<PAGE>

                                                                     Exhibit 4.8

                       AMENDMENT NO. 3, WAIVER AND CONSENT

            Amendment No. 3, Waiver and Consent, dated as of March _, 2006 (this
"Amendment No. 3"), relating to the Investment and Note Purchase Agreement (the
"Existing Agreement"), dated as of June 23, 2005, by and among Viatel Holding
(Bermuda) Limited (the "Company") and the purchasers named therein and the
Company's Senior Secured Increasing Rate Notes Due 2007 (the "New Notes").
Capitalized terms used in this Amendment No. 3 and not defined shall have the
meanings assigned to them in the Existing Agreement.

            WHEREAS, the parties hereto have agreed that the parties set forth
on Schedule I attached hereto ("New Purchasers") will purchase additional New
Notes in an aggregate principal amount equal to $8,802,600 ("2006 Notes");

            WHEREAS, the parties have agreed, subject to and upon the terms and
conditions set forth herein, to amend the Existing Agreement as set forth herein
in order to provide for the 2006 Notes;

            WHEREAS, the Board of Directors of the Company has determined that
entering into this Amendment No. 3 and related documentation is in the best
interests of the Company and have approved and authorized the execution of the
documents necessary to give effect to this Amendment No. 3 and related
documentation; and

            WHEREAS, each of the holders of the New Notes (the "New Holders")
has determined that this Amendment No. 3 is in its best interests and has
approved this Amendment No. 3;

            NOW, THEREFORE, the parties hereto, intending to be legally bound,
hereby agree as follows.

      1. Consent to Special Share Holder Action. Each New Holder hereby consents
to the holder of the Special Share entering into a consent pursuant to Section
76A of the Company's bye-laws that will allow the Company to issue the 2006
Notes pursuant to this Amendment No. 3 and to execute any other documents or
transactions related thereto.

      2. Amendment to Existing Agreement. Each of the Company and each New
Holder hereby agrees that the Existing Agreement is hereby amended by:

            (i) Replacing the second paragraph of the recitals with the
following paragraph:

            "WHEREAS, the Company proposes to issue and sell US$16,000,000
aggregate principal amount of its Senior Secured Increasing Rate Notes due 2007
(the "2005 Notes") and US$8,802,600 aggregate principal amount of its Tranche A
Senior Secured Increasing Rate Notes due 2007 (the "2006 Notes") to the several
Purchasers;"

            (ii) Inserting the following new definition in alphabetical order in
Section 1.01 of the Existing Agreement:

            "2005 Notes" has the meaning set forth in the recitals.

<PAGE>

            "2006 Notes" has the meaning set forth in the recitals."

            (iii) Replacing the definition of Notes in Section 1.01 with the
following definition:

            "Notes" means the 2005 Notes and the 2006 Notes."

            (ii) Replacing the existing Schedule I with the Schedule I attached
hereto.

      3. Delivery of and Payment for the Notes.

            (i) Subject to the terms and conditions set forth herein and in the
Existing Agreement, delivery of and payment for the 2006 Notes shall be made at
the offices of Wachtell, Lipton, Rosen & Katz, or at such other place as shall
be agreed upon by the New Purchasers and the Company, at 10:00 am (New York
time) on the first Business Day following the satisfaction or waiver of all of
the conditions set forth in paragraph 6 hereof (other than those conditions that
by their nature are to be satisfied or waived on the Amendment No. 3 Closing
Date, but subject to the satisfaction or waiver of those conditions), or at such
other time and date as shall be agreed upon by the New Purchasers and the
Company (such date and time of payment and delivery being referred to herein as
the "Amendment No. 3 Closing Date").

            (ii) On the Amendment No. 3 Closing Date, payment of the purchase
price for the 2006 Notes shall be made to the Company by wire or book-entry
transfer in immediately available funds to such account or accounts as the
Company shall specify prior to the Amendment No. 3 Closing Date or by such other
means as the parties hereto shall agree prior to the Amendment No. 3 Closing
Date against delivery to the New Purchasers of the certificates evidencing the
2006 Notes. Time shall be of the essence, and delivery at the time and place
specified pursuant to this Amendment No. 3 is a further condition of the
obligations of the New Purchasers hereunder. Upon delivery, the 2006 Notes shall
be in definitive certificated form, registered in such names and in such
denominations as the New Purchasers shall have requested in writing prior to the
Amendment No. 3 Closing Date.

            (iii) When delivered by the Company on the Amendment No. 3 Closing
Date, the 2006 Notes shall be fully authorized, duly and validly issued, and
free and clear of Liens (other than Liens specifically contemplated by the
Transaction Documents).

      4. Further Assurances. In consideration for the purchase of the 2006 Notes
and other consideration provided for in this Amendment No. 3, as security for
the due and punctual payment of the 2006 Notes, the Company agrees that at any
time and from time to time, at the Company's expense, the Company will promptly
execute and deliver all further instruments and documents, and take all further
action that the Lenders may reasonably request, in order to perfect and protect
the Security Interest (as defined in the New Notes) granted in respect of the
New Notes or to enable the New Holders to exercise or enforce their rights,
powers and remedies with respect to the Security Interest and any other
collateral that may secure the New Notes in the future.

      5. Representations and Warranties.

<PAGE>

            (i) The Company represents and warrants to, and agrees with, the New
Holders that:

                  (a) The Company has the corporate power and authority to
execute, deliver and perform, as applicable, its obligations under this
Amendment No. 3 and any other documents contemplated hereby to which it is or
will be a party;

                  (b) The execution, delivery and performance of this Amendment
No. 3 (a) have been duly authorized by all necessary corporate action on the
part of the Company, (b) will not constitute a violation of any provision of any
Applicable Law or any order of any Governmental Authority applicable to the
Company or any of its properties or assets, (c) will not violate any provision
of the charter, bye-laws, or any other organizational document of, or other
similar instrument to which the Company is a party or by which the Company or
any of its properties or assets are bound or to which the Company is subject,
(d) will not be in conflict with, result in a breach of, or constitute (with due
notice or lapse of time or both) a default under, or create any right to
terminate, any indenture, agreement, bond, note, mortgage, deed of trust, or
other instrument to which the Company is a party or by which the Company or any
of its properties or assets are bound or to which the Company is subject and (e)
will not result in the creation or imposition of (or the obligation to create or
impose) any lien, charge or encumbrance of any nature whatsoever upon any of the
properties or assets of the Company other than pursuant to the Security
Documents or the other Transaction Documents (as amended);

                  (c) Upon its execution and delivery by the Company, this
Amendment No. 3 and each Transaction Document amended pursuant hereto shall
constitute or continue to constitute the legal, valid and binding obligation of
the Company, enforceable against the Company in accordance with its terms,
except as such enforceability may be limited by applicable bankruptcy,
insolvency and similar laws affecting creditors' rights generally and to general
principles of equity, irrespective of whether such enforceability is considered
in a proceeding at law or equity;

                  (d) The Company is not in violation of any Applicable Law or
any restrictions of record or agreements affecting the Security Interest, except
for violations which in the aggregate could not reasonably be expected to have a
Material Adverse Effect;

                  (e) As of the Amendment No. 3 Closing Date, there are no
outstanding Defaults or Events of Default (as defined in the New Notes) under
the existing New Notes;

                  (f) The 2006 Notes constitute Notes under the Existing
Agreement and the other Transaction Documents, including, without limitation,
the Security Documents; and

                  (g) All representations and warranties set forth in the
Existing Agreement and the other Transaction Documents are true and correct in
all material respects on and as of the Amendment No. 3 Closing Date with the
same effect as if made on and as of such date, except to the extent such
representations and warranties expressly relate to an earlier date or to the
extent qualified by the disclosure schedules hereto.

<PAGE>

            (ii) Each Purchaser severally as to itself, and not jointly, hereby
represents and warrants to the Company on the date hereof that all
representations and warranties set forth in Section 4.02 of the Existing
Agreement are true and correct in all material respects on and as of the date of
the Amendment No. 3 Closing Date with the same effect as if made on and as of
such date.

      6. Conditions to Effectiveness. This Amendment No. 3 shall become
effective on the date upon which the New Holders notify the Company that they
are satisfied that each of the following conditions have been met:

            (i) The New Holders shall have received an executed counterpart of
this Amendment No. 3 bearing the signature of the Company;

            (ii) The Company shall have delivered to the New Holders such other
documents, agreements, instruments and information as the New Holders may
reasonably request;

            (iii) The Company shall have included, in the principal amount of
the 2006 Notes, an amendment fee equal to 2% of the original principal amount of
the 2006 Notes, set forth as the "Funded Amount of 2006 Notes" in Schedule I
attached hereto.

            (iii) The New Holders shall have received reimbursement or other
payment of all reasonable costs, fees and expenses of the Lenders (including,
without limitation, the fees and disbursements of Wachtell, Lipton, Rosen &
Katz), incurred in connection with the restructuring of the Company, including
without limitation, this Amendment No. 3, and all other documents to be
delivered in connection herewith;

            (iv) The representations and warranties set forth herein and in
Article III of the Existing Agreement and in any other Transaction Documents
then in existence shall be true and correct in all material respects, and no
Default or Event of Default under the existing New Notes shall have occurred and
be continuing; and

            (v) The Company, the Law Debenture Trust Corporation P.L.C. and the
holders of the Existing Notes shall have executed and delivered to the New
Holders an executed counterpart of a subordination agreement, which
subordination agreement shall be in form and substance satisfactory to the New
Holders.

      7. Governing Law; Jurisdiction; Waiver of Trial by Jury. This Amendment
No. 3 shall be construed in accordance with the internal laws of the State of
New York without regard to the conflicts of laws provisions thereof. Each party
hereto hereby irrevocably submits to the jurisdiction of any court of the State
of New York located in the County of New York or the United States District
Court for the Southern District of the State of New York, any appellate courts
from any thereof (any such court, a "New York Court") or any court of the United
Kingdom located in London, or any appellate courts from any thereof (any such
court, a "U.K. Court"), for the purpose of any suit, action or other proceeding
arising out of or relating to this Amendment No. 3 or under any applicable
securities laws and arising out of the foregoing, which is brought by or against
such party, and each such party hereby irrevocably agrees that all claims in
respect of any such suit, action or proceeding will be heard and determined in
any New York Court or U.K. Court. Each such party hereby agrees not to commence
any action, suit or

<PAGE>

proceeding relating to this Amendment No. 3 other than in a New York Court
except to the extent mandated by applicable law. Each such party hereby waives
any objection that it may now or hereafter have to the venue of any such suit,
action or proceeding in any such court or that such suit, action or proceeding
was brought in an inconvenient court and agree not to plead or claim the same.
EACH PARTY TO THIS AMENDMENT NO. 3 HEREBY EXPRESSLY WAIVES ANY RIGHT TO TRIAL BY
JURY OF ANY CLAIM, DEMAND, ACTION OR CAUSE OF ACTION ARISING UNDER THIS
AMENDMENT NO. 3 OR IN ANY WAY CONNECTED WITH OR RELATED OR INCIDENTAL TO THE
DEALINGS OF THE PARTIES HERETO OR ANY OF THEM WITH RESPECT THIS AMENDMENT NO. 3,
OR THE TRANSACTIONS RELATED HERETO, IN EACH CASE WHETHER NOW EXISTING OR
HEREAFTER ARISING, AND WHETHER FOUNDED IN CONTRACT OR TORT OR OTHERWISE; AND
EACH PARTY HEREBY AGREES AND CONSENTS THAT ANY SUCH CLAIM, DEMAND, ACTION OR
CAUSE OF ACTION SHALL BE DECIDED BY COURT TRIAL WITHOUT A JURY, AND THAT ANY
PARTY TO THIS WAIVER AND CONSENT MAY FILE AN ORIGINAL COUNTERPART OR A COPY OF
THIS SECTION WITH ANY COURT AS WRITTEN EVIDENCE OF THE CONSENT OF THE
SIGNATORIES HERETO TO THE WAIVER OF THEIR RIGHT TO TRIAL BY JURY.

      8. Separability. If any one or more of the provisions contained in this
Amendment No. 3 shall, for any reason, be held to be invalid, illegal or
unenforceable in any respect, such invalidity, illegality or unenforceability
shall not affect any other provisions of this Amendment No. 3 and such provision
shall be interpreted to the fullest extent permitted by the law; provided that
the Company and each New Holder shall use their reasonable best efforts to find
and employ an alternative means to achieve the same or substantially the same
result as that contemplated by such provision.

      9. Successors and Assigns. All agreements of the Company and the New
Holders hereunder shall bind their respective successors and assigns.

<PAGE>

IN WITNESS HEREOF, THE PARTIES HERETO HAVE CAUSED THIS Amendment No. 3 TO BE
DULY EXECUTED AS OF THE DATE FIRST WRITTEN ABOVE:

VIATEL HOLDING (BERMUDA) LIMITED

By: /s/___________________________
    Name: Lucy Woods
    Title: Chief Executive Officer

<PAGE>

      AGREED AND ACCEPTED AS OF THE DATE FIRST WRITTEN ABOVE:

MORGAN STANLEY & CO. INCORPORATED           VARDE PARTNERS, INC.

By: /s/_______________________              By: /s/____________________
    Name: Thomas E. Doster, IV                  Name: George Hicks
    Title: Managing Director                    Title: Managing Partner

STONEHILL INSTITUTIONAL PARTNERS, L.P.

By: _________________, its ________

By: /s/________________________
       Name: Christopher Wilson
       Title: General Partner

<PAGE>

                                                         SCHEDULE 1 - PURCHASERS

2005 NOTES

<TABLE>
<CAPTION>
                                                                                       Principal Amount
            Purchasers                                Address                            of 2005 Notes
---------------------------------     --------------------------------------    ---------------------------
<S>                                   <C>                                       <C>
Morgan Stanley & Co.                  Morgan Stanley & Co. Incorporated                 $    12,631,579
Incorporated                          1585 Broadway
                                      New York, NY 10036
                                      Attn: Thomas E. Doster
                                      Tel: (212) 761-0841
                                      Fax: (212) 507-4756

Varde Partners, Inc.                  Varde Partners, Inc.                              $     3,062,201
                                      8500 Normandale Lake Boulevard
                                      Suite 1570
                                      Minneapolis, MN 55437-3813
                                      Attn: George G. Hicks
                                      Tel: (952) 893-1554
                                      Fax: (952)893-9613

Stonehill Institutional Partners,     Stonehill Institutional Partners, L.P.            $       306,220
L.P.                                  885 Third Avenue, 30th Floor
                                      New York, NY 10022
                                      Tel: (212) 739-7474
                                      Attn: Chris Wilson
                                            Anne Mauro
                                            Steve Nelson

         Total                                                                          $ 16,000,000.00
</TABLE>

2006 NOTES

<TABLE>
<CAPTION>
                                                                         Principal Amount      Funded Amount
       Purchasers                             Address                      of 2006 Notes       of 2006 Notes
-----------------------       --------------------------------------     ----------------      -------------
<S>                           <C>                                        <C>                   <C>
Morgan Stanley & Co.          Morgan Stanley & Co. Incorporated          $    6,949,421        $   6,813,158
Incorporated                  1585 Broadway
                              New York, NY 10036
                              Attn: Thomas E. Doster
                              Tel: (212) 761-0841
                              Fax: (212) 507-4756

Varde Partners, Inc.          Varde Partners, Inc.                       $    1,684,708        $   1,651,675
                              8500 Normandale Lake Boulevard
</TABLE>

<PAGE>

<TABLE>
<S>                           <C>                                        <C>                   <C>
                              Suite 1570
                              Minneapolis, MN  55437-3813
                              Attn:  George G. Hicks
                              Tel: (952) 893-1554
                              Fax: (952)893-9613

Stonehill Institutional       Stonehill Institutional Partners, L.P.     $      168,471        $     165,167
Partners, L.P.                885 Third Avenue, 30th Floor
                              New York, NY 10022
                              Tel: (212) 739-7474
                              Attn: Chris Wilson
                                    Anne Mauro
                                    Steve Nelson

         Total                                                           $ 8,802,600.00        $8,630,000.00
</TABLE>