LETTER OF TRANSMITTAL

                                  OFFER TO EXCHANGE

                  ALL OUTSTANDING 10% SENIOR DISCOUNT NOTES DUE 2008
                   FOR 10% SENIOR EXCHANGE DISCOUNT NOTES DUE 2008
                                          OF
                                  ICG SERVICES, INC.


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          THE EXCHANGE OFFER WILL EXPIRE AT 5:00 P.M., NEW YORK CITY TIME,
          ON JULY   , 1998 UNLESS EXTENDED (THE "EXPIRATION DATE").
          -----------------------------------------------------------------

                                     Deliver To:
                            Norwest Banks, Exchange Agent

By Registered or Certified Mail:   By Facsimile:  By Hand or Overnight Courier:
                                 (612) 667-4972 
         Norwest Banks                                     Norwest Banks
    Corporate Trust Section                           Corporate Trust Section
        P.O. Box 1517              Confirm by         NorthStar East Building
   Minneapolis MN 55480-1517       Telephone:       Sixth and Marquette Avenues
                                 (612) 667-4070      Minneapolis MN 55479-0113


               Delivery of this instrument to an address other than as set
          forth above or transmission of instructions via a facsimile
          number other than the one listed above will not constitute a
          valid delivery.  The instructions accompanying this Letter of
          Transmittal should be read carefully before this Letter of
          Transmittal is completed.

               The undersigned acknowledges that he or she has received and
          reviewed the Prospectus dated June     , 1998 (the "Prospectus")
                                             ----
          of ICG Services, Inc. (the "Issuer") and this Letter of
          Transmittal (the "Letter of Transmittal"), which together
          constitute (i) the Issuer's offer (the "Exchange Offer") to
          exchange its outstanding 10% Senior Discount Notes due 2008 (the
          "Old Notes"), of which an aggregate of $490,000,000 in principal
          amount at maturity is outstanding as of the date hereof, for an
          equal principal amount of newly issued 10% Senior Exchange
          Discount Notes due 2008 (the "New Notes").  The New Notes have
          been registered under the Securities Act of 1933, as amended (the
          "Securities Act"), pursuant to a Registration Statement of which
          the Prospectus is a part.  Old Notes may be tendered only in
          integral multiples of $1,000.  Other capitalized terms used but
          not defined herein have the meaning given to them in the
          Prospectus.

               This Letter of Transmittal is to be completed by a holder of
          Old Notes either if certificates are to be forwarded herewith or
          if a tender of certificates for Old Notes, if available, is to be
          made by book-entry transfer to the account maintained by the
          Exchange Agent at the Depository Trust Company (the "Book-Entry
          Transfer Facility") pursuant to the procedures set forth in "The
          Exchange Offers -- Book-Entry Transfer" section of the
          Prospectus.  Holders of Old Notes whose certificates are not
          immediately available, or who are unable to deliver their
          certificates or confirmation of the book-entry tender of their
          Old Notes into the Exchange Agent's account at the Book-Entry
          Transfer Facility (a "Book-Entry Confirmation") and all other
          documents required by this Letter of Transmittal to the Exchange


     


          Agent on or prior to the Expiration Date, must tender their Old
          Notes according to the guaranteed delivery procedures set forth
          in "The Exchange Offers -- Guaranteed Delivery Procedures"
          section of the Prospectus.  See Instruction 1.  Delivery of
          Documents to the Book-Entry Transfer Facility does not constitute
          delivery to the Exchange Agent.

               The term "Holder" with respect to the Exchange Offer means
          any person in whose name Old Notes are registered on the books of
          the Issuer or any other person who has obtained a properly
          completed bond power from the registered holder.  The undersigned
          has completed, executed and delivered this Letter of Transmittal
          to indicate the action the undersigned desires to take with
          respect to the Exchange Offer.  Holders who wish to tender their
          Old Notes must complete this letter in its entirety.

                    PLEASE READ THIS ENTIRE LETTER OF TRANSMITTAL
                         CAREFULLY BEFORE COMPLETING THE BOX

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                  DESCRIPTION OF 10% SENIOR DISCOUNT NOTES DUE 2008
          -----------------------------------------------------------------
                                                                 PRINCIPAL 
                                                                   AMOUNT  
               NAMES AND                       AGGREGATE          TENDERED 
            ADDRESS(ES) OF                     PRINCIPAL        (MUST BE IN
          REGISTERED HOLDERS                    AMOUNT            INTEGRAL 
           (PLEASE FILL IN,   CERTIFICATE    REPRESENTED BY    MULTIPLES OF
              IF BLANK)         NUMBER(S)    CERTIFICATE(S)       $1,000)* 
          -----------------------------------------------------------------

                              ---------------------------------------------

                              ---------------------------------------------

                              ---------------------------------------------

                              ---------------------------------------------

                              ---------------------------------------------

                              ---------------------------------------------
                                TOTAL
          -----------------------------------------------------------------

          *  Unless indicated in the column labeled "Principal Amount
             Tendered," any tendering Holder of 10% Senior Discount Notes
             due 2008 will be deemed to have tendered the entire aggregate
             principal amount represented by the column labeled "Aggregate
             Principal Amount Represented by Certificate(s)."

             If the space provided above is inadequate, list the
             certificate numbers and principal amounts on a separate signed
             schedule and affix the list to this Letter of Transmittal.

             The minimum permitted tender is $1,000 in principal amount of
             10% Senior Discount Notes due 2008.  All other tenders must be
             in integral multiples of $1,000.
          -----------------------------------------------------------------

          [ ]  CHECK HERE IF TENDERED OLD NOTES ARE ENCLOSED HEREWITH.
          [ ]  CHECK HERE IF TENDERED OLD NOTES ARE BEING DELIVERED BY BOOK-
               ENTRY TRANSFER MADE TO THE ACCOUNT MAINTAINED BY THE
               EXCHANGE AGENT WITH DTC AND COMPLETE THE FOLLOWING (FOR USE
               BY ELIGIBLE INSTITUTIONS (AS HEREINAFTER DEFINED) ONLY):
               Name of Tendering Institution
                                            -------------------------------
               Account Number
                             ----------------------------------------------
               Transaction Code Number
                                      -------------------------------------

                                      -2- 
     


          [ ]  CHECK HERE IF TENDERED OLD NOTES ARE BEING DELIVERED
               PURSUANT TO A NOTICE OF GUARANTEED DELIVERY ENCLOSED
               HEREWITH AND COMPLETE THE FOLLOWING (FOR USE BY ELIGIBLE
               INSTITUTIONS ONLY):
               Name(s) of Registered Old Noteholder(s)
                                                      ---------------------
               Date of Execution of Notice of Guaranteed Delivery
                                                                 ----------
               Window Ticket Number (if available)
                                                  -------------------------
               Name of Institution which Guaranteed Delivery
                                                            ---------------
               Account Number (if delivered by book-entry transfer)
                                                                   --------


          [COLUMN 1]:
          -----------------------------------------------------------------
                            SPECIAL ISSUANCE INSTRUCTIONS
                            (See Instructions 4, 5 and 6)

          To be completed ONLY (i) if certificates for Old Notes not
          tendered, or New Notes issued in exchange for Old Notes accepted
          for exchange, are to be issued in the name of someone other than
          the undersigned, or (ii) if Old Notes tendered by book-entry
          transfer which are not exchanged are to be returned by credit to
          an account maintained at Depository Trust Company ("DTC").


          Issue certificate(s) to:

          Name
              -------------------------------------------------------------
                                    (Please Print)

          Address
                 ----------------------------------------------------------

          -----------------------------------------------------------------
                                  (Include Zip Code)


          -----------------------------------------------------------------
                     (Tax Identification or Social Security No.)


          Credit Old Notes not exchanged and delivered by book-entry
          transfer to the DTC account set forth below:


          ------------------------------
          DTC Account Number
          -----------------------------------------------------------------

          [COLUMN 2]:
          -----------------------------------------------------------------
                            SPECIAL DELIVERY INSTRUCTIONS
                            (See Instructions 4, 5 and 6)

          To be completed ONLY if certificates for Old Notes not tendered,
          or New Notes issued in exchange for Old Notes accepted for
          exchange, are to be sent to someone other than the undersigned,
          or to the undersigned at an address other than that shown above.

          Mail to:

          Name
              -------------------------------------------------------------
                                    (Please Print)

          Address
                 ----------------------------------------------------------

          -----------------------------------------------------------------
                                  (Include Zip Code)



          -----------------------------------------------------------------
                     (Tax Identification or Social Security No.)

          -----------------------------------------------------------------


                                      -3-
          


          Ladies and Gentlemen:

               Subject to the terms and conditions of the Exchange Offer,
          the undersigned hereby tenders to the Issuer the principal amount
          of Old Notes indicated above.  Subject to and effective upon the
          acceptance for exchange of the principal amount of Old Notes
          tendered in accordance with this Letter of Transmittal, the
          undersigned sells, assigns and transfers to, or upon the order
          of, the Issuer all right, title and interest in and to the Old
          Notes tendered hereby.  The undersigned hereby irrevocably
          constitutes and appoints the Exchange Agent its agent and attorney-in-
          fact (with full knowledge that the Exchange Agent also acts as
          the agent of the Issuer) with respect to the tendered Old Notes
          with full power of substitution to (i) deliver certificates for
          such Old Notes, or transfer ownership of such Old Notes on the
          account books maintained by DTC, to the Issuer and deliver all
          accompanying evidences of transfer and authenticity to, or upon
          the order of, the Issuer and (ii) present such Old Notes for
          transfer on the books of the Issuer and receive all benefits and
          otherwise exercise all rights of beneficial ownership of such Old
          Notes, all in accordance with the terms of the Exchange Offer. 
          The power of attorney granted in this paragraph shall be deemed
          to be irrevocable and coupled with an interest.

               The undersigned hereby represents and warrants that he or
          she has full power and authority to tender, sell, assign and
          transfer the Old Notes tendered hereby and that the Issuer will
          acquire good and unencumbered title thereto, free and clear of
          all liens, restrictions, charges and encumbrances and not subject
          to any adverse claim, when the same are acquired by the Issuer. 
          The undersigned hereby further represents that (i) any New Notes
          acquired in exchange for Old Notes tendered hereby will have been
          acquired in the ordinary course of business of the person
          receiving such New Notes, whether or not the undersigned, (ii)
          neither the undersigned nor any such other person is engaging in
          or intends to engage in a distribution of the New Notes, (iii)
          neither the Holder nor any such other person has an arrangement
          or understanding with any person to participate in the
          distribution of such New Notes and (iv) neither the Holder nor
          any such other person is an "affiliate," as defined in Rule 405
          under the Securities Act, of the Issuer.

               The undersigned also acknowledges that this Exchange Offer
          is being made in reliance upon interpretations contained in
          letters issued to third parties by the staff of the Securities
          and Exchange Commission (the "SEC") that the New Notes issued in
          exchange for the Old Notes pursuant to the Exchange Offer may be
          offered for resale, resold and otherwise transferred by holders
          thereof (other than any such holder that is an "affiliate" of the
          Issuer within the meaning of Rule 405 under the Securities Act),
          without compliance with the registration and prospectus delivery
          provisions of the Securities Act, provided that such New Notes
          are acquired in the ordinary course of such holders' business and
          such holders are not engaging in and do not intend to engage in a
          distribution of the New Notes and have no arrangement or
          understanding with any person to participate in distribution of
          such New Notes.  If the undersigned is not a broker-dealer, the
          undersigned represents that it is not engaged in, and does not
          intend to engage in, a distribution of New Notes.  If the
          undersigned is a broker-dealer that will receive New Notes for
          its own account in exchange for Old Notes that were acquired as a
          result of market-making activities or other trading activities,
          it acknowledges that it will deliver a prospectus in connection
          with any resale of such New Notes; however, by so acknowledging
          and by delivering a prospectus, the undersigned will not be
          deemed to admit that it is an "underwriter" within the meaning of
          the Securities Act.

               The undersigned will, upon request, execute and deliver any
          additional documents deemed by the Exchange Agent or the Issuer
          to be necessary or desirable to complete the assignment, transfer
          and purchase of the Old Notes tendered hereby.

               For purposes of the Exchange Offer, the Issuer shall be
          deemed to have accepted validly tendered Old Notes when, as and
          if the Issuer has given oral or written notice thereof to the
          Exchange Agent.

               If any tendered Old Notes are not accepted for exchange
          pursuant to the Exchange Offer for any reason, certificates for
          any such unaccepted Old Notes will be returned, without expense,
          to the undersigned at the address shown below or at a different
          address as may be indicated herein under "Special Delivery
          Instructions" as promptly as practicable after the Expiration
          Date.

               All authority conferred or agreed to be conferred by this
          Letter of Transmittal shall survive the death, incapacity or
          dissolution of the undersigned, and every obligation of the
          undersigned under this Letter of Transmittal shall be binding
          upon the undersigned's heirs, personal representatives,
          successors and assigns.


                                      -4-
     

               The undersigned understands that tenders of Old Notes
          pursuant to the procedures described under the caption "The
          Exchange Offers -- Procedures for Tendering" in the Prospectus
          and in the instructions hereto will constitute a binding
          agreement between the undersigned and the Issuer upon the terms
          and subject to the conditions of the Exchange Offer.

               Unless otherwise indicated under "Special Issuance
          Instructions," please issue the certificates representing the New
          Notes issued in exchange for the Old Notes accepted for exchange
          and return any Old Notes not tendered or not exchanged, in the
          name(s) of the undersigned. Similarly, unless otherwise indicated
          under "Special Delivery Instructions," please send the
          certificates representing the New Notes issued in exchange for
          the Old Notes accepted for exchange and any certificates for Old
          Notes not tendered or not exchanged (and accompanying documents,
          as appropriate) to the undersigned at the address shown below the
          undersigned's signature(s).  In the event that both "Special
          Payment Instructions" and "Special Delivery Instructions" are
          completed, please issue the certificates representing the New
          Notes issued in exchange for the Old Notes accepted for exchange
          in the name(s) of, and return any Old Notes not tendered or not
          exchanged and send said certificates to, the person(s) so
          indicated.  The undersigned recognizes that the Issuer has no
          obligation pursuant to the "Special Payment Instructions" and
          "Special Delivery Instructions" to transfer any Old Notes from
          the name of the registered holder(s) thereof if the Issuer does
          not accept for exchange any of the Old Notes so tendered.

               Holders of Old Notes who wish to tender their Old Notes and
          (i) whose Old Notes are not immediately available, or (ii) who
          cannot deliver their Old Notes, this Letter of Transmittal or any
          other documents required hereby to the Exchange Agent prior to
          the Expiration Date (or who cannot comply with the book-entry
          transfer procedure on a timely basis), may tender their Old Notes
          according to the guaranteed delivery procedures set forth in the
          Prospectus under the caption "The Exchange Offers -- Guaranteed
          Delivery Procedures."  See Instruction 1 regarding the completion
          of this Letter of Transmittal, printed below.


                                      -5-
          


                           PLEASE SIGN HERE WHETHER OR NOT
                    OLD NOTES ARE BEING PHYSICALLY TENDERED HEREBY

          X
          -----------------------------------               ---------------
                                                                  Date     

          X
          -----------------------------------               ---------------
          Signature(s) of Registered Holder(s)                    Date     
               or Authorized Signatory

          Area Code and Telephone Number:
                                         --------------------

               The above lines must be signed by the registered holder(s)
          of Old Notes as their name(s) appear(s) on the Old Notes or by
          person(s) authorized to become registered holder(s) by a properly
          completed bond power from the registered holder(s), a copy of
          which must be transmitted with this Letter of Transmittal.  If
          Old Notes to which this Letter of Transmittal relate are held of
          record by two or more joint holders, then all such holders must
          sign this Letter of Transmittal.  If signature is by trustee,
          executor, administrator, guardian, attorney-in-fact, officer of a
          corporation or other person acting in a fiduciary or
          representative capacity, then such person must (i) set forth his
          or her full title below and (ii) unless waived by the Issuer,
          submit evidence satisfactory to the Issuer of such person's
          authority so to act.  See Instruction 4 regarding the completion
          of this Letter of Transmittal, printed below.


          Name(s): 
                   --------------------------------------------------------

          -----------------------------------------------------------------
                                    (Please Print)

          Capacity:
                    -------------------------------------------------------

          Address:
                    -------------------------------------------------------

                    -------------------------------------------------------
                                  (Include Zip Code)


                    Signature(s) Guaranteed by an Eligible Institution (as
                    hereinafter defined):
                    (If required by Instruction 4)


                    -------------------------------------------------------
                                (Authorized Signature)


                    -------------------------------------------------------
                                       (Title)


                    -------------------------------------------------------
                                    (Name of Firm)


                    Dated:                  , 1998
                           ----------------


                                      -6-
          


                                     INSTRUCTIONS

            FORMING PART OF THE TERMS AND CONDITIONS OF THE EXCHANGE OFFER


               1.   DELIVERY OF THIS LETTER OF TRANSMITTAL AND OLD NOTES. 
          The tendered Old Notes or any confirmation of a book-entry
          transfer (a "Book-Entry Confirmation"), as well as a properly
          completed and duly executed copy of this Letter of Transmittal or
          facsimile hereof and any other documents required by this Letter
          of Transmittal must be received by the Exchange Agent at its
          address set forth herein prior to 5:00 p.m., New York City time,
          on the Expiration Date.  The method of delivery of the tendered
          Old Notes, this Letter of Transmittal and all other required
          documents to the Exchange Agent is at the election and risk of
          the Holder and, except as otherwise provided below, the delivery
          will be deemed made only when actually received or confirmed by
          the Exchange Agent.  Instead of delivery by mail, it is
          recommended that the Holder use an overnight or hand delivery
          service.  In all cases, sufficient time should be allowed to
          assure delivery to the Exchange Agent before the Expiration Date. 
          No Letter of Transmittal or Old Notes should be sent to the
          Issuer.

               Holders who wish to tender their Old Notes and (i) whose Old
          Notes are not immediately available, or (ii) who cannot deliver
          their Old Notes, this Letter of Transmittal or any other
          documents required hereby to the Exchange Agent prior to the
          Expiration Date or (iii) who are unable to complete the procedure
          for book-entry transfer on a timely basis, must tender their Old
          Notes according to the guaranteed delivery procedures set forth
          in the Prospectus.  Pursuant to such procedure:  (i) such tender
          must be made by or through an Eligible Institution (as
          hereinafter defined); (ii) prior to the Expiration Date, the
          Exchange Agent must have received from the Eligible Institution a
          properly completed and duly executed Notice of Guaranteed
          Delivery (by facsimile transmission, mail or hand delivery)
          setting forth the name and address of the Holder of the Old
          Notes, the certificate number or numbers of such Old Notes and
          the principal amount of Old Notes tendered, stating that the
          tender is being made thereby and guaranteeing that, within five
          New York Stock Exchange trading days after the Expiration Date,
          this Letter of Transmittal (or facsimile hereof) together with
          the certificate(s) representing the Old Notes (or a Book-Entry
          Confirmation) and any other required documents will be deposited
          by the Eligible Institution with the Exchange Agent; and (iii)
          such properly completed and executed Letter of Transmittal (or
          facsimile hereof), as well as all other documents required by
          this Letter of Transmittal and the certificates(s) representing
          all tendered Old Notes (or a Book-Entry Confirmation) in proper
          form for transfer, must be received by the Exchange Agent within
          five New York Stock Exchange trading days after the Expiration
          Date, all as provided in the Prospectus under the caption "The
          Exchange Offers -- Guaranteed Delivery Procedures."  Any Holder
          of Old Notes who wishes to tender his or her Old Notes pursuant
          to the guaranteed delivery procedures described above must ensure
          that the Exchange Agent receives the Notice of Guaranteed
          Delivery prior to 5:00 p.m., New York City time, on the
          Expiration Date.  Upon request of the Exchange Agent, a Notice of
          Guaranteed Delivery will be sent to Holders who wish to tender
          their Old Notes according to the guaranteed delivery procedures
          set forth above.

               All questions as to the validity, form, eligibility
          (including time of receipt), acceptance of tendered Old Notes and
          withdrawal of tendered Old Notes will be determined by the Issuer
          in its sole discretion, which determination will be final and
          binding.  The Issuer reserves the absolute right to reject any
          and all Old Notes not properly tendered or any Old Notes the
          Issuer's acceptance of which would, in the opinion of counsel for
          the Issuer, be unlawful.  The Issuer also reserves the right to
          waive any irregularities or conditions of tender as to particular
          Old Notes.  The Issuer's interpretation of the terms and
          conditions of the Exchange Offer (including the instructions in
          this Letter of Transmittal) shall be final and binding on all
          parties.  Unless waived, any defects or irregularities in
          connection with tenders of Old Notes must be cured within such
          time as the Issuer shall determine.  Neither the Issuer, the
          Exchange Agent nor any other person shall be under any duty to
          give notification of defects or irregularities with respect to
          tenders of Old Notes, nor shall any of them incur any liability
          for failure to give such notification.  Tenders of Old Notes will
          not be deemed to have been made until such defects or
          irregularities have been cured or waived.  Any Old Notes received
          by the Exchange Agent that are not properly tendered and as to
          which the defects or irregularities have not been cured or waived
          will be returned by the Exchange Agent to the tendering Holders
          of Old Notes, unless otherwise provided in this Letter of
          Transmittal, as soon as practicable following the Expiration
          Date.

               2.   TENDER BY HOLDER.  Only a Holder of Old Notes may
          tender such Old Notes in the Exchange Offer.  Any beneficial
          holder of Old Notes who is not the registered holder and who
          wishes to tender should arrange with the registered holder to


                                      -7-
     


          execute and deliver this Letter of Transmittal on his behalf or
          must, prior to completing and executing this Letter of
          Transmittal and delivering his Old Notes, either make appropriate
          arrangements to register ownership of the Old Notes in such
          holder's name or obtain a properly completed bond power from the
          registered holder.

               3.   PARTIAL TENDERS.  Tenders of Old Notes will be accepted
          only in integral multiples of $1,000.  If less than the entire
          principal amount of any Old Notes is tendered, the tendering
          Holder should fill in the principal amount tendered in the third
          column of the box entitled "Description of 10% Senior Discount
          Notes due 2008" above.  The entire principal amount of Old Notes
          delivered to the Exchange Agent will be deemed to have been
          tendered unless otherwise indicated.  If the entire principal
          amount of all Old Notes is not tendered, then Old Notes for the
          principal amount of Old Notes not tendered and a certificate or
          certificates representing New Notes issued in exchange for any
          Old Notes accepted will be sent to the Holder at his or her
          registered address, unless a different address is provided in the
          appropriate box on this Letter of Transmittal, promptly after the
          Old Notes are accepted for exchange.

               4.   SIGNATURES ON THE LETTER OF TRANSMITTAL; BOND POWERS
          AND ENDORSEMENTS; GUARANTEE OF SIGNATURES.  If this Letter of
          Transmittal (or facsimile hereof) is signed by the record
          Holder(s) of the Old Notes tendered hereby, the signature must
          correspond with the name(s) as written on the face of the Old
          Notes without alteration, enlargement or any change whatsoever.

               If this Letter of Transmittal (or facsimile hereof) is
          signed by the registered holder or holders of Old Notes tendered
          and the certificate or certificates for New Notes issued in
          exchange therefor is to be issued (or any untendered principal
          amount of Old Notes is to be reissued) to the registered holder,
          the said holder need not and should not endorse any tendered Old
          Notes, nor provide a separate bond power.  In any other case,
          such holder must either properly endorse the Old Notes tendered
          or transmit a properly completed separate bond power with this
          Letter of Transmittal, with the signatures on the endorsement or
          bond power guaranteed by an Eligible Institution.

               If this Letter of Transmittal (or facsimile hereof) is
          signed by a person other than the registered holder or holders of
          any Old Notes listed, such Old Notes must be endorsed or
          accompanied by appropriate bond powers, in each case signed as
          the name of the registered holder or holders appears on the Old
          Notes.

               If this Letter of Transmittal (or facsimile hereof) or any
          Old Notes or bond powers are signed by trustees, executors,
          administrators, guardians, attorneys-in-fact, or officers of
          corporations or others acting in a fiduciary or representative
          capacity, such persons should so indicate when signing, and,
          unless waived by the Issuer, evidence satisfactory to the Issuer
          of their authority so to act must be submitted with this Letter
          of Transmittal.

               Endorsements on Old Notes or signatures on bond powers
          required by this Instruction 4 must be guaranteed by an Eligible
          Institution.

               Except as otherwise provided below, all signatures on this
          Letter of Transmittal must be guaranteed by a participant in a
          Recognized Signature Guarantee Medallion Program (an "Eligible
          Institution").  Signatures on this Letter of Transmittal need not
          be guaranteed if (a) this Letter of Transmittal is signed by the
          registered Holder(s) of the Old Notes tendered herewith and such
          Holder(s) have not completed the box set forth herein entitled
          "Special Payment Instructions" or the box entitled "Special
          Delivery Instructions," or (b) if such Old Notes are tendered for
          the account of an Eligible Institution.

               5.   SPECIAL PAYMENT AND DELIVERY INSTRUCTIONS.  Tendering
          Holders should indicate, in the applicable box or boxes, the name
          and address to which New Notes or substitute Old Notes for
          principal amounts not tendered or not accepted for exchange are
          to be issued or sent, if different from the name and address of
          the person signing this Letter of Transmittal.  In the case of
          issuance in a different name, the taxpayer identification or
          social security number of the person named must also be
          indicated.

               6.   TRANSFER TAXES.  The Issuer will pay all transfer
          taxes, if any, applicable to the exchange of Old Notes pursuant
          to the Exchange Offer.  If, however, certificates representing
          New Notes or Old Notes for principal amounts not tendered or
          accepted for exchange are to be delivered to, or are to be


                                      -8-
     


          registered or issued in the name of, any person other than the
          registered holder of the Old Notes tendered hereby, or if
          tendered Old Notes are registered in the name of any person other
          than the person signing this Letter of Transmittal, or if a
          transfer tax is imposed for any reason other than the exchange of
          Old Notes pursuant to the Exchange Offer, then the amount of any
          such transfer taxes (whether imposed on the registered holder or
          on any other persons) will be payable by the tendering holder. 
          If satisfactory evidence of payment of such taxes or exemption
          therefrom is not submitted with this Letter of Transmittal, the
          amount of such transfer taxes will be billed directly to such
          tendering holder.

               Except as provided in this Instruction 6, it will not be
          necessary for transfer tax stamps to be affixed to the Old Notes
          listed in this Letter of Transmittal.

               7.   WAIVER OF CONDITIONS.  The Issuer reserves the absolute
          right to amend, waive or modify specified conditions in the
          Exchange Offer in the case of any Old Notes tendered.

               8.   MUTILATED, LOST, STOLEN OR DESTROYED OLD NOTES.  Any
          tendering Holder whose Old Notes have been mutilated, lost,
          stolen or destroyed should contact the Exchange Agent at the
          address indicated herein for further instructions.

               9.   REQUESTS FOR ASSISTANCE OR ADDITIONAL COPIES. 
          Questions and requests for assistance and requests for additional
          copies of the Prospectus or this Letter of Transmittal may be
          directed to the Exchange Agent at the address specified in the
          Prospectus.  Holders may also contact their broker, dealer,
          commercial bank, trust company or other nominee for assistance
          concerning the Exchange Offer.


                            (DO NOT WRITE IN SPACE BELOW)

                        =====================================
                          CERTIFICATE  OLD NOTES  OLD NOTES
                          SURRENDERED  TENDERED   ACCEPTED
                        -------------------------------------

                        -------------------------------------

                        =====================================


          Delivery
          Prepared by              Checked By        Date                  
                     -------------           -------     ------------------


                                      -9-
          


                          NOTICE OF GUARANTEED DELIVERY FOR

                                  ICG SERVICES, INC.


               This form or one substantially equivalent hereto must be
          used to accept the Exchange Offer of ICG Services, Inc. (the
          "Issuer") made pursuant to the Prospectus, dated June    , 1998 
                                                                ---
          (the "Prospectus"), if certificates for Old Notes of the Issuer
          are not immediately available or if the procedure for book-entry
          transfer cannot be completed on a timely basis or time will not
          permit all required documents to reach the Exchange Agent prior
          to 5:00 p.m., New York City time, on the Expiration Date of the
          Exchange Offer.  Such form may be delivered or transmitted by
          telegram, telex, facsimile transmission, mail or hand delivery to
          Norwest Banks (the "Exchange Agent") as set forth below.  In
          addition, in order to utilize the guaranteed delivery procedure
          to tender Old Notes pursuant to the Exchange Offer, a completed,
          signed and dated Letter of Transmittal (or facsimile thereof)
          must also be received by the Exchange Agent prior to 5:00 p.m.,
          New York City time, on the Expiration Date.  Capitalized terms
          not defined herein are defined in the Prospectus.

                                     Deliver To:
                            Norwest Banks, Exchange Agent

    By Registered Mail or          By Facsimile:        By Hand or Overnight
        Certified Mail:           (612) 667-4972              Courier:
         Norwest Banks                                     Norwest Banks
    Corporate Trust Section                           Corporate Trust Section
         P.O. Box 1517              Confirm by        NorthStar East Building
   Minneapolis MN 55480-1517        Telephone:     Sixth and Marquette Avenues
                                  (612) 667-4070    Minneapolis MN 55479-0113


               Delivery of this instrument to an address other than as set
          forth above, or transmission of instructions via facsimile other
          than as set forth above, will not constitute a valid delivery.


          Ladies and Gentlemen:

               Upon the terms and conditions set forth in the Prospectus
          and the accompanying Letter of Transmittal, the undersigned
          hereby tenders to the Issuer the principal amount at maturity of
          Old Notes set forth below, pursuant to the guaranteed delivery
          procedure described in "The Exchange Offers -- Guaranteed
          Delivery Procedures" section of the Prospectus.  By so tendering,
          the undersigned hereby does make, at and as of the date hereof,
          the representations and warranties of a tendering holder of Old
          Notes set forth in the Letter of Transmittal.
                    
          Principal Amount of Old                If Old Notes will be delivered
          Notes Tendered:                        by book-entry transfer to
                                                 Depository Trust Company, 
          $                                      provide account number.
           --------------------------

          Certificate Nos. (if available):

          ---------------------------

          Total Principal Amount Represented
          by Old Notes Certificate(s):

          $                                      Account Number
           --------------------------                          ----------------

          ---------------------------------------------------------------------


     

               ALL AUTHORITY HEREIN CONFERRED OR AGREED TO BE CONFERRED
          SHALL SURVIVE THE DEATH OR INCAPACITY OF THE UNDERSIGNED AND
          EVERY OBLIGATION OF THE UNDERSIGNED HEREUNDER SHALL BE BINDING
          UPON THE HEIRS, PERSONAL REPRESENTATIVES, SUCCESSORS AND ASSIGNS
          OF THE UNDERSIGNED.
          -----------------------------------------------------------------

                                   PLEASE SIGN HERE

          X
           ------------------------------     ------------
          X
           ------------------------------     ------------
              Signatures of Owner(s)              Date
              or Authorized Signatory

            Area Code and Telephone
            Number:
                    --------------------

               Must be signed by the holder(s) of Old Notes as their
          name(s) appear(s) on certificates for Old Notes or on a security
          position listing, or by person(s) authorized to become registered
          holder(s) by endorsement and documents transmitted with this
          Notice of Guaranteed Delivery.  If signature is by a trustee,
          executor, administrator, guardian, attorney-in-fact, officer or
          other person acting in a fiduciary or representative capacity,
          such person must set forth his or her full title below.

                         Please print name(s) and address(es)

          Name(s):
                    -------------------------------------------------------

                    -------------------------------------------------------

                    -------------------------------------------------------
          Capacity:
                    -------------------------------------------------------
          Address(es):
                    -------------------------------------------------------

                    -------------------------------------------------------

                                      GUARANTEE

               The undersigned, a member of a registered national
          securities exchange, or a member of the National Association of
          Securities Dealers, Inc., or a commercial bank or trust company
          having an officer or correspondent in the United States, hereby
          guarantees that the certificates representing the principal
          amount of Old Notes tendered hereby in proper form or transfer,
          or timely confirmation of the book-entry transfer of such Old
          Notes into the Exchange Agent's account at Depository Trust
          Company pursuant to the procedures set forth in "The Exchange
          Offers -- Guaranteed Delivery Procedures" section of the
          Prospectus, together with a properly completed and duly executed
          Letter of Transmittal (or a manually signed facsimile thereof)
          with any required signature guarantee and any other documents
          required by the Letter of Transmittal, will be received by the
          Exchange Agent at the address set forth above, no later than five
          New York Stock Exchange trading days after the date of execution
          hereof.

          ------------------------------     ------------------------------
                 Name of Firm                     Authorized Signature


          ------------------------------     ------------------------------
                    Address                               Title

                                             Name:
          ------------------------------          -------------------------
                                Zip Code            (Please Type or Print)

          Area Code
          and Tel. No.                       Dated:
                      -----------------            ------------------------

          NOTE:  DO NOT SEND CERTIFICATES FOR OLD NOTES WITH THIS FORM. 
          CERTIFICATES FOR OLD NOTES SHOULD ONLY BE SENT WITH YOUR LETTER
          OF TRANSMITTAL.


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