AMENDMENT NO. 1 TO THE
                                CREDIT AGREEMENT


                                                 Dated as of September 30, 1999.

     AMENDMENT NO. 1 TO THE CREDIT  AGREEMENT  dated as of August 12, 1999, (the
"Credit  Agreement";  the  capitalized  terms defined  therein and not otherwise
defined herein being used herein as therein defined) among ICG Equipment,  Inc.,
a  Colorado  corporation  ("ICG  Equipment"),  ICG  NetAhead,  Inc.,  a Delaware
corporation ("ICG NetAhead" and, together with ICG Equipment,  the "Borrowers"),
ICG Services,  Inc., as Parent,  certain  Initial  Lender Parties party thereto,
Morgan  Stanley Senior  Funding,  Inc., as Sole  Book-Runner  and Lead Arranger,
Royal Bank of Canada, as Collateral Agent and as  Administrative  Agent for such
Lender  Parties,   and  Bank  of  America,   N.A.  and  Barclays  Bank  Plc,  as
Co-Documentation Agents.

     PRELIMINARY STATEMENT:

     The Borrowers,  the Parent,  and the Required  Lenders have agreed to amend
the Credit Agreement as hereinafter set forth.

     SECTION  1.  Amendments  to Credit  Agreement.  The  Credit  Agreement  is,
effective  as of  the  date  hereof  and  subject  to  the  satisfaction  of the
conditions precedent set forth in Section 2, hereby amended as follows:

     (a) The  definition  of "EBITDA" in Section 1.01 is amended in full to read
as follows:

               ""EBITDA" means,  with respect to any Person for any period,  the
          sum of the  following,  determined  on a  Consolidated  basis  without
          duplication,  in accordance with GAAP: (a) net income (or net loss) of
          such Person and its  Subsidiaries  for such period plus (b) the sum of
          the following (in each case, to the extent deducted in determining net
          income) (i) income and  franchise  tax expenses of such Person and its
          Subsidiaries,   (ii)   interest   expense  of  such   Person  and  its
          Subsidiaries,  (iii)  amortization,  depreciation  and other  non-cash
          charges  and (iv) any  non-recurring  extraordinary  losses,  less (c)
          interest  income  of  such  Person  and  its   Subsidiaries   and  any
          non-recurring extraordinary gains (including, without limitation, with
          respect to any person, any gain recognized as a result of any Add-Back
          Amount  (as  such  term is  hereinafter  defined)  being  subsequently
          recognized as income on any  statement of income of such Person).  For
          purposes  of all EBITDA  calculations  for any Person  relating to the
          third fiscal  quarter of 1999,  an amount shall be added to net income
          equal  to the  amount  of any  provision  for  uncollectable  accounts
          receivable  which relate to tandem switching and common transport fees
          made by such  Person  in its  statement  of  income  for such  period;

<PAGE>
                                       2


          provided that such amount shall not, in any event,  exceed $50,000,000
          (the "Provision  Add-Back Amount").  In addition,  for purposes of all
          EBITDA  calculations  for any Person  relating to the third and fourth
          fiscal   quarters  of  1999,   all  amounts   billed  for   reciprocal
          compensation  relating to tandem  switching and common  transport fees
          during  such  periods  shall be  considered  as net income even if not
          recognized  as income on the  statement  of income of such  Person for
          such period (such amounts being the "Net Income Add-Back Amounts" and,
          together with the Provision Add-Back Amount, the "Add-Back  Amounts");
          provided that the Net Income Add-Back  Amounts shall not, in any event
          exceed  $20,000,000 in respect of the third fiscal quarter of 1999 and
          $25,000,000 in respect of the fourth fiscal quarter of 1999."

     (b) The  definition of "Revenue" in Section 1.01 is amended in full to read
as follows:

               ""Revenue"  means, for any period,  Consolidated  revenues of ICG
          and its  Subsidiaries  for such period as determined on a Consolidated
          basis in accordance with GAAP. For the purpose of all  calculations of
          Revenue  for the third and fourth  fiscal  quarters  of 1999,  Revenue
          shall also  include all  amounts  billed for  reciprocal  compensation
          relating to tandem  switching  and common  transport  fees during such
          periods even if not  recognized  as revenue on any statement of income
          for  such  periods;  provided  that  such  amounts  shall  not  exceed
          $20,000,000  for the third fiscal quarter of 1999 and  $25,000,000 for
          the fourth  fiscal  quarter of 1999.  Any item  included as Revenue by
          reason  only of the  immediately  preceding  sentence  shall  not,  if
          subsequently  recognized as revenue in any statement of income of such
          person,  be  considered  as  Revenue."

     SECTION  2.  Conditions  of  Effectiveness.  This  Amendment  shall  become
effective  as of the date first  above  written  when,  and only when,  the Lead
Arranger  shall have received  counterparts  of this  Amendment  executed by the
Borrowers,  the Parent,  and the Required  Lenders or, as to any of the Required
Lender Parties,  advice satisfactory to the Lead Arranger that such Lender Party
has executed this Amendment.

     SECTION 3.  Representations and Warranties of the Borrower.  The Parent and
each Borrower represent and warrant as follows:

     (a) Each Loan Party and each of its  Subsidiaries (i) is a corporation duly
organized,  validly  existing  and  in  good  standing  under  the  laws  of the
jurisdiction of its  incorporation,  (ii) is duly qualified and in good standing
as a foreign  corporation in each other  jurisdiction in which it owns or leases
property or in which the conduct of its business requires it to so qualify or be
licensed  except  where the  failure to so qualify or be  licensed  could not be
reasonably  likely to have a Material Adverse Effect and (iii) has all requisite
corporate power and authority (including,  without limitation,  all governmental
licenses,  permits  and  other  approvals)  to  own or  lease  and  operate  its
properties  and to carry on its business as now  conducted and as proposed to be
conducted.
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                                       3



     (b) The  execution,  delivery  and  performance  by each Loan Party of this
Amendment and the Transaction  Documents as amended hereby, to which it is or is
to be a party,  are within such Loan Party's  corporate  powers,  have been duly
authorized by all necessary  corporate  action,  and do not (i) contravene  such
Loan  Party's  charter  or  bylaws,  (ii)  violate  any  law,  rule,  regulation
(including,  without  limitation,  Regulation X of the Board of Governors of the
Federal  Reserve   System),   order,   writ,   judgment,   injunction,   decree,
determination  or award,  (iii)  conflict  with or result in the  breach  of, or
constitute a default or require any payment to be made under, any contract, loan
agreement, indenture, mortgage, deed of trust, lease or other instrument binding
on or  affecting  any  Loan  Party,  any of  its  Subsidiaries  or any of  their
properties  in such a manner as would be  reasonably  likely to have a  Material
Adverse  Effect or (iv)  except  for the  Liens  created  under the  Transaction
Documents,  result in or require the creation or  imposition of any Lien upon or
with  respect  to  any  of  the  properties  of  any  Loan  Party  or any of its
Subsidiaries.  No Loan Party or any of its  Subsidiaries  is in violation of any
such  law,  rule,  regulation,  order,  writ,  judgment,   injunction,   decree,
determination  or  award or in  breach  of any such  contract,  loan  agreement,
indenture,  mortgage, deed of trust, lease or other instrument, the violation or
breach of which could be reasonably likely to have a Material Adverse Effect.

     (c) No  authorization  or approval or other  action by, and no notice to or
filing with, any  governmental  authority or regulatory  body or any other third
party is required for the due  execution,  delivery or  performance  by any Loan
Party party of this Amendment or any of the  Transaction  Documents,  as amended
hereby, to which it is or is to be a party.

     (d) This  Amendment  has been duly executed and delivered by the Parent and
the Borrowers.  This Amendment and each of the other Transaction  Documents,  as
amended hereby, to which any Loan Party is a party are legal,  valid and binding
obligations of each Loan Party thereto,  enforceable  against such Loan Party in
accordance with their respective terms.

     (e) There is no  action,  suit,  investigation,  litigation  or  proceeding
affecting any Loan Party or any of its Subsidiaries, including any Environmental
Action,  pending  or  threatened  before  any  court,   governmental  agency  or
arbitrator that (i) could be reasonably likely to have a Material Adverse Effect
or (ii)  purports to affect the  legality,  validity or  enforceability  of this
Amendment or any of the other Transaction Documents as amended hereby.

     (f) The representations and warranties set forth in each of the Transaction
Documents are correct on and as of this date,  before and after giving effect to
this Amendment, as though made on and as of such date.

     (g) No event has occurred and is continuing that constitutes a Default.

     SECTION 4. Reference to and Effect on the Credit  Agreement,  the Notes and
the Transaction Documents. (a) On and after the effectiveness of this Amendment,
each  reference  in the  Credit  Agreement  to  "this  Agreement",  "hereunder",
"hereof" or words of like import  referring  to the Credit  Agreement,  and each
reference  in the  Notes  and each of the other  Transaction  Documents  to "the
Credit Agreement",  "thereunder", "thereof" or words of like import referring to
the Credit Agreement,  shall mean and be a reference to the Credit Agreement, as
amended by this Amendment.
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                                       4



     (b) The  Credit  Agreement,  the Notes  and each of the  other  Transaction
Documents, as specifically amended by this Amendment,  are and shall continue to
be in full  force  and  effect  and are  hereby  in all  respects  ratified  and
confirmed.  Without  limiting the  generality of the  foregoing,  the Collateral
Documents and all of the Collateral  described  therein do and shall continue to
secure the payment of all  Obligations of the Loan Parties under the Transaction
Documents, in each case as amended by this Amendment.

     (c) The execution,  delivery and effectiveness of this Amendment shall not,
except as expressly provided herein,  operate as a waiver of any right, power or
remedy of any Lender or the Agents under any of the Transaction  Documents,  nor
constitute a waiver of any provision of any of the Transaction Documents.

     SECTION 5. Consent of the Parent. The Parent, as guarantor under the Parent
Guaranty,  hereby consents to this Amendment and hereby confirms and agrees that
notwithstanding the effectiveness of this Amendment, the Parent Guaranty is, and
shall  continue  to be, in full  force and  effect  and is hereby  ratified  and
confirmed in all respects,  except that, on and after the  effectiveness of this
Amendment,  each  reference  in the Parent  Guaranty to the "Credit  Agreement",
"thereunder", "thereof" or words of like import shall mean and be a reference to
the Credit Agreement, as amended by this Amendment.

     SECTION 6. Costs and Expenses. The Borrowers agree jointly and severally to
pay on  demand  all  reasonable  costs  and  expenses  of the Lead  Arranger  in
connection  with  the  preparation,   execution,  delivery  and  administration,
modification  and  amendment of this  Amendment  and the other  instruments  and
documents  to  be  delivered  hereunder  (including,   without  limitation,  the
reasonable  fees and expenses of counsel for the Lead  Arranger)  in  accordance
with the terms of Section 9.04 of the Credit Agreement.

     SECTION 7. Execution in Counterparts. This Amendment may be executed in any
number of counterparts and by different parties hereto in separate counterparts,
each of which  when so  executed  shall be deemed to be an  original  and all of
which taken together shall  constitute but one and the same agreement.  Delivery
of an executed  counterpart  of a signature page to this Amendment by telecopier
shall be  effective  as  delivery  of a manually  executed  counterpart  of this
Amendment.
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                                       5



     SECTION  8.  Governing  Law.  This  Amendment  shall be  governed  by,  and
construed in accordance with, the laws of the State of New York.

                  IN WITNESS  WHEREOF,  the  parties  hereto  have  caused  this
Amendment to be executed by their respective officers thereunto duly authorized,
as of the date first above written.

                                         ICG EQUIPMENT, INC., as Borrower


                                         By /s/ Don Teague
                                           -------------------------------------
                                           Title:


                                         ICG NETAHEAD, INC., as Borrower


                                         By /s/ Don Teague
                                           -------------------------------------
                                           Title:


                                         ICG SERVICES, INC., as Parent Guarantor


                                         By /s/ Don Teague
                                           -------------------------------------
                                           Title:



<PAGE>

                                         MORGAN STANLEY SENIOR FUNDING, INC.,
                                         as Sole Book-Runner, Lead Arranger and
                                         Lender Party

                                         By /s/ T. Morgan Edwards II
                                           -------------------------------------
                                           Title: Vice President


<PAGE>



                                         ROYAL BANK OF CANADA,
                                         as Administrative Agent, Collateral
                                         Agent and Lender Party

                                         By /s/ K. K. Cornwell
                                           -------------------------------------
                                           Title: Managing Director


<PAGE>



                                         BANK OF AMERICA, N.A.,
                                         as Co-Documentation Agent and Lender
                                         Party

                                         By /s/ Julie A. Schell
                                           -------------------------------------
                                           Title: Vice President

<PAGE>




                                         BARCLAYS BANK PLC
                                         as Co-Documentation Agent and Lender
                                         Party

                                         By /s/ Daniele Jacovone
                                           -------------------------------------
                                           Title: Associate Director
<PAGE>


                           Initial Lenders

                                   PARIBAS, LOS ANGELES AGENCY

                                   By /s/ Darlynn Ernst Kitchner/Thomas G.Brandt
                                     -------------------------------------------
                                     Title: Vice President/Director



<PAGE>



                                         FINOVA CAPITAL CORPORATION

                                         By /s/ Jeffrey S. Kilrey
                                           -------------------------------------
                                           Title: Senior Vice President




<PAGE>




                                         FIRST UNION NATIONAL BANK

                                         By /s/ Mark L. Cook
                                           -------------------------------------
                                           Title: Senior Vice President



<PAGE>




                                         GENERAL ELECTRIC CAPITAL
                                         CORPORATION

                                         By /s/ John P. Waters
                                           -------------------------------------
                                           Title: Senior Vice President




<PAGE>




                                         IBM CREDIT

                                         By /s/ Thomas Curcio
                                           -------------------------------------
                                           Title: Manager of Credit



<PAGE>




                                         STEIN ROE FLOATING RATE LIMITED
                                         LIABILITY COMPANY

                                         By
                                           -------------------------------------
                                           Title:


<PAGE>




                                         STEIN ROE AND FARNHAM INCORPORATED
                                         AS AGENT FOR KEYPORT LIFE INSURANCE
                                         COMPANY

                                         By
                                           -------------------------------------
                                           Title:


<PAGE>



                                         STEIN ROE FARNHAM CLO 1 LTD.
                                         By:   Stein Roe & Farnham Incorporated
                                               as Portfolio Manager


                                         By
                                           -------------------------------------
                                           Title:


<PAGE>


                                         PILGRIM PRIME RATE TRUST
                                         By:   Pilgrim Investment, Inc., as its
                                                     investment manager

                                         By /s/ Michael Prince
                                           -------------------------------------
                                           Title: Vice President




<PAGE>


                                         KZH HIGHLAND-2 LLC

                                         By /s/ V. Conway
                                           -------------------------------------
                                           Title: Authorized Agent




<PAGE>


                                       BANK OF MONTREAL

                                       By /s/ Eric Scotfield
                                       -----------------------------------------
                                       Title: Director, Leveraged Debt Mangement



<PAGE>




                                         FRANKLIN FLOATING RATE TRUST

                                         By
                                           -------------------------------------
                                           Title:


<PAGE>




                                         ELT LTD.

                                         By
                                           -------------------------------------
                                           Title: