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                                                                  Exhibit 10.24


                              DATED 6 APRIL 2000

                                    BETWEEN

                             COMPLETEL EUROPE N.V.
                                   AS PARENT

                               COMPLETEL S.A.S.
                              AS OBLIGORS' AGENT

                        MEMBERS OF THE COMPLETEL GROUP
                             AS ORIGINAL BORROWERS

                        MEMBERS OF THE COMPLETEL GROUP
                            AS ORIGINAL GUARANTORS

                    GOLDMAN SACHS INTERNATIONAL AND PARIBAS
                               AS LEAD ARRANGERS

                           EUROPEAN INVESTMENT FUND
                              AS RISK PARTICIPANT

                                    PARIBAS
                               AS SECURITY AGENT

                                    PARIBAS
                               AS FACILITY AGENT

                                      AND

                                    OTHERS

                _______________________________________________
                            SUPPLEMENTAL AGREEMENT
                         RELATING TO THE SUSPENSION OF
                             CERTAIN PROVISIONS OF
                              A CREDIT AGREEMENT
                          DATED 6 JANUARY 2000 AND A
                  PARTICIPATION AGREEMENT DATED 17 MARCH 2000
                _______________________________________________
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THIS AGREEMENT is made on 6 April 2000

BETWEEN

(1)  COMPLETEL EUROPE N.V. (the "Parent");

(2)  COMPLETEL S.A.S. in its capacity as the obligors' agent (the "Obligors
     Agent");

(3)  THE COMPANIES listed in Part A of Schedule 1 (The Original Parties) of the
     Credit Agreement (defined below) in their capacity as borrowers (the
     "Original Borrowers");

(4)  THE COMPANIES listed in Part B of Schedule 1 (The Original Parties) of the
     Credit Agreement (defined below) in their capacity as original guarantors
     (the "Original Guarantors");

(5)  GOLDMAN SACHS INTERNATIONAL and PARIBAS as lead arrangers (the "Lead
     Arrangers")

(6)  PARIBAS as facility agent for the Participants (the "Facility Agent");

(7)  PARIBAS as security agent for the Participants (the "Security Agent");

(8)  EUROPEAN INVESTMENT FUND as risk participant (the "EIF"); and

(9)  THE FINANCIAL INSTITUTIONS named in Part C of Schedule 1 (The Original
     Parties) of the Credit Agreement (defined below) in their capacity as Banks
     (the "Banks").

RECITALS

IT IS AGREED as follows.

1.  DEFINITIONS AND INTERPRETATION

1.1 Definitions
    In this Deed:

    "Credit Agreement" means the euro 265,000,000 Credit Agreement dated 6
    January 2000 between the Parent, the Obligors' Agent, the Original
    Borrowers, the Original Guarantors, the Lead Arrangers, the Facility Agent,
    the Security Agent and the Banks defined therein as amended and restated by
    the Supplemental Deed.

    "Effective Date" means the date the Facility Agent receives a notice from
    the Parent stating that the New High Yield Bond is expected to close
    imminently and requesting this Agreement to become effective immediately.

    "Enlarged Business Plan" means the management base case for the Group
    reflecting the utilisation of proceeds of the IPO and the New High Yield
    Bond to be delivered by the Parent to the Facility Agent.
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    "New High Yield Bond" means the, up to, euro 300,000,000 senior notes due
    2010 of the Parent to be issued in April 2000.

    "Restricted Period" shall have the meaning given to such term in sub-clause
    4.1.2 hereunder.

    "Supplemental Deed" means the supplemental deed relating to the Credit
    Agreement and the Subordination, Security Agency and Intercreditor Deed
    dated 17 March 2000.

1.2 Incorporation of Defined Terms
    Terms defined in the Credit Agreement shall, unless otherwise defined
    herein, have the same meaning herein and the principles of construction set
    out in the Credit Agreement shall have effect as if set out in this
    Agreement.

1.3 Clauses
    In this Agreement any reference to a "Clause" or a "Schedule" is, unless the
    context otherwise requires, a reference to a Clause or a Schedule hereof.
    Clause headings are for ease of reference only.

2.  EFFECTIVE DATE

2.1 Effective Date
    This Agreement (other than this Clause 2 (Effective Date), Clause 6 (Fees
    Costs and Expenses) and Clause 7 (Miscellaneous)) shall become effective on
    the Effective Date.  Clause 2 (Effective Date), Clause 6 (Fees, Costs and
    Expenses) and Clause 7 (Miscellaneous) are effective as at the date hereof.
    In the event that either:

    (i)  the Effective Date has not occurred by the date falling thirty days
         after the date hereof; or

    (ii) the New High Yield Bond has not closed within five Business Days of the
         Effective Date,

    this Agreement shall terminate and the provisions of the Credit Agreement
    and the Participation Agreement shall continue in full force and effect.

2.2 Notification
    The Facility Agent shall promptly notify the Participants of the occurrence
    of the Effective Date and any termination of this Agreement pursuant to
    Clause 2.1.

3.  REPRESENTATIONS

3.1 Repeated Representations
    The Original Borrowers and the Original Guarantors on the date hereof and on
    the Effective Date shall be deemed to make the representations set out in
    Clauses 20.1 (Status) to 20.4 (Execution of the Finance Documents) and
    Clause 20.8 (Validity and Admissibility in Evidence) of the Credit Agreement
    as if the same were set out in full herein and as if each reference therein
    to the "Credit Facility Documents" or the "Finance Documents" includes a
    reference to this Agreement  Provided that in respect of the deemed
    repetition
<PAGE>

    of such representations on the Effective Date, any misrepresentation that
    occurs solely because of the issue of the New High Yield Bond shall be
    waived.

3.2 New Representation
    Each Obligor on the date hereof and on the Effective Date represents and
    warrants to the Participants that there have been no changes to the
    constitutional documents delivered by such Obligor pursuant to the Credit
    Agreement and the Supplemental Deed other than any changes notified and
    evidenced to and acceptable to the Facility Agent on or prior to the
    Effective Date.

4.  AMENDMENTS TO THE CREDIT AGREEMENT AND THE PARTICIPATION AGREEMENT

4.1 The Credit Agreement
    On the Effective Date, the relevant provisions of the Credit Agreement shall
    be amended, read and construed so as to give effect to the provisions set
    out in sub-clauses 4.1.1 to 4.1.10 below:

    4.1.1  The Parent shall procure (and each Borrower which has drawn an
           Advance shall repay its share of the Loan and accrued interest in
           order to ensure) that the Loan and all amounts of accrued interest
           are repaid in full on the Effective Date. No amount payable pursuant
           to this sub-clause 4.1.1 or in respect of an amount payable pursuant
           to this sub-clause 4.1.1 shall constitute an Overdue Amount for the
           purposes of the Participation Agreement.

    4.1.2  Each of the parties hereto agrees that the Facilities will not be
           available for drawing and no Notice of Default may be given by the
           Participating Lender to the EIF during the period beginning on the
           Effective Date and ending on the earlier of:

           (i)    the date falling six months after the Effective Date or, if
                  before the end of such six month period the Parent has served
                  a notice on the Facility Agent requesting an extension of
                  three months, the date falling nine months after the Effective
                  Date;

           (ii)   the date upon which the Facilities are cancelled in full
                  pursuant to the provisions of Clause 13 (Cancellation and
                  Prepayment) of the Credit Agreement; and

           (iii)  the date the Facilities are restructured to reflect the
                  Enlarged Business Plan,

           (the "Restricted Period"). Each of the parties hereto acknowledges
           and confirms that the Banks shall be under no commitment to lend and
           the EIF shall not be obliged to make payments under the Participation
           Agreement during the Restricted Period.

    4.1.3  The Parent and each of the Borrowers, jointly and severally, shall
           pay to the Facility Agent for the account of each Bank a commitment
           commission on the amount of such Bank's Tranche A Term Commitment and
           Revolving
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           Commitment less, in the case of the Participating Lender, the Traded
           Proportion (as defined in the Participation Agreement) of the
           commitment commission calculated at the same rate and payable on the
           same days as it is calculated and payable under Clause 26.1
           (Commitment Commission on the Tranche A Term Facility) and Clause
           26.2 (Commitment Commission on the Revolving Facility) of the Credit
           Agreement.

    4.1.4  The Parent and each of the Borrowers, jointly and severally, shall
           pay to the Facility Agent for the account of the EIF the Traded
           Proportion of the commitment commission referred to in sub-clause
           4.1.3 on the Participated Portion of the Participating Lender's
           Commitment calculated at the same rate and payable on the same days
           as it is calculated and payable under Clause 26.5 of the Credit
           Agreement.

    4.1.5  Each of the Participants agrees, subject to receipt by it of all
           amounts owed to it under sub-clause 4.1.1, to:

           (i)    waive the occurrence of any Event of Default subsisting on the
                  Effective Date;

           (ii)   disapply the provisions of Clause 22 (Financial Condition),
                  Clause 23 (Covenants) and Clause 24 (Events of Default) of the
                  Credit Agreement; and

           (iii)  disapply the provisions of any undertakings or covenants in
                  any of the Security Documents and the provisions of Clauses
                  11.2, 24.2 and 24.3 of the Intercreditor Agreement,

           during the Restricted Period Provided that if this Agreement is
           terminated pursuant to the provisions of Clause 2.1 hereof or
           following the Restricted Period, the Finance Parties shall be
           entitled to exercise any rights they may have under any of the
           Finance Documents as if such waivers and disapplication of provisions
           of the Finance Documents under this sub-clause 4.1.5 had never
           occurred.

    4.1.6  Each of the parties hereto agrees that none of the Obligors will be
           obliged to deliver any statements, reports or information required by
           the terms of Clause 21 (Financial Condition) of the Credit Agreement
           or any other statements, reports or information required by the terms
           of any of the other Finance Documents during the Restricted Period
           save that during the Restricted Period the Parent shall:

           (i)    continue to be obliged to deliver all financial and other
                  information required by the terms of Clause 21.1 (Annual
                  Statements) of the Credit Agreement; and

           (ii)   deliver to the Facility Agent in sufficient copies for the
                  Participants, as soon as the same become available, copies of
                  the Form 10-Q submitted to the Securities and Exchange
                  Commission at the end of each quarter of its financial years.
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    4.1.7  The Parent shall as soon as the same become available deliver to the
           Facility Agent in sufficient copies for the Participants the offering
           memoranda in respect of the New High Yield Bond and the IPO.

    4.1.8  The Parent undertakes to finalise the Enlarged Business Plan and to
           forward it to the Lead Arrangers as soon as reasonably practicable
           and in any event at least 60 days prior to the end of the Restricted
           Period. The Lead Arrangers will forward the Enlarged Business Plan
           and proposals for restructuring the Facilities to the Facility Agent
           as soon as reasonably practicable thereafter and the Facility Agent
           will deliver copies to the Participants promptly on receipt of this
           information. The Lead Arrangers and the Parent will agree a timetable
           for obtaining the views of the Participants and documenting the
           restructuring of the Facilities and, after being informed of the
           same, all the Participants shall use reasonable endeavours to work
           towards this timetable.

    4.1.9  Each of the Participants may determine, in its complete discretion,
           whether it wishes to commit to lend or, in the case of the EIF, to
           risk participate under the Participation Agreement under
           documentation restructuring the Facilities once the Enlarged Business
           Plan and restructuring proposal have been delivered to it. In the
           event a Bank decides not to enter into this restructuring
           documentation at the end of the Restricted Period the Commitment of
           such Bank shall be reduced to zero. In the event the EIF decides to
           terminate the Participation Agreement at the end of the Restricted
           Period the Commitment of the Participating Lender shall be reduced by
           the Participated Portion.

    4.1.10 If the Enlarged Business Plan and/or the restructuring proposal is
           not presented and agreed by the end of the Restricted Period, the
           Facilities shall be cancelled, the Commitment of each Bank shall be
           reduced to zero, the Participation Agreement shall be terminated and
           all the security constituted under the Security Documents shall be
           released in accordance with its terms.

4.2 The Participation Agreement
    Notwithstanding the provisions of Clause 2.3 of the Participation Agreement,
    the Participation Agreement shall remain effective during the Restricted
    Period provided that no Notice of Default may be given by the Participating
    Lender to the EIF during the Restricted Period.  At the end of the
    Restricted Period the EIF shall determine, in its complete discretion, if it
    wishes to terminate the Participation Agreement and shall notify the
    Participating Lender and the Facility Agent accordingly.

4.3 This Agreement
    In the event of any inconsistency between the terms of the Credit Agreement
    and this Agreement or, as the case may be, the terms of the Participation
    Agreement and this Agreement, the terms of this Agreement shall prevail.
    For the avoidance of doubt, the Facility Agent and the Obligors' Agent
    hereby agree this document is designated a Finance Document.
<PAGE>

5.  CONTINUITY AND FURTHER ASSURANCE

5.1 Continuing Obligations
    Each of the parties hereto expressly acknowledges that the provisions of the
    Credit Agreement, the Participation Agreement and the other Finance
    Documents shall, save as amended and modified hereby, continue in full force
    and effect.  All parties hereto acknowledge that the "Effective Date" as
    defined in the Supplemental Deed occurred on 30 March 2000.

5.2 Further Assurance
    Each of the Original Borrowers and the Original Guarantors and the Banks
    shall, at the request of the Facility Agent and at its own expense, do all
    such acts and things necessary or desirable to give effect to the amendments
    and modifications effected or to be effected pursuant to this Agreement.

6.  FEES, COSTS AND EXPENSES

6.1 Transaction Expenses
    The Parent shall within ten days of a written demand, reimburse each of the
    Agents and each of the Lead Arrangers for all reasonable costs and expenses
    (including legal fees) notified to it together with any VAT thereon incurred
    by it in connection with (i) the negotiation, preparation and execution of
    this Agreement and the completion of the transactions herein contemplated
    and (ii) the negotiation, preparation and execution of the Finance Documents
    and the completion of the transactions therein contemplated.

6.2 Preservation and Enforcement of Rights
    The Original Borrowers shall, from time to time on demand of the Facility
    Agent, reimburse the Finance Parties and the EIF for all costs and expenses
    (including legal fees) on a full indemnity basis together with any VAT
    thereon incurred in or in connection with the preservation and/or
    enforcement of any of the rights of the Finance Parties and/or the EIF, as
    the case may be, under this Agreement and any other document referred to in
    this Agreement.

6.3 Stamp Taxes
    The Original Borrowers shall pay all stamp, registration and other taxes to
    which this Agreement, any other document referred to in this Agreement or
    any judgment given in connection herewith is or at any time may be subject
    (other than those imposed by reason of assignment or novation) and shall,
    from time to time on demand of the Facility Agent, indemnify the Finance
    Parties and the EIF against any liabilities, costs, claims and out of pocket
    expenses resulting from any failure to pay or any delay in paying any such
    tax.

7.  MISCELLANEOUS

7.1 Incorporation of Terms
    The provisions of Clause 35.1 (Binding Agreement), Clause 39 (Remedies and
    Waiver, Partial Invalidity), Clause 43 (Governing Law) and Clause 44
    (Jurisdiction) of the Credit Agreement shall be incorporated into this
    Agreement as if set out in full herein and as if
<PAGE>

    references therein to this Agreement or the Finance Documents are references
    to this Agreement.

7.2 Counterparts
    This Agreement may be executed in any number of counterparts, with different
    parties executing different counterparts all of which taken together shall
    constitute one and the same instrument.

AS WITNESS the hands of duly authorised representatives of the parties hereto
the day and year first before written.
<PAGE>

                                  SIGNATURES

The Parent
COMPLETEL EUROPE N.V.

By:             /s/ ANNA LASCAR

Address:        Kruisweg 609
                2132 NA Hoofddorp
                The Netherlands

Fax:            00 31 20 666 1666


The Obligors' Agent
COMPLETEL S.A.S.

By:             /s/ ANNA LASCAR

Address:        Tour Egee
                9-11, allee de l'Arche
                92671 Courbevoie Cedex
                France

Fax:            00 331 729 22614


The Original Borrowers
COMPLETEL ECC B.V.

By:             /s/ ANNA LASCAR

Address:        Kruisweg 609
                2132 NA Hoofddorp
                The Netherlands

Fax:            00 31 20 666 1666


COMPLETEL GmbH

By:             /s/ ANNA LASCAR

Address:        Hans-Stiessberger - Strasse 2B
                85540 Harr bei Munchen
                Germany

Fax:            00 49 89 95 465 199
<PAGE>

COMPLETEL SERVICES S.A.S.

By:             /s/ ANNA LASCAR

Address:        Tour Egee
                9-11, allee de l'Arche
                92671 Courbevoie Cedex
                France

Fax:            00 33 1 7292 2614


COMPLETEL S.A.S.

By:             /s/ ANNA LASCAR

Address:        Tour Egee
                9-11, allee de l'Arche
                92671 Courbevoie Cedex
                France

Fax:            00 33 1 7292 2614


The Original Guarantors
COMPLETEL EUROPE N.V.

By:             /s/ ANNA LASCAR

Address:        Kruisweg 609
                2132 NA Hoofddorp
                The Netherlands

Fax:            00 31 20 666 1666


COMPLETEL ECC B.V.

By:             /s/ ANNA LASCAR

Address:        Kruisweg 609
                2132 NA Hoofddorp
                The Netherlands

Fax:            00 31 20 666 1666
<PAGE>

COMPLETEL HOLDING I B.V.

By:             /s/ ANNA LASCAR

Address:        Kruisweg 609
                2132 NA Hoofddorp
                The Netherlands

Fax:            00 31 20 666 1666


COMPLETEL HOLDING II B.V.

By:             /s/ ANNA LASCAR

Address:        Kruisweg 609
                2132 NA Hoofddorp
                The Netherlands

Fax:            00 31 20 666 1666


COMPLETEL GmbH

By:             /s/ ANNA LASCAR

Address:        Hans-Stiessberger - Strasse 2B
                85540 Harr bei Munchen
                Germany

Fax:            00 49 89 95 465 199


COMPLETEL SERVICES S.A.S.

By:             /s/ ANNA LASCAR

Address:        Tour Egee
                9-11, allee de l'Arche
                92671 Courbevoie Cedex
                France

Fax:            00 33 1 7292 2614


COMPLETEL S.A.S.

By:             /s/ ANNA LASCAR

Address:        Tour Egee
                9-11, allee de l'Arche
                92671 Courbevoie Cedex
                France

Fax:            00 33 1 7292 2614
<PAGE>

ACCES ET SOLUTIONS INTERNET S.A.R.L.

By:             /s/ ANNA LASCAR

Address:        Double Mixte
                43 Boulevard du 11 Novembre 1918
                69625 Villeurbanne Cedex
                France

Fax:            00 33 4 78 93 00 99


COMPLETEL UK LIMITED

By:             /s/ ANNA LASCAR

Address:        c/o Holme Roberts & Owen
                Heathcoat House
                20 Savile Row
                London W1X 1AE

Fax:            +44 (0)207 287 9344


iPCENTA LIMITED

By:             /s/ ANNA LASCAR

Address:        Vaughan Chambers
                Vaughan Road
                Harpenden
                Hertfordshire
                AL5 4EE

Fax:            +44 (0)208 960 0820


COMPLETEL SPC

By:             /s/ ANNA LASCAR

Address:        c/o Holme Roberts & Owen
                Heathcoat House
                20 Savile Row
                London W1X 1AE

Fax:            +44(0) 207 287 9344
<PAGE>

COMPLETEL SPC II

By:             /s/ ANNA LASCAR

Address:        c/o Holme Roberts & Owen
                Heathcoat House
                20 Savile Row
                London W1X 1AE

Fax:            +44(0) 207 287 9344


The Lead Arrangers

GOLDMAN SACHS INTERNATIONAL

By:             /s/ DAVID COTTAM

Address:        Peterborough Court
                133 Fleet Street
                London EC4A 2BB

Fax:            +44 171 774 1313


PARIBAS

By:             /s/ BENOIT TANGUY

Address:        37 Place du Marche Saint Honore
                75031 Paris Cedex 01

Fax:            + 33 1 42 98 0979


The Facility Agent

PARIBAS

By:             /s/ GABRIEL LEFEBVRE


The Security Agent

PARIBAS

By:             /s/ GABRIEL LEFEBVRE
<PAGE>

The Banks

GOLDMAN SACHS INTERNATIONAL

By:             /s/ DAVID COTTAM


PARIBAS

By:             /s/ BENOIT TANGUY


BARCLAYS BANK PLC

By:             /s/ ANDREW VINE


CITIBANK INTERNATIONAL PLC

By:             /s/ PAREEJAT SINGHAL


COMPTOIR DES ENTREPRENEURS

By:             /s/ EMMANUEL GILLET-LAGARDE


CREDIT LYONNAIS

By:             /s/ JEAN-LOUIS DE BERGH


MERRILL LYNCH CAPITAL MARKETS BANK LIMITED

By:             /s/ BERNARD HOEY              /s/ SHANE O'NEILL


SCOTIABANK EUROPE PLC

By:             /s/ P. SHANLEY


AUSTRALIA AND NEW ZEALAND BANKING GROUP LIMITED
ACTING THROUGH ITS PARIS BRANCH

By:             /s/ PHILIPPE CASSIERS
<PAGE>

BANCA NAZIONALE DEL LAVORO S.p.A. - Paris Branch

By:             /s/ SERGE BUZIN               /s/ GIULIANO VIOLETTA


CREDIT AGRICOLE INDOSUEZ

By:             /s/ ALEXANDRA BOLESLAWSKI     /s/ YANNICK RATTE


IBM FRANCE FINANCEMENT S.A.

By:             /s/ LAURENT DU FAYET


The Risk Participant

EUROPEAN INVESTMENT FUND

By:             /s/ GERBRAND G. HOP