<PAGE>

                                                                    EXHIBIT 4.62

CLIFFORD                                                          CONFORMED COPY
CHANCE
PUNDER

                     MARCONI COMMUNICATIONS REAL ESTATE GMBH

                                   AS ASSIGNOR

                                       AND

                   THE LAW DEBENTURE TRUST CORPORATION p.l.c.

                               AS SECURITY TRUSTEE

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                      SHAREHOLDER LOAN ASSIGNMENT AGREEMENT

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<PAGE>

                                    CONTENTS
<TABLE>
<CAPTION>
CLAUSE                                                                                                  PAGE
<S>                                                                                                     <C>
1.       Definitions and Languages.....................................................................   2

2.       Secured Obligations...........................................................................   3

3.       Assignment....................................................................................   3

4.       Information...................................................................................   3

5.       Transfer of Ancillary Rights..................................................................   4

6.       Collection of Receivables by the Assignor.....................................................   4

7.       Right to Realisation upon Enforcement Event...................................................   5

8.       Limitation of Security........................................................................   5

9.       Further Assurance.............................................................................   7

10.      Release (Sicherheitenfreigabe)................................................................   7

11.      Bookkeeping and Data-Processing...............................................................   8

12.      Expenses, Costs and Taxes.....................................................................   9

13.      Partial Invalidity, Waiver...................................................................   10

14.      Amendments; Waiver...........................................................................   10

15.      Notices and their Language...................................................................   10

16.      Applicable Law, Jurisdiction.................................................................   12

18.      Effectiveness................................................................................   13

19.      Counterparts.................................................................................   13
</TABLE>

<PAGE>

THIS AGREEMENT is made the 16th day of May 2003

BETWEEN:

1.       Marconi Communications Real Estate GmbH, a limited liability company
         organised under the laws of the Federal Republic of Germany, having its
         business address at GerberstraBe 33, D-71522 Backnang, which is
         registered in the commercial register (Handelsregister) of the local
         court (Amtsgericht) of Backnang under HRB 1561 (the "ASSIGNOR"); and

2.       The Law Debenture Trust Corporation p.l.c., having its business address
         at Fifth Floor, 100 Wood Street, London, EC2V 7EX, England in its
         capacity as security trustee under the Relevant Documents (the
         "SECURITY TRUSTEE").

WHEREAS:

(A)      Marconi Corporation p.l.c. (the "ISSUER") has agreed to issue the
         following notes:

         (i)      USD equivalent of GBP 450,000,000 senior secured notes due
                  2008;

         (ii)     USD 300,000,000 plus USD equivalent of GBP 117,270,000 of
                  junior secured notes due 2008;

                  the notes under (i) being documented in a senior note
                  indenture dated on or about 19 May 2003 between, inter alios,
                  the Issuer and Law Debenture Trust Company of New York as
                  Senior Note Trustee and the notes under (ii) being documented
                  in a junior note indenture dated on or about 19 May 2003
                  between, inter alios, the Issuer and JPMorgan Chase Bank as
                  Junior Note Trustee (together the "INDENTURES").

(B)      The security created by or pursuant to this Agreement is to be granted
         to and administered by the Security Trustee for itself and as trustee
         of the Secured Creditors pursuant to the relevant provisions of a
         security trust and intercreditor deed dated on or about 19 May 2003
         between, inter alios, the Issuer, Law Debenture Trust Company of New
         York as Senior Note Trustee, JPMorgan Chase Bank as Junior Note
         Trustee, the Security Trustee and the Obligors (as defined therein
         including the Assignor) as amended from time to time (the "SECURITY
         TRUST AND INTERCREDITOR DEED").

(C)      The Assignor has agreed to assign the Receivables (as defined below) as
         security for the payment and discharge of the Secured Obligations (as
         defined below) subject to the terms and conditions set out herein.

                                     - 1 -

<PAGE>

NOW, IT IS AGREED as follows:

1.       DEFINITIONS AND LANGUAGES

1.1      In this Agreement:

         "AUTHORIZATION" has the meaning given to it in Clause 6.

         "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 the
         purposes of this definition of "continuing" the expression "Secured
         Obligations" shall have the same meaning as in the Security Trust and
         Intercreditor Deed.

         "RECEIVABLES" means all present and future rights and claims owing to
         the Assignor and originating from shareholders loans, including but not
         limited to those specified in Schedule 1.

         "SECURED OBLIGATIONS" has the meaning given to it under clause 2.

         "SECURITY TRUST AND INTERCREDITOR DEED" has the meaning given to it in
         Clause (B) of the recitals.

1.2      Unless otherwise defined herein or unless the context requires,
         capitalised terms shall have the same meaning as ascribed thereto in
         the Security Trust and Intercreditor Deed.

1.3      This Agreement is made in the English language. For the avoidance of
         doubt, the English language version of this Agreement shall prevail
         over any translation of this Agreement. However, where a German
         translation of a word or phrase appears in the text of this Agreement,
         the German translation of such word or phrase shall prevail.

                                     - 2 -

<PAGE>

1.4      The parties hereto each acknowledge that the Security Trustee, when
         acting hereunder, shall, to the extent permitted under the laws of
         Germany, be acting in accordance with and subject to the terms of the
         Security Trust and Intercreditor Deed.

2.       SECURED OBLIGATIONS

         The assignment hereunder (the "ASSIGNMENT") is constituted in order to
         secure together with other security granted by the Assignor the prompt
         and complete satisfaction of any and all obligations (present and
         future, actual and contingent) which are (or are expressed to be) or
         become owing by the Assignor to the Secured Creditors or any of them
         (including any future assignee or transferee of any of the Secured
         Creditors by way of transfer or assignment (including by way of
         assumption of debt (Vertragsubernahme)) under the Relevant Documents
         (including, but not limited to the parallel obligations of the Assignor
         pursuant to clause 3 of the Security Trust and Intercreditor Deed to
         pay to the Security Trustee sums equal to the sums owed by the Assignor
         to the Secured Creditors or any of them) (the "SECURED Obligations") up
         to an aggregate amount of EUR 30 million.

3.       ASSIGNMENT

3.1      The Assignor hereby assigns the Receivables to the Security Trustee in
         its capacity as Security Trustee for the benefit of the Secured
         Creditors.

3.2      The Security Trustee hereby accepts the assignment of the Receivables.

3.3      Subject to clause 3.4 below the existing Receivables shall pass over to
         the Security Trustee on execution of this Agreement, and any future
         Receivables shall pass over to the Security Trustee at the date such
         Receivables arise.

3.4      Notwithstanding the other provisions in this Clause 3 the assignment of
         all Receivables shall be effective only if and upon the condition
         (aufschiebende Bedingung) that the aggregate amount of Receivables owed
         to the Assignor exceeds GBP 20 million or its equivalent in any other
         currency.

4.       INFORMATION

4.1      The Assignor shall, upon request of the Security Trustee deliver to the
         Security Trustee such further information on the Receivables as deemed
         necessary by the Security Trustee.

                                     - 3 -

<PAGE>

4.2      The Assignor undertakes to provide the Security Trustee promptly at its
         request with all information and documents which are necessary for
         perfecting and/or enforcing the security created hereby.

5.       TRANSFER OF ANCILLARY RIGHTS

5.1      Together with all the Receivables assigned and transferred in
         accordance with this Agreement, all securities, collateral and all
         ancillary rights pertaining thereto, as well as all rights resulting
         from the underlying agreements (hereinafter together with the
         Receivables referred to as the "COLLATERAL"), are hereby transferred to
         and assigned to the Security Trustee, to the extent such rights are not
         automatically transferred to the Security Trustee pursuant to Section
         401 of the German Civil Code (Burgerliches Gesetzbuch). The Assignor's
         claims to demand repossession against the direct possessor are assigned
         to the Security Trustee at the same time.

5.2      If the Assignor is in direct possession of the Collateral, the delivery
         of such Collateral shall be substituted by the Assignor holding the
         Collateral in gratuitous custody for the Security Trustee.

6.       COLLECTION OF RECEIVABLES BY THE ASSIGNOR

         The Security Trustee authorises the Assignor to collect the Receivables
         (such authorization hereinafter referred to as the "AUTHORIZATION") to
         the extent not expressly prohibited by the terms of the Indentures. The
         Security Trustee may revoke the Authorization upon the occurrence of an
         Insolvency Event of Default and the Security Trustee shall revoke the
         Authorization if the Security Trustee has been so instructed pursuant
         to the Security Trust and Intercreditor Deed upon or at any time after
         the occurrence of an Event of Default which is continuing, whereupon
         the Assignor may continue to collect the Receivables but shall promptly
         surrender the proceeds to the Security Trustee. Until the requirements
         set out in Clause 7.1 are met the Security Trustee shall treat such
         proceeds as additional collateral for the Secured Obligations. To the
         extent that the Authorization is revoked, the Security Trustee may
         request that copies of all documents relating to the Receivables be
         handed over to it and the Assignor hereby agrees to comply with any
         such request. For the avoidance of doubt nothing in this Clause 6 shall
         restrict the right of the Security Trustee to enforce its rights under
         Clause 7 if the requirements set out in Clause 7.1 are met.

                                     - 4 -

<PAGE>

7.       RIGHT TO REALISATION UPON ENFORCEMENT EVENT

7.1      At any time after the occurrence of an Enforcement Event which is
         continuing and the Security Trustee (acting on instructions received
         pursuant to the terms of the Security Trust and Intercreditor Deed)
         giving notice to the Issuer thereof and if any of the Secured
         Obligations became due and payable the Security Trustee shall, in its
         discretion, be entitled to arrange for the collection or disposal of
         Receivables for and on behalf of the Secured Creditors in accordance
         with the provisions of this Clause 7.

7.2      To the extent that the Authorization is revoked, the Security Trustee
         may request that originals of all documents relating to the Receivables
         be handed over to it and the Assignor hereby agrees to comply with any
         such request.

7.3      The Security Trustee shall realise all or part of the Collateral to the
         extent necessary to satisfy any outstanding Secured Obligations by
         collecting all or part of the Receivables, it being understood that the
         Security Trustee shall apply the proceeds of such realisation towards
         the Secured Obligations in accordance with and subject to the terms of
         the Security Trust and Intercreditor Deed.

7.4      The Security Trustee may request the Assignor to collect the
         Receivables for and on behalf of the Secured Creditors and the Assignor
         shall promptly comply with such request.

7.5      If the Security Trustee collects any Receivables pursuant to this
         Clause 7, it may take all measures and enter into all agreements with
         the debtors of the Receivables which it considers to be expedient.

7.6      With respect to the realisation of the Collateral, the Security Trustee
         will take into consideration the legitimate interest of the Assignor.

8.       LIMITATION OF SECURITY

8.1      The right to enforce the security interests created hereunder shall, to
         the extent that the Secured Obligations represent those of an
         affiliated company (verbundenes Unternehmen) within the meaning of
         Section 15 et seq. of the German Stock Corporation Act (Aktiengesetz)
         of the Assignor (other than any of the Assignor's subsidiaries), at all
         times be limited to an amount equal to the Assignor's assets (the
         calculation of which shall take into account the captions reflected in
         Section 266 sub-section (2) A, B and C of the German Commercial Code
         (Handelsgesetzbuch)) less the sum of (A) the Assignor's liabilities
         (the calculation of which shall take into account the captions
         reflected in Section 266 subsection (3) B, C and D of the

                                     - 5 -

<PAGE>

         count the captions reflected in Section 266 subsection (3)B, C and D of
         the German Commercial Code), and (B) the stated share capital
         (Stammkapital) of the Assignor (the "NET ASSETS").

8.2      The Assignor shall realise, to the extent legally permitted and, in
         respect of the Assignor, commercially justifiable, in a situation where
         the Assignor does not have sufficient Net Assets to maintain its
         registered share capital, any and all of its assets that are shown in
         the balance sheet with a book value (Buchwert) that is significantly
         lower than the market value of the assets if the asset is not necessary
         for the Assignor's business (betriebsnotwendig).

8.3      The Security Trustee shall enforce any security interest created
         hereunder against the Assignor in accordance with the following
         procedure:

                  (i)      The Assignor shall, following a notification by the
                           Security Trustee to the Assignor that an Enforcement
                           Event has occurred and that the Security Trustee
                           intends to enforce the security interests created
                           hereunder, deliver to the Security Trustee within
                           sixty days of such notification an auditors'
                           determination from a firm of auditors of
                           international standard and reputation (the "AUDITORS'
                           DETERMINATION") stating the value of the Net Assets,
                           i.e., the amounts which may be claimed against the
                           Assignor under the security interests created
                           hereunder having regard to Sections 30 and 31 of the
                           German Limited Liability Companies Act.

                  (ii)     The Auditors' Determination, i.e., the amount which
                           may be claimed against the Assignor under the
                           security interests created hereunder, having regard
                           to Section 30 and 31 of the German Limited Liability
                           Companies Act, shall take into account the generally
                           accepted accounting principles applicable from time
                           to time in Germany (GAAP) and be based on the same
                           principles that were applied when establishing the
                           previous year's balance sheet.

                  (iii)    The amount specified in the relevant Auditors'
                           Determination pertaining to the Assignor shall be
                           up-to-date and in any event such Auditors'
                           Determination shall have been prepared as of a date
                           no earlier than 15 business days prior to the date of
                           notification by the Security Trustee to the Assignor
                           that it intends to enforce the security interests
                           created hereunder.

                                     - 6 -

<PAGE>

                  (iv)     If the Assignor fails to deliver the Auditors'
                           Determination to the Security Trustee within the
                           sixty day period stated in (i) above, the Security
                           Trustee shall be entitled to enforce the security
                           interests created hereunder against the Assignor
                           without limitation.

9.       FURTHER ASSURANCE

         Insofar as additional documents, declarations or actions (including
         making all filings and registrations) are necessary for the creation,
         perfection, protection or maintenance of the security interests created
         (or purported to be created) hereunder (or any of them) in favour of
         the Security Trustee or for the exercise of all rights, powers and
         remedies of the Security Trustee provided by or pursuant to this
         Agreement or by law or to facilitate the realisation of the security
         interests created (or purported to be created) hereunder (or any of
         them), the Assignor shall at the Security Trustee's request enter into
         or provide such documents, make such declarations and/or undertake such
         actions at the Assignor's cost and expense.

10.      RELEASE (SICHERHEITENFREIGABE)

10.1     Upon complete and irrevocable satisfaction of the Secured Obligations,
         the Security Trustee shall (in accordance with the terms and subject to
         the conditions and circumstances set out in the Security Trust and
         Intercreditor Deed and without recourse to, or any representations or
         warranty by, the Security Trustee or any of its nominees) at the cost
         and expense of the Assignor reassign and/or transfer, as the case may
         require, to the Assignor, which shall accept such re-assignment and/or
         re-transfer, the Collateral and surrender the excess proceeds, if any,
         resulting from any realisation thereof. The Security Trustee will,
         however, transfer any Receivables to a third person if so required by
         law.

10.2     At any time when the total value of the aggregate security granted by
         the Assignor to secure the Secured Obligations (the "SECURITY") which
         can be expected to be realised in the event of an enforcement of the
         Security (realisierbarer Wert) exceeds 110% of the Secured Obligations
         (the "LIMIT") not only temporarily, the Security Trustee shall (in
         accordance with the terms and subject to the conditions and
         circumstances set out in the Security Trust and Intercreditor Deed and
         without recourse to, or any representations or warranty by, the
         Security Trustee or any of its nominees) on demand of the Assignor
         release such part of the Security (Sicherheitenfreigabe) as the
         Security Trustee may in its discretion determine so as to reduce the
         realisable value of the Security to the Limit.

                                     - 7 -

<PAGE>

11.      BOOKKEEPING AND DATA-PROCESSING

11.1     If proof or documents which are necessary to identify the Collateral
         have been handed over by the Assignor to a third party (in particular a
         bookkeeping firm or a tax consultant) the Assignor hereby transfers (on
         condition of (aufschiebende Bedingung) (i) the occurrence of an
         Insolvency Event of Default or (ii) notice by the Security Trustee if
         the Security Trustee has been so instructed pursuant to the Security
         Trust and Intercreditor Deed upon or at any time after the occurrence
         of an Event of Default which is continuing)to the Security Trustee, who
         accepts such transfer, its right to demand from such third party the
         return of the information and documents. The Assignor hereby undertakes
         to instruct the third party upon such transfer to provide the Security
         Trustee upon its demand with such information and documents which are
         necessary to perfect and/or enforce the security created hereby.

11.2     If details concerning the Collateral or any part thereof have been
         stored in an electronic data-processing system, then, upon the
         occurrence of an Insolvency Event of Default or upon request by the
         Security Trustee if the Security Trustee has been so instructed
         pursuant to the Security Trust and Intercreditor Deed upon or at any
         time after the occurrence of an Event of Default which is continuing,
         the Assignor shall allow the Security Trustee access to the computer,
         including the peripheral equipment and all data concerning the
         Collateral or such part thereof. Moreover, software operators shall be
         made available insofar as so required, and any assistance required
         shall be provided to the Security Trustee. If a third party handles the
         electronic processing of data, the Assignor hereby transfers (on
         condition of (aufschiebende Bedingung) (i) the occurrence of an
         Insolvency Event of Default or (ii) notice by the Security Trustee if
         the Security Trustee has been so instructed pursuant to the Security
         Trust and Intercreditor Deed upon or at any time after the occurrence
         of an Event of Default which is continuing) to the Security Trustee,
         who accepts this transfer, all rights against such third party relating
         to these services. The Assignor hereby undertakes to instruct the third
         party upon such transfer to handle the processing of data for the
         Security Trustee upon its demand as it did for the Assignor.

11.3     After transfer of the rights to the Security Trustee as contemplated in
         Clauses 11.1 and 11.2, the Security Trustee shall promptly upon request
         of the Assignor or after the Security Trustee receiving instructions
         pursuant to the Security Trust and Intercreditor Deed instruct the
         third party to provide the Assignor with such services and information
         as necessary for the Assignor in connection with the preparation and
         delivery of the Auditors' Determination.

                                     - 8 -

<PAGE>

12.      EXPENSES, COSTS AND TAXES

12.1     EXPENSES

         The Assignor shall, from time to time and promptly on demand by the
         Security Trustee reimburse to the Security Trustee all costs and
         expenses (including legal fees) on a full indemnity basis together with
         any applicable VAT incurred by the Security Trustee and any Delegate
         (provided that in relation to sub-clause (i) of this Clause 12, 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 the
                           perfection of the security contemplated in this
                           Agreement or in any such documents or forming part of
                           the security 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, the Security Trustee or any Delegate,
                           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,

                  which shall carry interest (before and after any judgment and
                  to the extent interest at a default rate is not otherwise
                  being paid on such sum) from the date of such demand until so
                  reimbursed calculated on a daily basis at the rate determined
                  in accordance with the provisions of clause 18.4 (Interest on
                  Demands) of the Security Trust and Intercreditor Deed.

12.2     TAXES

         The Assignor shall pay, promptly on demand of the Security Trustee all
         stamp, registration, notarial and other similar Taxes or fees paid or
         payable by the Security Trustee in connection with any action taken or
         contemplated by or on behalf of the Security Trustee 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 created or intended to be
         created in respect of the Collateral and shall, from time to time,
         indemnify the Security Trustee

                                     - 9 -

<PAGE>

         promptly on demand against any liabilities, costs, claims and expenses
         resulting from any failure to pay by the Assignor or any delay by the
         Assignor in paying any such Taxes or fees.

13.      PARTIAL INVALIDITY, WAIVER

13.1     If at any time, any one or more of the provisions hereof is or becomes
         invalid, illegal or unenforceable in any respect under the law of any
         jurisdiction, that provision shall as to that jurisdiction be
         ineffective to the extent necessary without affecting or impairing the
         validity, legality and enforceability of the remaining provisions of
         this Agreement or of such provisions in any other jurisdiction. The
         invalid or unenforceable provision shall be deemed replaced by a valid,
         legal and enforceable provision which comes as close as possible to the
         orginal intent of the parties as to the invalid, illegal or
         unenforceable provision. This shall apply analogously in the case of
         gaps.

13.2     No failure to exercise, nor any delay in exercising, on the part of the
         Security Trustee, any right or remedy hereunder shall operate as a
         waiver thereof, nor shall any single or partial exercise of any right
         or remedy prevent any further or other exercise thereof or the exercise
         of any other right or remedy. The rights and remedies provided
         hereunder are cumulative and not exclusive of any rights or remedies
         provided by law.

14.      AMENDMENTS; WAIVER

         This Agreement may be amended, modified or waived only in writing in an
         agreement signed by the Security Trustee. This also applies to this
         Clause 14.

15.      NOTICES AND THEIR LANGUAGE

15.1     Each communication under or in connection with this Agreement shall be
         made in writing and, unless otherwise stated, may be made by fax or
         letter.

15.2     Any communication or document to be made or delivered under or in
         connection with this Agreement shall be made or delivered to the
         following addresses or fax numbers (and for the attention of the
         department or officer noted):

                                     - 10 -

<PAGE>

         for the Assignor:               Marconi Communications Real Estate GmbH
                                         Address:   GerberstraBe 33
                                                    D-71522 Backnang

                                         Fax: 07191 13 2419
                                         Attention: Hans-Werner Altermann
                                                    Legal Advisor

         for the Security Trustee: The Law Debenture Trust Corporation p.l.c.

                                         Address:   Fifth Floor
                                                    100 Wood Street
                                                    London EC2V 7EX
                                                    England

                                         Fax:       +44 20 7696 5261
                                         Attention: Manager Trust Adminstration

         or to such other address as the recipient may notify or may have
         notified to the other party in writing.

15.3     DELIVERY

15.3.1   Any communication or document made or delivered by one person to
         another under or in connection with this Agreement will only be
         effective:

         (a)      if by way of fax, when received in legible form; or

         (b)      if by way of letter, when it has been left at the address
                  specified in Clause 15.2 above or five Business Days after
                  being deposited in the post postage prepaid in an envelope
                  addressed to the addressee at that address,

         and, if a particular department or officer is specified as part of that
         address, if addressed to that department or officer.

15.3.2   Notwithstanding the provisions of sub-clause 15.3.1 (b) above, any
         communication or document to be made or delivered to the Security
         Trustee will be effective only when actually received by the Security
         Trustee and then only if it is expressly marked for the attention of
         the department or officer identified in Clause 15.2 (or any substitute
         department or officer as such person shall specify for this purpose).

                                     - 11 -

<PAGE>

15.4     Any notice given under or connection with this Agreement shall be in
         the English language. All other documents provided under or in
         connection with this Agreement shall be in the English language or, if
         in any other language, accompanied by a translation into English which
         if reasonably requested by the Security Trustee shall be a certified
         translation. In the event of any conflict between the English text and
         the text in any other language, the English text shall prevail unless
         the document is a contractual, statutory or other official document.

16.      APPLICABLE LAW, JURISDICTION

16.1     APPLICABLE LAW

         This Agreement shall be governed by and construed in accordance with
         the laws of the Federal Republic of Germany.

16.2     GERMAN COURTS

         The courts of Frankfurt am Main have exclusive jurisdiction to settle
         any dispute (a "DISPUTE") arising out of or in connection with this
         Agreement (including a dispute regarding the existence, validity or
         termination of this Agreement or the consequences of its nullity).

16.3     CONVENIENT FORUM

         The parties agree that the courts of Frankfurt am Main are the most
         appropriate and convenient courts to settle Disputes between them and,
         accordingly, that they will not argue to the contrary.

16.4     NON-EXCLUSIVE JURISDICTION

         This Clause 16 is for the benefit of the Secured Creditors only. As a
         result it does not prevent any Secured Creditor from taking proceedings
         relating to a Dispute ("PROCEEDINGS") in any other courts with
         jurisdiction. To the extent allowed by law, the Secured Creditors may
         take concurrent Proceedings in any number of jurisdictions.

17.      ASSIGNMENT

         The Security Trustee may assign and transfer all or any of its rights
         and obligations under this Agreement in accordance with the Security
         Trust and Intercreditor Deed. To the extent legally permissible the
         Security Trustee shall be entitled to disclose such information
         concerning the Assignor and this Agreement as the Security Trustee
         considers appropriate to any actual or proposed direct or indirect
         successor or to

                                     - 12 -

<PAGE>

         any person to whom information may be required to be disclosed by any
         applicable law.

18.      EFFECTIVENESS

         This Agreement shall become effective only subject to the condition
         precedent and at the time of the first original issuance of the Senior
         Notes.

19.      COUNTERPARTS

         This Agreement may be executed in any number of counterparts and by
         different parties hereto on separate counterparts each of which, when
         executed and delivered, shall constitute an original, but all the
         counterparts shall together constitute but one and the same instrument.

                                     - 13 -

<PAGE>

                                   SCHEDULE 1

                                SHAREHOLDER LOANS

                                     - 14 -

<PAGE>

                                 SIGNATURE PAGES

THIS SHAREHOLDER LOAN ASSIGNMENT AGREEMENT HAS BEEN ENTERED INTO ON THE DATE
STATED AT THE BEGINNING BY:

MARCONI COMMUNICATIONS REAL ESTATE GmbH

By: MARY SKELLY
    Name:  Mary Skelly
    Title: Attorney

THE LAW DEBENTURE TRUST CORPORATION p.l.c.

By: R. D. RANCE
    Name:  R. D. Rance
    Title: Director

                                     - 15 -