Exhibit 10.21  TRANSITION
SERVICES AGREEMENT  This
TRANSITION SERVICES AGREEMENT (this Agreement), dated as of April 1,
2004, is entered into by and among ICG Telecom Group, Inc., a Colorado
corporation (ICG) and Level 3 Communications, LLC,a Delaware limited liability
company (Level 3).  WHEREAS, ICG (and its parent company) and
Level 3 have entered into an Asset Purchase Agreement, dated as of April 1,
2004 (the Purchase Agreement), relating to the purchase and sale of
the certain assets and the assumption of certain liabilities relating to the
Business;  WHEREAS, pursuant to the Purchase
Agreement certain Numbers used in the Business will not be transferred or
assigned to Level 3 until after Closing;  WHEREAS, after the Closing and in order to
provide service under the Customer Contracts which have been conveyed and
assigned to Level 3, Level 3 will require for a limited period of time the use
of services to be delivered by ICG to Level 3 using certain Numbers that have
not yet been transferred or assigned to Level 3;  NOW,
THEREFORE,
in consideration of the mutual covenants and agreements contained herein and
for other good and valuable consideration, the receipt and sufficiency of which
are hereby acknowledged, the parties hereto agree as follows:  ARTICLE I.  DEFINITIONS  Capitalized
terms used but not otherwise defined herein shall have the meanings specified
in the Purchase Agreement.  In addition,
the following capitalized terms shall have the meanings set forth below:  A Numbers
shall mean those Numbers delineated as such on tabs 5, 6 and 7 of the
spreadsheet attached as Exhibit B.  B Numbers
shall mean those Numbers delineated on tabs 5, 6, and 7 of the spreadsheet
attached as Exhibit B.  ICG Underlying Service Contracts are
those agreements, understandings or contracts necessary to provide the ICG
Transition Services, including, without limitation, those agreements delineated
on Exhibit A hereto.  Number
Termination Notice shall mean a notice delivered by Level 3 to ICG,
whereby Level 3 notifies ICG that Level 3 no longer needs ICG Transition
Services with respect to those Numbers delineated in such notice.  1 
   POP
is a point of presence used by ICG in the operation of the Business, as
delineated on tabs 2 and 3 of the spreadsheet attached as Exhibit B.  Retained Numbers shall mean those
Numbers, the use of which, as of the Closing, has not yet been transferred or
assigned to Level 3, and which are temporarily retained by ICG pursuant to the
terms of the Purchase Agreement and this Agreement.  Retained
POP shall mean a POP, the use of which has not yet been terminated
pursuant to Section2.1 hereof.  Retained
Uncovered LATA shall mean an Uncovered LATA, the services within which
have not yet been terminated pursuant to Section 2.1 hereof.  Services
shall mean, collectively, ICG Transition Services and Migration Services, as
hereinafter defined.  Uncovered
LATA is an uncovered Local Access and Transport Area in which ICG operates
the Business, as delineated on tab 4 of the spreadsheet attached as Exhibit_B.  ARTICLE II.  PROVISION OF
SERVICES BY ICG  Section
2.1.ICG Transition Services.  ICG shall provide to Level 3, with respect to any Assumed Customer
Contract, access to and use of the Retained Numbers and any goods and services
provided to ICG related thereto (or which ICG has the right to obtain under the
terms of its existing contractual arrangements) in connection with the
Business, including, without limitation, those services described on Exhibit
C (collectively, the ICG Transition Services) as of the date of the Purchase
Agreement during the period (the ICG Service Period) from the Closing
Date until, with respect to each Retained Number, each Retained POP, and each
Retained Uncovered LATA, the first to occur of the following (each an Effective
Date):  (a)           with respect to
a Retained Number, 15 days after delivery of a Number Termination Notice
delineating such Retained Number; provided, however, the ICG Service Period for
any Retained Number used by ICG in providing services to a customer under an
Excluded Customer Contract shall be deemed to end (and the Effective Date shall
be deemed to have occurred) as of the Closing Date, without further notice from
Level 3; and  (b)           with respect to
a POP, 30 days after the delivery of a Number Termination Notice for the last
Retained Number corresponding to such POP; provided, however, that the ICG
Service Period for any POP used by ICG solely in providing services to any customer(s)
under any Excluded Customer Contract(s) shall be deemed to end (and the
Effective Date shall be deemed to have occurred) as of the Closing Date,
without further notice from Level 3.  2 
   (c)           with respect to
an Uncovered LATA, 30 days after the delivery of a Number Termination Notice
for the last Retained Number corresponding to such Uncovered LATA; provided,
however, that the ICG Service Period for any Uncovered LATA used by ICG solely
in providing services to any customer(s) under any Excluded Customer
Contract(s) shall be deemed to end (and the Effective Date shall be deemed to
have occurred) as of the Closing Date, without further notice from Level 3.  (d)           the effective
date of termination of the ICG Service Period, as set forth in written notice
from Level 3 to ICG.  Each of Level 3 and ICG acknowledge and agree
that upon receipt by ICG of any Number Termination Notice, ICG will have the
right to terminate (subject to the terms of this Section 2.1 and Exhibit D
hereto) the Services with respect to the applicable Number (as set forth in
such Number Termination Notice), POP (if such Number Termination Notice
requests termination of the last Retained Number corresponding to such POP), or
Uncovered LATA (if such Number Termination Notice requests termination of the
last Retained Number corresponding to such Uncovered LATA).  Section 2.2.           Pass Through Rights.  The ICG Transition Services shall be
provided by ICG to Level 3 in substantially the same manner and on
substantially the same basis (including as to policies, procedures, practices
and timeliness) as the goods and services provided to ICG under existing
contractual arrangements relating to the Business.  Without limiting the generality of the foregoing, ICG agrees to
perform the ICG Services to the standards and service levels set forth in the
respective Assumed Customer Contracts (SLA Standards).  If and to the extent that ICG is or becomes
entitled to exercise any rights or remedies from underlying carriers or
subcontractors used to deliver the ICG Transition Services, and if and to the
extent ICG does not promptly enforce such rights and remedies, ICG hereby
assigns such right and remedies to Level 3 with respect to the ICG Transition
Services.  ICG agrees to enforce and
prosecute such rights and remedies upon consultation with Level 3 with respect
thereto.  Section 2.3.           SLA Remedies.  In the event ICG fails to perform the ICG Transition Services to
the SLA Standards, ICG shall reimburse Level 3 in cash in an amount equal to
any payments made or service credits granted by Level 3 to customers under
Assumed Customer Contracts relating to such failure to perform the ICG Services
to the SLA Standards.  Without limiting
the foregoing remedy, Level 3 may, at its option, perform any ICG Transition
Services which ICG fails to perform and ICG shall cooperate, and shall cause
its employees and agents to cooperate, with Level 3 in such performance of the
ICG Transition Services.  Section 2.4.           Actions with Respect to Certain Agreements.  Except as otherwise consented to in writing
by Level 3, which consent may be withheld or granted in Level 3s sole
discretion, during the ICG Service Period:  (a)           With respect to each ICG Underlying
Service Contract that will or may expire during the ICG Service Period, ICG
shall take such steps as are necessary to continue such ICG Underlying Service
Contract or otherwise replace the services provided thereunder until the
expiration of the ICG Service Period for the respective Number, POP, or
Uncovered LATA, as applicable.  3 
   (b)           ICG shall (i) perform in all material
respects its obligations under each ICG Underlying Service Contract, and (ii)
not settle, release or forgive any claim or litigation or waive any right under
any ICG Underlying Service Contract.  (c)           Upon
reasonable request by Level 3, ICG shall provide Level 3 with additional
information with regard to any of the ICG Underlying Service Contracts.  Section 2.5.           Migration Services.  During the ICG Service Period, ICG will
assist Level 3 in porting, transferring, or assigning the Numbers to Level 3 in
accordance with the terms set forth on Exhibit D (Migration Services),
for no additional charge.  Section 2.6.           SLAs for Migration Services.ICG agrees to perform the Migration Services to
the standards and service levels set forth on Exhibit E (Migration
Services Standards).  Section 2.7.           Migration SLA Remedies.  In the event ICG fails to perform the
Migration Services to the Migration Services Standards (a Migration Failure),
then from and after the date of such breach, and notwithstanding Article III
hereof, Level 3 shall, during the period of Migration Failure or delay
resulting therefrom, have no obligation to pay (a) any Retained POP Charges or
Uncovered LATA Charges with respect to the affected Retained POP or Retained
Uncovered LATA (as the case may be) that are in each case caused by the
Migration Failure or resulting delay; or (b) any Retained Number Charges as set
forth on the applicable tabs of the spreadsheet attached as Exhibit B,
that are in each case caused by the Migration Failure or resulting delay.  Any Migration Failure that continues without
cure, (X) for emergency porting requests, twenty-four (24) hours following
notice from Level 3 to ICG at 303-461-4937 and (Y) in all other instances,
seventy-two (72) hours following notice from Level 3 to ICG at 303-461-4937
shall be deemed a Continued Migration Failure.   Level 3 shall have no obligation to pay any Excess Charges (as
hereinafter defined). For the purposes hereof, the term Excess Charges means
(a) any Retained POP Charges or Uncovered LATA Charges with respect to the
affected Retained POP or Retained Uncovered LATA (as the case may be) or (b) any
Retained Number Charges as set forth on the applicable tabs of the spreadsheet
attached as Exhibit B, that would, in each case, not have been incurred
but for a Continued Migration Failure. 
Without limiting the foregoing remedy, Level 3 may, at its option,
perform any Migration Services which ICG fails to perform and ICG shall
cooperate, and shall cause its employees and agents to cooperate, with Level 3
in such performance of the Migration Services.  Section 2.8.           Consents.  ICG and Level 3 will reasonably cooperate with each other in
seeking to obtain all third party consents, licenses, sublicenses or approvals
to the extent, if any, necessary to permit or facilitate the provision of the
ICG Transition Services and the Migration Services as provided herein.  Section 2.9.           Billing Support.Until
the end of the calendar month immediately following the calendar month in which
the ICG Service Period ends, ICG will provide Level 3 with the billing support
services and deliver to Level 3 the reports described on ExhibitF, for
no additional charge.  4 
   Section 2.10.        Incorrect Data.In
the event that the information provided by ICG to Level 3 in Exhibit A or
Exhibit B to this Agreement is incorrect (Incorrect Data) and such Incorrect
Data results in a delay of the Level 3 migration contemplated by this Agreement
and the Purchase Agreement (including, without limitation, any delay with
regard to an Effective Date of any Retained Number, POP or Uncovered LATA), then
during the period of delay Level 3 shall have no obligation to pay (a) any
Retained POP Charges or Uncovered LATA Charges with respect to any affected
Retained POP or Retained Uncovered LATA (as the case may be); or (b) any
Retained Number Charges as set forth on the applicable tabs of the spreadsheet
attached as Exhibit B, that, in each case, are caused by the Incorrect
Data.  Section 2.11.        Adequate Personnel.ICG
agrees that adequate personnel will be devoted to the provision of the Services
hereunder.  In the event that any of the
individuals (each, aKey Business Employee) identified on the Key
Business Employee List (as hereinafter defined)are reassigned within ICG
such that the Key Business Employee will be tasked with devoting substantially
less time in support of the Business (as compared to immediately prior the
Closing Date), ICG shall provide Level 3 with notice as promptly as practicable
of its intent to reassign such Key Business Employee along with a written plan
accounting for continued provision of the Services prior to such reassignment.
For the purposes hereof, the term Key Business Employee List shall mean a
list composed by Level 3 of no more than twenty (20) Key Business Employees to
be delivered to ICG in writing within a week following the Closing Date.  ARTICLE III.  PRICING AND
PAYMENT  Section
3.1.           Retained Number Charges. 
During the applicable ICG Service Period with respect to each Retained
Number, Level 3 shall pay ICG the amount per Retained Number per day as set
forth on tabs 5, 6 and 7 of the spreadsheet attached as Exhibit B (the Retained
Number Charges).  Section
3.2.           Retained POP Charges. 
During the applicable ICG Service Period with respect to each Retained
POP, Level 3 shall pay ICG the amount per Retained POP per day as set forth on
tabs 2 and 3 of the spreadsheet attached as Exhibit B (the Retained
POP Charges).  Section
3.3.           Uncovered LATA Charges. 
During the applicable ICG Service Period with respect to each Retained
Uncovered LATA, Level 3 shall pay ICG the amount per Retained Uncovered LATA
per day as set forth on tab 4 of the spreadsheet attached as Exhibit B
(the Uncovered LATA Charges).  Section
3.4.           Management Fee. 
During the ICG Service Period, Level 3 shall pay ICG the following
amounts as a management fee (the Management Fee):  5 
   Applicable Period of
  ICG Service Period
  
  Management Fee
  for such PeriodFirst calendar month following Closing
  
  $
  300,000Second calendar month following Closing
  
  $
  200,000Third calendar month following Closing
  
  $
  100,000Fourth calendar month following Closing
  
  $
  100,000Each additional day thereafter
  
  $
  1,500
  per day  Section
3.5.           Payment. 
Subject to Section 2.7 hereof, Level 3 shall pay ICG the Retained Number
Charges, the Retained POP Charges, the Uncovered LATA Charges, and the
Management Fee monthly on or before the 15th day after the end of the calendar
month in which the charges were incurred. 
ICG shall deliver to Level 3 an invoice for such charges no later than
the 1st day after the end of the calendar month in which the charges were
incurred, which invoice shall be substantially in the form as set forth on the
applicable invoice tab of the Spreadsheet attached as Exhibit B.  ARTICLE IV.  CERTAIN COVENANTS  Section
4.1.Indemnification.  The covenants and agreements
contained herein shall be deemed to be covenants contained in the Purchase
Agreement for purposes of the rights to indemnification set forth in Article
VIII thereof.  Section
4.2.           Proprietary Information and
Rights.  Each party acknowledges that the other
possesses, and will continue to possess, information that has been created,
discovered or developed by them and/or in which property rights have been
assigned or otherwise conveyed to them, which information has commercial value
and is not in the public domain. The proprietary information of each party will
be and remain the sole property of such party and its assigns. Each party shall
use the same degree of care that it normally uses to protect its own
proprietary information to prevent the disclosure to third parties of
information that has been identified as proprietary by written notice to such
party from the other party. Neither party shall make any use of the information
of the other that has been identified as proprietary, or would reasonably be
understood to be proprietary, except as contemplated or required by the terms
of this Agreement. Notwithstanding the foregoing, this Section shall not apply
to any information that a party can demonstrate: (a) was, at the time of
disclosure to it, in the public domain through no fault of such party; (b) was
received after disclosure to it from a third party who had a lawful right to
disclose such information to it; or (c) was independently developed by the
receiving party.  Each party
agrees to grant to the other partys personnel, access to locations,  6 
   systems
and information (subject to the provisions contained herein) as necessary for
the other party to perform its obligations hereunder.  ARTICLE V.  TERMINATION  Section 5.1.Term.  This Agreement shall be
effective on the date hereof, and shall continue in full force and effect until
the ICG Service Period has fully expired.  Section 5.2.           Effect of Termination.  (a)           Upon termination of this Agreement,
all further obligations of ICG to provide, or Level 3 to purchase, services set
forth in Article II
hereunder shall terminate, except (i) any amounts incurred prior to termination
but not yet paid, and (ii) any liability for SLA remedies or for breach of any
of the covenants or any of the representations or warranties contained in this
Agreement.  (b)           Following any
termination of this Agreement, each party shall cooperate with the other to
transfer and/or retain all records, prepare and file Tax Returns and take all
other actions necessary to provide ICG and Level 3 and their respective
successors and assigns with sufficient information in the form requested by ICG
or Level 3, or their respective successors and assigns, as the case may be, to
make (if needed in the discretion of the party seeking such services)
alternative service arrangements substantially consistent with those
contemplated by this Agreement.  Section
5.3.           Termination of Particular
Services.This is a master agreement and
shall be construed as a separate and independent agreement for each and every
service provided under this Agreement. Any termination of any particular
service shall not affect the obligations under this Agreement with respect to
any other service.  ARTICLE VI.  MISCELLANEOUS  Section 6.1.           Incorporation of Article IX and X.  All terms and provisions contained in
Articles IX and X of the Purchase Agreement are incorporated herein by
reference to the same extent as if expressly set forth herein.  Section 6.2.           Waiver of Consequential Damages.Notwithstanding any provision of this Agreement
to the contrary, neither party shall be liable to the other party for any
special, incidental, indirect, punitive or consequential damages, or damages
for lost profits, lost income or lost revenue, or for costs of procurement of
replacement services, whether foreseeable or not, arising out of, or in
connection with such partys failure to perform its respective obligations
hereunder (whether arising out of transmission interruptions or problems, any
interruption or degradation of service or otherwise), whether occasioned by any
construction, reconstruction, relocation, repair or maintenance performed by,
or failed to be performed by, the other party or any other cause whatsoever,
including breach of contract, breach of warranty,  7 
   negligence, or strict liability, all claims for which
damages are hereby specifically waived. 
Nothing contained herein shall operate as a limitation on the right of
either party hereto to bring an action for damages against any third party,
including claims for indirect, special or consequential damages, based on any
acts or omissions of such third party.  Section
6.3.           Relationship of Parties; No
Beneficiaries or Assumption.  (a)Each
party shall act as independent contractors to the other party in the
performance of the Services hereunder, and nothing contained in this Agreement
shall be deemed to create any association, partnership, joint venture, or
relationship of principal and agent or master and servant between the parties
to this Agreement or any Affiliates or subsidiaries thereof, or to provide
either party with the right, power or authority, whether express or implied, to
create any such duty or obligation on behalf of the other party.  (b)           This Agreement shall not confer any
rights or remedies upon any person or entity other than the parties hereto and
their respective permitted successors and assigns.  Section 6.4.           Number Termination Notices.  Notwithstanding
any provision in the Purchase Agreement or this Agreement to the contrary, any
Number Termination Notice shall be deemed delivered on the date it is sent by
email to ICG at the following email addresses: 
rasport@icgcom.com.   [SIGNATURE
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   IN WITNESS WHEREOF, ICG and Level 3 have executed and
delivered this Agreement as of the day and year first written above.   ICG TELECOM GROUP,
  INC.By:Name:Title:LEVEL 3 COMMUNICATIONS, LLCBy:Name:Title:  9