      State
-------     ------      -----
<S>         <C>         <C>
None.
</TABLE>

         (Source: UCC Sections 9-301(b) and (c); former UCC Section 9-103(1).)

         (c)               The following are the names and addresses of all
                  persons or entities other than the Grantor, such as lessees,
                  consignees, processors, warehousemen or purchasers of chattel
                  paper, which persons or entities have possession or are
                  intended to have possession of any of the Collateral
                  consisting of instruments, chattel paper, inventory or
                  equipment and the nature of such possession, if the Collateral
                  is held by such person or entity for more than 90 days and has
                  a book or face value, as the case may be, equal to or greater
                  than $5,000,000 (five million dollars):

                                      C-2

<PAGE>

         None.

         (Source: UCC Sections 9-301(b) and (c), 9-312 and 9-313; former UCC
         Sections 9-103(1), 9-103(4), 9-304(2) and 9-304(3); see also former UCC
         Sections 2-326(3), 9-114, 9-305, 9-308 and 9-408.)

4. INTELLECTUAL PROPERTY. Attached hereto as Schedule 4A is a schedule setting
         forth all of the Grantor's Patents, Patent Licenses, Trademarks and
         Trademark Licenses, including the registration number and the
         expiration date of each Patent, Patent License, Trademark and Trademark
         License owned by the Grantor. Attached hereto as Schedule 4B is a
         schedule setting forth all of the Grantor's Copyrights and Copyright
         Licenses, including the registration number and the expiration date of
         each Copyright or Copyright License owned by the Grantor.

5. UNUSUAL TRANSACTIONS. Except for those purchases, acquisitions and other
         transactions described on Schedule 3 or on Schedule 8 attached hereto,
         all of the Collateral has been originated by the Grantor in the
         ordinary course of the Grantor's business or consists of goods that
         have been acquired by the Grantor in the ordinary course from a person
         in the business of selling goods of that kind.

         None.

         (Source: UCC Sections 9-102(a)(64), 9-203(f), 9-301(b), 9-315(a) and
         9-316; former UCC Sections1-201(9), 9-306(2) and 9-402(7) (third
         sentence); see also former UCC Section 9-301(1)(c).)

6. UCC FILINGS. Attached hereto as Schedule 6 is a copy of financing statement
         filed or to be filed in the central UCC filing office in the
         jurisdiction identified in Section 2(d) and in each real estate
         recording office referred to on Schedule 6 hereto.

7. SCHEDULE OF FILING. Attached hereto as Schedule 7 is a schedule setting forth
         filing information with respect to the filings described in Section 7.

8. STOCK OWNERSHIP AND OTHER EQUITY INTERESTS. Attached hereto as Schedule 8 is
         a true and correct list of each equity investment of the Grantor.

9. DEBT INSTRUMENTS. Attached hereto as Schedule 9 is a true and correct list of
         all promissory notes and other evidence of indebtedness held by the
         Grantor, including all intercompany notes, that have a book or face
         value, as the case may be, equal to or greater than $5,000,000 (five
         million dollars), and additionally for letters of credit, with a term
         of 90 days or longer.

                                      C-3

<PAGE>

IN WITNESS WHEREOF, I have hereunto signed this Certificate on MAY 19th, 2003.

         T.C.R. SHEPHERD
                Name:  T.C.R. SHEPHERD
                Title:  ATTORNEY

                                      C-4

<PAGE>

                                   SCHEDULE 4A

                                      None.

                                      C-5

<PAGE>

                                   SCHEDULE 4B

                                      None.

                                      C-6

<PAGE>

                                   SCHEDULE 5

                                      None.

                                      C-7

<PAGE>

                                   SCHEDULE 6

                                      None.

                                      C-8

<PAGE>

                                   SCHEDULE 7

                                      None.

                                      C-9

<PAGE>

                                   SCHEDULE 8

         Shares in:

         FS Finance Corp.

         Membership interest in:

         Marconi Holdings, LLC

                                      C-10

<PAGE>

                                   SCHEDULE 9

                                      None.

                                      C-11

<PAGE>

                                                                    EXHIBIT B TO
                                                              SECURITY AGREEMENT

                        SUPPLEMENT TO SECURITY AGREEMENT

                                  (COPYRIGHTS)

WHEREAS, MARCONI COMMUNICATIONS NORTH AMERICA INC., a Delaware corporation
(herein referred to as "PLEDGOR"), having an address at c/o Marconi
Communications, Inc., 333 Pierce Road - Suite 370, Itasca, IL 60143, has
adopted, used and is using the copyrights listed on the annexed Schedule 1-A,
which copyrights are registered in the United States Copyright Office (the
"COPYRIGHTS");

WHEREAS, the Pledgor has entered into a Security Agreement dated as of May 19,
2003 (said Security Agreement, as it may hereafter be amended or otherwise
modified from time to time being the "SECURITY AGREEMENT", the terms defined
therein and not otherwise defined herein being used herein as therein defined)
in favor of the Secured Party; and

WHEREAS, pursuant to the Security Agreement, the Pledgor has granted to Secured
Party a security interest in all right, title and interest of the Pledgor in and
to the Copyrights, and the registrations and recordings thereof in the United
States Copyright Office or any other country or any political subdivision
thereof, all whether now or hereafter owned or licensable by the Pledgor and all
extensions or renewals thereof and all Copyright Licenses, and all proceeds of
all of the foregoing, including, without limitation, any claims by the Pledgor
against third parties for infringement thereof (the "COLLATERAL"), to secure the
payment and performance of the Secured Obligations.

NOW, THEREFORE, for good and valuable consideration, receipt of which is hereby
acknowledged, the Pledgor does hereby further confirm, and put on the public
record, its grant to Secured Party of a security interest in and mortgage on the
Collateral to secure the prompt payment and performance of the Secured
Obligations.

The Pledgor does hereby further acknowledge and affirm that the rights and
remedies of Secured Party with respect to the assignment of and grant of a
security interest in the Collateral made hereby are more fully set forth in the
Security Agreement, the terms and provisions of which are hereby incorporated
herein by reference as if fully set forth herein.

Secured Party's address is 5th Floor, 100 Wood Street, London, EC2V 7EX, United
Kingdom.

                                      C-12

<PAGE>

IN WITNESS WHEREOF, the Pledgor has duly executed or caused this Agreement to be
duly executed as of [     ].

MARCONI COMMUNICATIONS NORTH AMERICA INC.

By: ____________________________________________
    Name:
    Title:

                                      C-13

<PAGE>

STATE OF                   )

                           ) SS:

COUNTY OF                  )

On this ____ day of __________, ____, before me personally appeared
__________________, to me known, who, being by me duly sworn, did depose and say
that he/she resides at _________________________________________ and that he/she
is _______________ of Pledgor; that he/she knows the seal of said corporation;
that the seal affixed to said instrument is such corporate seal; that it was
affixed pursuant to authority of the Board of Directors of said corporation and
that he/she signed his/her name thereto in his/her capacity as an authorized
officer of said corporation pursuant to such authority.

                                                   ____________________________

                                                           Notary Public

                                      C-14

<PAGE>

                                                                 SCHEDULE 1-A TO
                                                SUPPLEMENT TO SECURITY AGREEMENT

                                  (COPYRIGHTS)

<TABLE>
<CAPTION>
  COPYRIGHT                    REGISTRATION DATE             REGISTRATION NO.
-------------------        ------------------------       ----------------------
<S>                        <C>                            <C>
</TABLE>

                                      C-15

<PAGE>

                                                                    EXHIBIT C TO
                                                              SECURITY AGREEMENT

                        SUPPLEMENT TO SECURITY AGREEMENT

                                    (PATENTS)

WHEREAS, MARCONI COMMUNICATIONS NORTH AMERICA INC., a Delaware corporation
(herein referred to as "PLEDGOR"), having an address at c/o Marconi
Communications, Inc., 333 Pierce Road - Suite 370, Itasca, IL 60143, owns the
letters patent, and/or applications for letters patent, of the United States of
America, more particularly described on Schedule 1-A annexed hereto as part
hereof (the "PATENTS");

WHEREAS, the Pledgor has entered into a Security Agreement dated as of May 19,
2003 (said Security Agreement, as it may hereafter be amended or otherwise
modified from time to time being the "SECURITY AGREEMENT", the terms defined
therein and not otherwise defined herein being used herein as therein defined)
in favor of the Secured Party; and

WHEREAS, pursuant to the Security Agreement, the Pledgor has granted to Secured
Party a security interest in all right, title and interest of Pledgor in and to
the Patents, together with all registrations and recordings thereof, including,
without limitation, applications, registrations and recordings in the United
States Patent and Trademark Office or in any similar office or agency of the
United States, any State thereof or any other country or any political
subdivision thereof, all whether now or hereafter owned or licensable by
Pledgor, and all reissues, continuations, continuations-in-part, term
restorations or extensions thereof, all Patent Licenses and all proceeds of all
of the foregoing, including, without limitation, any claims by Pledgor against
third parties for infringement thereof for the full term of the Patents (the
"COLLATERAL"), to secure the prompt payment and performance of the Secured
Obligations.

NOW, THEREFORE, for good and valuable consideration, receipt of which is hereby
acknowledged, the Pledgor does hereby further confirm, and put on the public
record, its grant to Secured Party of a security interest in and mortgage on the
Collateral to secure the prompt payment and performance of the Secured
Obligations.

The Pledgor does hereby further acknowledge and affirm that the rights and
remedies of Secured Party with respect to the assignment of and grant of a
security interest in the Collateral made hereby are more fully set forth in the
Security Agreement, the terms and provisions of which are hereby incorporated
herein by reference as if fully set forth herein.

Secured Party's address is 5th Floor, 100 Wood Street, London, EC2V 7EX, United
Kingdom.

                                      D-1

<PAGE>

IN WITNESS WHEREOF, the Pledgor has duly executed or caused this Supplement to
Security Agreement to be duly executed as of [     ].

MARCONI COMMUNICATIONS NORTH AMERICA INC.

By: ____________________________________________
    Name:
    Title:

                                      D-2

<PAGE>

STATE OF                   )

                           ) SS:

COUNTY OF                  )

On this ____ day of ____________, before me personally appeared
________________, to me known, who, being by me duly sworn, did depose and say
that he/she resides at _________________________________ and that he/she is
_______________ of Pledgor; that he/she knows the seal of said corporation; that
the seal affixed to said instrument is such corporate seal; that it was affixed
pursuant to authority of the Board of Directors of said corporation and that
he/she signed his/her name thereto in his/her capacity as an authorized officer
of said corporation pursuant to such authority.

                                                    ____________________________

                                                           Notary Public

                                      D-3

<PAGE>

                                                                 SCHEDULE 1-A TO
                                                SUPPLEMENT TO SECURITY AGREEMENT

                                    (PATENTS)

<TABLE>
<CAPTION>
                                     DATE FILED                 SERIAL NO. OR
        TITLE                        OR GRANTED                   PATENT NO.
-----------------------       ----------------------       ---------------------
<S>                           <C>                          <C>
</TABLE>

                                      D-4

<PAGE>

                                                                    EXHIBIT D TO
                                                              SECURITY AGREEMENT

                        SUPPLEMENT TO SECURITY AGREEMENT

                                  (TRADEMARKS)

WHEREAS, MARCONI COMMUNICATIONS NORTH AMERICA INC., a Delaware corporation
(herein referred to as "PLEDGOR"), having an address at c/o Marconi
Communications, Inc., 333 Pierce Road - Suite 370, Itasca, IL 60143, (1) has
adopted, used and is using, or (2) has intended to use and filed an application
indicating that intention, but has not yet filed an allegation of use under
Section l(c) or l(d) of the Trademark Act, or (3) has filed an application based
on an intention to use and has since used and has filed an allegation of use
under Section l(c) or l(d) of the Trademark Act, the trademarks, trade names,
trade styles and service marks listed on the annexed Schedule 1-A, which
trademarks, trade names, trade styles and service marks are registered in the
United States Patent and Trademark Office (the "TRADEMARKS"); and

WHEREAS, the Pledgor has entered into a Security Agreement dated as of May 19,
2003 (said Security Agreement, as it may hereafter be amended or otherwise
modified from time to time being the "SECURITY AGREEMENT", the terms defined
therein and not otherwise defined herein being used herein as therein defined)
in favor of the Secured Party; and

WHEREAS, pursuant to the Security Agreement, the Pledgor has granted to Secured
Party a security interest in all right, title and interest of the Pledgor in and
to the Trademarks, together with all prints and labels on which said Trademarks
have appeared or appear, designs and general intangibles of like nature, now
existing or hereafter adopted or acquired, and the goodwill of the business
symbolized by the Trademarks and the applications, registrations and recordings
in the United States Patent and Trademark Office or in any similar office or
agency of the United States of America, any State thereof, or any other country
or any political subdivision thereof, all whether now or hereafter owned or
licensable by Pledgor, and all reissues, extensions or renewals thereof, all
Trademark Licenses and all proceeds of all of the foregoing, including, without
limitation, any claims by Pledgor against third parties for infringement thereof
(the "COLLATERAL"), to secure the payment and performance of the Secured
Obligations.

NOW, THEREFORE, for good and valuable consideration, receipt of which is hereby
acknowledged, the Pledgor does hereby further confirm, and put on the public
record, its grant to Secured Party of a security interest in and mortgage on the
Collateral to secure the prompt payment and performance of the Secured
Obligations.

The Pledgor does hereby further acknowledge and affirm that the rights and
remedies of Secured Party with respect to the grant of, security interest in and
mortgage on the Collateral made hereby are more fully set forth in the Security
Agreement; the terms and provisions of which are hereby incorporated herein by
reference as if fully set forth herein.

Secured Party's address is 5th Floor, 100 Wood Street, London, EC2V 7EX, United
Kingdom.

                                      E-1

<PAGE>

IN WITNESS WHEREOF, the Pledgor has duly executed or caused this Supplement to
the Security Agreement to be duly executed as of [     ].

MARCONI COMMUNICATIONS NORTH AMERICA INC.

By: ____________________________________________
    Name:
    Title:

                                      E-2

<PAGE>

STATE OF                   )

                           ) SS:

COUNTY OF                  )

On this ____ day of _________, ____, before me personally appeared
___________________, to me known, who, being by me duly sworn, did depose and
say that he/she resides at _________________________________________ and that
he/she is _______________ of Pledgor; that he/she knows the seal of said
corporation; that the seal affixed to said instrument is such corporate seal;
that it was affixed pursuant to authority of the Board of Directors of said
corporation and that he/she signed his/her name thereto in his/her capacity as
an authorized officer of said corporation pursuant to such authority.

                                                    ____________________________

                                                           Notary Public

                                      E-3

<PAGE>

                                                                 SCHEDULE 1-A TO
                                                SUPPLEMENT TO SECURITY AGREEMENT

                                   TRADEMARKS

<TABLE>
<CAPTION>
                               APPLICATION OR       APPLICATION SERIAL NO. OR
    TRADEMARK                 REGISTRATION DATE          REGISTRATION NO.
-----------------------     ----------------------  -------------------------
<S>                         <C>                     <C>
</TABLE>

                                      E-4