Exhibit 4.15  


                                 ICG HOLDINGS, INC.,
                                             as Issuer


                              ICG COMMUNICATIONS, INC.,
                                             as Guarantor


                                         and


                     NORWEST BANK COLORADO, NATIONAL ASSOCIATION,
                                             as Trustee





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

                                      Indenture

                              Dated as of March 11, 1997
                                                      
                              -------------------------


                        11 5/8% Senior Discount Notes due 2007


     

                                CROSS-REFERENCE TABLE
                                ---------------------



     TIA Sections                             Indenture Sections
     ------------                             ------------------

     <Section> 310(a)(1) . . . . . . . . . .         7.10
         (a)(2)  . . . . . . . . . . . . . .         7.10
         (b) . . . . . . . . . . . . . . . .         7.08
     <Section> 313(c)  . . . . . . . . . . .         7.06; 11.02
     <Section> 314(a)  . . . . . . . . . . .         4.18; 11.02
         (a)(4)  . . . . . . . . . . . . . .         4.17; 11.02
         (c)(1)  . . . . . . . . . . . . . .         11.03
         (c)(2)  . . . . . . . . . . . . . .         11.03
         (e) . . . . . . . . . . . . . . . .         11.04
     <Section> 315(b)  . . . . . . . . . . .         7.05; 11.02
     <Section> 316(a)(1)(A)  . . . . . . . .         6.05
         (a)(1)(B) . . . . . . . . . . . . .         6.04
         (b) . . . . . . . . . . . . . . . .         6.07
     <Section> 317(a)(1) . . . . . . . . . .         6.08
         (a)(2)  . . . . . . . . . . . . . .         6.09
     <Section> 318(a)  . . . . . . . . . . .         11.01
         (c) . . . . . . . . . . . . . . . .         11.01

     Note:     The Cross-Reference Table shall not for any purpose be deemed to
               be a part of the Indenture.


     


                                  TABLE OF CONTENTS 
                                  ----------------- 
                                                                          Page
                                                                          ----

     RECITALS OF THE COMPANY . . . . . . . . . . . . . . . . . . . . . . .   1

                                     ARTICLE ONE
                      DEFINITIONS AND INCORPORATION BY REFERENCE

       SECTION 1.01.  Definitions  . . . . . . . . . . . . . . . . . . . . .   1
       SECTION 1.02.  Incorporation by Reference of Trust Indenture Act  . .  22
       SECTION 1.03.  Rules of Construction  . . . . . . . . . . . . . . . .  22

                                     ARTICLE TWO
                                    THE SECURITIES

       SECTION 2.01.  Form and Dating  . . . . . . . . . . . . . . . . . . .  23
       SECTION 2.02.  Restrictive Legends  . . . . . . . . . . . . . . . . .  24
       SECTION 2.03.  Execution, Authentication and Denominations  . . . . .  26
       SECTION 2.04.  Registrar and Paying Agent . . . . . . . . . . . . . .  28
       SECTION 2.05.  Paying Agent to Hold Money in Trust  . . . . . . . . .  28
       SECTION 2.06.  Transfer and Exchange  . . . . . . . . . . . . . . . .  29
       SECTION 2.07.  Book-Entry Provisions for Global Securities  . . . . .  30
       SECTION 2.08.  Special Transfer Provisions  . . . . . . . . . . . . .  32
       SECTION 2.09.  Replacement Securities . . . . . . . . . . . . . . . .  34
       SECTION 2.10.  Outstanding Securities . . . . . . . . . . . . . . . .  35
       SECTION 2.11.  Temporary Securities . . . . . . . . . . . . . . . . .  36
       SECTION 2.12.  Cancellation . . . . . . . . . . . . . . . . . . . . .  36
       SECTION 2.13.  CUSIP Numbers  . . . . . . . . . . . . . . . . . . . .  36
       SECTION 2.14.  Defaulted Interest . . . . . . . . . . . . . . . . . .  36

                                    ARTICLE THREE
                                      REDEMPTION

       SECTION 3.01.  Right of Redemption  . . . . . . . . . . . . . . . . .  37
       SECTION 3.02.  Notices to Trustee . . . . . . . . . . . . . . . . . .  37
       SECTION 3.03.  Selection of Securities to Be Redeemed . . . . . . . .  38
       SECTION 3.04.  Notice of Redemption . . . . . . . . . . . . . . . . .  38
       SECTION 3.05.  Effect of Notice of Redemption . . . . . . . . . . . .  39
       SECTION 3.06.  Deposit of Redemption Price  . . . . . . . . . . . . .  39
       SECTION 3.07.  Payment of Securities Called for Redemption  . . . . .  40
       SECTION 3.08.  Securities Redeemed in Part  . . . . . . . . . . . . .  40

                                     ARTICLE FOUR
                                      COVENANTS

       SECTION 4.01.  Payment of Securities  . . . . . . . . . . . . . . . .  40
       SECTION 4.02.  Maintenance of Office or Agency  . . . . . . . . . . .  41
       SECTION 4.03.  Limitation on Indebtedness . . . . . . . . . . . . . .  41
       SECTION 4.04.  Limitation on Restricted Payments  . . . . . . . . . .  45
       SECTION 4.05.  Limitation on Dividend and Other Payment Restrictions
                    Affecting Restricted Subsidiaries  . . . . . . . . . . .  48
       SECTION 4.06.  Limitation on the Issuances and Sale of Capital Stock of
                    Restricted Subsidiaries  . . . . . . . . . . . . . . . .  50
       SECTION 4.07.  Limitation on Issuances of Guarantees by Restricted
                    Subsidiaries . . . . . . . . . . . . . . . . . . . . . .  50
       SECTION 4.08.  Limitation on Transactions with Shareholders and
                    Affiliates . . . . . . . . . . . . . . . . . . . . . . .  51
       SECTION 4.09.  Limitation on Liens  . . . . . . . . . . . . . . . . .  52
       SECTION 4.10.  Limitation on Sale-Leaseback Transactions  . . . . . .  53
       SECTION 4.11.  Limitation on Asset Sales  . . . . . . . . . . . . . .  54
       SECTION 4.12.  Repurchase of Securities upon a Change of Control  . .  55
       SECTION 4.13.  Existence  . . . . . . . . . . . . . . . . . . . . . .  55
       SECTION 4.14.  Payment of Taxes and Other Claims  . . . . . . . . . .  55
       SECTION 4.15.  Maintenance of Properties and Insurance  . . . . . . .  55
       SECTION 4.16.  Notice of Defaults . . . . . . . . . . . . . . . . . .  56
       SECTION 4.17.  Compliance Certificates  . . . . . . . . . . . . . . .  56
       SECTION 4.18.  Commission Reports and Reports to Holders  . . . . . .  57
       SECTION 4.19.  Waiver of Stay, Extension or Usury Laws  . . . . . . .  57

                                     ARTICLE FIVE
                                SUCCESSOR CORPORATION

       SECTION 5.01.  When Company and Guarantor May Merge, Etc. . . . . . .  58
       SECTION 5.02.  Successor Substituted  . . . . . . . . . . . . . . . .  59

                                     ARTICLE SIX
                                 DEFAULT AND REMEDIES

       SECTION 6.01.  Events of Default  . . . . . . . . . . . . . . . . . .  59
       SECTION 6.02.  Acceleration . . . . . . . . . . . . . . . . . . . . .  61
       SECTION 6.03.  Other Remedies . . . . . . . . . . . . . . . . . . . .  61
       SECTION 6.04.  Waiver of Past Defaults  . . . . . . . . . . . . . . .  62
       SECTION 6.05.  Control by Majority  . . . . . . . . . . . . . . . . .  62
       SECTION 6.06.  Limitation on Suits  . . . . . . . . . . . . . . . . .  62
       SECTION 6.07.  Rights of Holders to Receive Payment . . . . . . . . .  63
       SECTION 6.08.  Collection Suit by Trustee . . . . . . . . . . . . . .  63
       SECTION 6.09.  Trustee May File Proofs of Claim . . . . . . . . . . .  63
       SECTION 6.10.  Priorities . . . . . . . . . . . . . . . . . . . . . .  64
       SECTION 6.11.  Undertaking for Costs  . . . . . . . . . . . . . . . .  64
       SECTION 6.12.  Restoration of Rights and Remedies . . . . . . . . . .  64
       SECTION 6.13.  Rights and Remedies Cumulative . . . . . . . . . . . .  65
       SECTION 6.14.  Delay or Omission Not Waiver . . . . . . . . . . . . .  65

                                    ARTICLE SEVEN
                                       TRUSTEE

       SECTION 7.01.  General  . . . . . . . . . . . . . . . . . . . . . . .  65
       SECTION 7.02.  Certain Rights of Trustee  . . . . . . . . . . . . . .  65
       SECTION 7.03.  Individual Rights of Trustee . . . . . . . . . . . . .  67
       SECTION 7.04.  Trustee's Disclaimer . . . . . . . . . . . . . . . . .  67
       SECTION 7.05.  Notice of Default  . . . . . . . . . . . . . . . . . .  67
       SECTION 7.06.  Reports by Trustee to Holders  . . . . . . . . . . . .  67
       SECTION 7.07.  Compensation and Indemnity . . . . . . . . . . . . . .  67
       SECTION 7.08.  Replacement of Trustee . . . . . . . . . . . . . . . .  68
       SECTION 7.09.  Successor Trustee by Merger, Etc.  . . . . . . . . . .  69
       SECTION 7.10.  Eligibility  . . . . . . . . . . . . . . . . . . . . .  69
       SECTION 7.11.  Money Held in Trust  . . . . . . . . . . . . . . . . .  69
       SECTION 7.12.  Withholding Taxes  . . . . . . . . . . . . . . . . . .  69

                                    ARTICLE EIGHT
                                DISCHARGE OF INDENTURE

       SECTION 8.01.  Termination of Company's Obligations . . . . . . . . .  70
       SECTION 8.02.  Defeasance and Discharge of Indenture  . . . . . . . .  71
       SECTION 8.03.  Defeasance of Certain Obligations  . . . . . . . . . .  73
       SECTION 8.04.  Application of Trust Money . . . . . . . . . . . . . .  75
       SECTION 8.05.  Repayment to Company . . . . . . . . . . . . . . . . .  75
       SECTION 8.06.  Reinstatement  . . . . . . . . . . . . . . . . . . . .  75
       SECTION 8.07.  Insiders . . . . . . . . . . . . . . . . . . . . . . .  76

                                     ARTICLE NINE
                         AMENDMENTS, SUPPLEMENTS AND WAIVERS

       SECTION 9.01.  Without Consent of Holders . . . . . . . . . . . . . .  76
       SECTION 9.02.  With Consent of Holders  . . . . . . . . . . . . . . .  77
       SECTION 9.03.  Revocation and Effect of Consent . . . . . . . . . . .  78
       SECTION 9.04.  Notation on or Exchange of Securities  . . . . . . . .  78
       SECTION 9.05.  Trustee to Sign Amendments, Etc. . . . . . . . . . . .  79
       SECTION 9.06.  Conformity with Trust Indenture Act  . . . . . . . . .  79

                                     ARTICLE TEN
                               GUARANTEE OF SECURITIES

       SECTION 10.01.  Security Guarantee  . . . . . . . . . . . . . . . . .  79
       SECTION 10.02.  Obligations Unconditional . . . . . . . . . . . . . .  80
       SECTION 10.03.  Notice to Trustee . . . . . . . . . . . . . . . . . .  81
       SECTION 10.04.  This Article Not to Prevent Events of Default . . . .  81
       SECTION 10.05.  Net Worth Limitation  . . . . . . . . . . . . . . . .  81

                                    ARTICLE ELEVEN
                                    MISCELLANEOUS

       SECTION 11.01.  Trust Indenture Act of 1939 . . . . . . . . . . . . .  81
       SECTION 11.02.  Notices . . . . . . . . . . . . . . . . . . . . . . .  82
       SECTION 11.03.  Certificate and Opinion as to Conditions Precedent  .  83
       SECTION 11.04.  Statements Required in Certificate or Opinion . . . .  83
       SECTION 11.05.  Rules by Trustee, Paying Agent or Registrar . . . . .  84
       SECTION 11.06.  Payment Date Other Than a Business Day  . . . . . . .  84
       SECTION 11.07.  Governing Law; Submission to Jurisdiction . . . . . .  84
       SECTION 11.08.  No Adverse Interpretation of Other Agreements . . . .  84
       SECTION 11.09.  No Recourse Against Others  . . . . . . . . . . . . .  84
       SECTION 11.10.  Successors  . . . . . . . . . . . . . . . . . . . . .  85
       SECTION 11.11.  Duplicate Originals . . . . . . . . . . . . . . . . .  85
       SECTION 11.12.  Separability  . . . . . . . . . . . . . . . . . . . .  85
       SECTION 11.13.  Table of Contents, Headings, Etc. . . . . . . . . . .  85

     EXHIBIT A    Form of Security   . . . . . . . . . . . . . . . . . . . . A-1
     EXHIBIT B    Form of Certificate  . . . . . . . . . . . . . . . . . . . B-1
     EXHIBIT C    Form of Certificate to Be Delivered in Connection with
                    Transfers Pursuant to Regulation S   . . . . . . . . . . C-1
     EXHIBIT D    Form of Certificate to Be Delivered in Connection with
                    Transfers to Non-QIB Accredited Investors  . . . . . . . D-1


     ----------------------------
     Note:        The Table of Contents shall not for any purposes be deemed to
                  be a part of the Indenture.


     


              INDENTURE, dated as of March 11, 1997, among ICG HOLDINGS, INC.,
     a Colorado corporation, as Issuer (the "Company"), ICG COMMUNICATIONS,
                                             -------
     INC., a Delaware corporation, as Guarantor (the "Guarantor"), and NORWEST 
                                                      ---------
     BANK COLORADO, NATIONAL ASSOCIATION, as Trustee (the "Trustee").
                                                           -------

                               RECITALS OF THE COMPANY

                   The Company has duly authorized the execution and delivery
     of this Indenture to provide for the initial original issuance of
     $176,000,000 aggregate principal amount at maturity of the Company's 11
     5/8% Senior Discount Notes due 2007 (the "Securities"), and the issuance
                                               ----------
     from time to time of additional Securities, issuable as provided in this
     Indenture.  All things necessary to make this Indenture a valid agreement
     of the Company and the Guarantor, in accordance with its terms, have been
     done, and the Company and the Guarantor have done all things necessary to
     make the Securities, when executed by the Company and the Guarantor and
     authenticated and delivered by the Trustee hereunder and duly issued by the
     Company, the valid obligations of the Company and the Guarantor as
     hereinafter provided.

              This Indenture will, upon the effectiveness of the registration
     statement provided for under the Registration Rights Agreement, be subject
     to, and governed by, the provisions of the Trust Indenture Act of 1939, as
     amended, that are required to be a part of and to govern indentures
     qualified under the Trust Indenture Act of 1939, as amended.

              For and in consideration of the premises and the purchase of the
     Securities by the Holders thereof, it is mutually covenanted and agreed,
     for the equal and proportionate benefit of all Holders, as follows.


                                     ARTICLE ONE
                      DEFINITIONS AND INCORPORATION BY REFERENCE

               SECTION 1.01.  Definitions.
                              -----------

               "Accreted Value" means, for any Specified Date, the amount
     provided below for each $1,000 principal amount at maturity of Securities: 

               (i)  if the Specified Date occurs on one of the following dates
          (each a "Semi-Annual Accrual Date"), the Accreted Value will equal the
                  ------------------------
          amount set forth below for such Semi-Annual Accrual Date: 

               SEMI-ANNUAL ACCRUAL DATE  ACCRETED VALUE
               ------------------------  ---------------
                    March 11, 1997         $567.660
                         
                September 15, 1997         $601.410
                         
                    March 15, 1998         $636.366
                         
                September 15, 1998         $673.355
                         
                    March 15, 1999         $712.493
                         
                September 15, 1999         $753.907
                         
                    March 15, 2000         $797.727
                         
                September 15, 2000         $844.095
                         
                    March 15, 2001         $893.157
                         
                September 15, 2001         $945.072
                         
                    March 15, 2002       $1,000.000

              (ii) if the Specified Date occurs before the first Semi-Annual
         Accrual Date, the Accreted Value will equal the sum of (a) the
         original issue price and (b) an amount equal to the product of (1) the
         Accreted Value for the first Semi-Annual Accrual Date less the
         original issue price multiplied by (2) a fraction, the numerator of
         which is the number of days from the issue date of the Securities to
         the Specified Date, using a 360-day year of twelve 30-day months, and
         the denominator of which is the number of days elapsed from the issue
         date of the Securities to the first Semi-Annual Accrual Date, using a
         360-day year of twelve 30-day months; 

              (iii)     if the Specified Date occurs between two Semi-Annual
         Accrual Dates, the Accreted Value will equal the sum of (a) the
         Accreted Value for the Semi-Annual Accrual Date immediately preceding
         such Specified Date and (b) an amount equal to the product of (1) the
         Accreted Value for the immediately following Semi-Annual Accrual Date
         less the Accreted Value for the immediately preceding Semi-Annual
         Accrual Date multiplied by (2) a fraction, the numerator of which is
         the number of days from the immediately preceding Semi-Annual Accrual
         Date to the Specified Date, using a 360-day year of twelve 30-day
         months, and the denominator of which is 180; or 

              (iv) if the Specified Date occurs after the last Semi-Annual
         Accrual Date, the Accreted Value will equal $1,000. 

              "Acquired Indebtedness" has the meaning provided in
     Section 4.03(a).

              "Adjusted Consolidated Net Income" means, for any period, the
     aggregate net income (or loss) of the Guarantor and its Restricted
     Subsidiaries for such period determined in conformity with GAAP; provided
     that the following items shall be excluded in computing Adjusted
     Consolidated Net Income (without duplication): (i) the net income of any
     Person (other than net income attributable to a Restricted Subsidiary) in
     which any Person (other than the Guarantor or any of its Restricted
     Subsidiaries) has a joint interest and the net income of any Unrestricted
     Subsidiary, except to the extent of the amount of dividends or other
     distributions actually paid to the Guarantor or any of its Restricted
     Subsidiaries by such other Person or such Unrestricted Subsidiary during
     such period; (ii) solely for the purposes of calculating the amount of
     Restricted Payments that may be made pursuant to clause (C) of the first
     paragraph of Section 4.04 (and in such case, except to the extent
     includable pursuant to clause (i) above), the net income (or loss) of any
     Person accrued prior to the date it becomes a Restricted Subsidiary or is
     merged into or consolidated with the Guarantor or any of its Restricted
     Subsidiaries or all or substantially all of the property and assets of such
     Person are acquired by the Guarantor or any of its Restricted Subsidiaries;
     (iii) the net income of any Restricted Subsidiary to the extent that the
     declaration or payment of dividends or similar distributions by such
     Restricted Subsidiary of such net income is not at the time permitted by
     the operation of the terms of its charter or any agreement, instrument,
     judgment, decree, order, statute, rule or governmental regulation
     applicable to such Restricted Subsidiary; (iv) any gains or losses (on an
     after-tax basis) attributable to Asset Sales; (v) except for purposes of
     calculating the amount of Restricted Payments that may be made pursuant to
     clause (C) of the first paragraph of Section 4.04, any amount paid or
     accrued as dividends on preferred stock of the Guarantor or any Restricted
     Subsidiary owned by Persons other than the Guarantor and any of its
     Restricted Subsidiaries; and (vi) all extraordinary gains and extraordinary
     losses. 

              "Adjusted Consolidated Net Tangible Assets" means the total
     amount of assets of the Guarantor and its Restricted Subsidiaries (less
     applicable depreciation, amortization and other valuation reserves), except
     to the extent resulting from write-ups of capital assets (excluding write-
     ups in connection with accounting for acquisitions in conformity with
     GAAP), after deducting therefrom (i) all current liabilities of the
     Guarantor and its Restricted Subsidiaries (excluding intercompany items)
     and (ii) all goodwill, trade names, trademarks, patents, unamortized debt
     discount and expense and other like intangibles, all as set forth on the
     most recently available quarterly or annual consolidated balance sheet of
     the Guarantor and its Restricted Subsidiaries, prepared in conformity with
     GAAP. 

              "Affiliate" means, as applied to any Person, any other Person
     directly or indirectly controlling, controlled by, or under direct or
     indirect common control with, such Person.  For purposes of this
     definition, "control" (including, with correlative meanings, the terms
     "controlling," "controlled by" and "under common control with"), as applied
     to any Person, means the possession, directly or indirectly, of the power
     to direct or cause the direction of the management and policies of such
     Person, whether through the ownership of voting securities, by contract or
     otherwise. 

              "Agent" means any Registrar, Paying Agent, authenticating agent
     or co-Registrar.

              "Agent Members" has the meaning provided in Section 2.07(a).

              "Asset Acquisition" means (i) an investment by the Guarantor or
     any of its Restricted Subsidiaries in any other Person pursuant to which
     such Person shall become a Restricted Subsidiary of the Guarantor or shall
     be merged into or consolidated with the Guarantor or any of its Restricted
     Subsidiaries; provided that such Person's primary business is related,
     ancillary or complementary to the businesses of the Guarantor and its
     Restricted Subsidiaries on the date of such investment or (ii) an
     acquisition by the Guarantor or any of its Restricted Subsidiaries of the
     property and assets of any Person other than the Guarantor or any of its
     Restricted Subsidiaries that constitute substantially all of a division or
     line of business of such Person; provided that the property and assets
     acquired are related, ancillary or complementary to the businesses of the
     Guarantor and its Restricted Subsidiaries on the date of such acquisition. 

              "Asset Sale" means any sale, transfer or other disposition
     (including by way of merger, consolidation or sale-leaseback transactions)
     in one transaction or a series of related transactions by the Guarantor or
     any of its Restricted Subsidiaries to any Person other than the Guarantor
     or any of its Restricted Subsidiaries of (i) all or any of the Capital
     Stock of any Restricted Subsidiary, (ii) all or substantially all of the
     property and assets of an operating unit or business of the Guarantor or
     any of its Restricted Subsidiaries or (iii) any other property and assets
     of the Guarantor or any of its Restricted Subsidiaries outside the ordinary
     course of business of the Guarantor or such Restricted Subsidiary and, in
     each case, that is not governed by the provisions of Article Five; provided
     that the meaning of "Asset Sale" shall not include (A) sales or other
     dispositions of inventory, receivables and other current assets, and (B)
     dispositions of assets of the Guarantor or any of its Restricted
     Subsidiaries, in substantially simultaneous exchanges for consideration
     consisting of any combination of cash, Temporary Cash Investments and
     assets that are used or useful in the telecommunications business of the
     Guarantor or its Restricted Subsidiaries, if such consideration has an
     aggregate fair market value substantially equal to the fair market value of
     the assets so disposed of; provided, however, that fair market value shall
     be determined in good faith by the Board of Directors of the Company, whose
     determination shall be conclusive and evidenced by a Board Resolution
     delivered to the Trustee; and provided further that any cash or Temporary
     Cash Investments received by the Guarantor or any of its Restricted
     Subsidiaries pursuant to any transaction described in clause (B) above
     shall be applied in accordance with clause (A) or (B) of the first
     paragraph of Section 4.11. 

              "Average Life" means, at any date of determination with respect
     to any debt security, the quotient obtained by dividing (i) the sum of the
     products of (a) the number of years from such date of determination to the
     dates of each successive scheduled principal payment of such debt security
     and (b) the amount of such principal payment by (ii) the sum of all such
     principal payments. 

              "Board of Directors" means the Board of Directors of the Company
     or the Guarantor as required by the context or any committee of such Board
     of Directors duly authorized to act under this Indenture.

              "Board Resolution" means a copy of a resolution, certified by the
     Secretary or Assistant Secretary of the Company or the Guarantor as
     required by the context to have been duly adopted by the Board of Directors
     and to be in full force and effect on the date of such certification, and
     delivered to the Trustee.

              "Business Day" means any day except a Saturday, Sunday or other
     day on which commercial banks in The City of New York, or in the city of
     the Corporate Trust Office of the Trustee, are authorized by law to close.

              "Capital Stock" means, with respect to any Person, any and all
     shares, interests, participations or other equivalents (however designated,
     whether voting or non-voting) in equity of such Person, whether now
     outstanding or issued after the date of this Indenture, including, without
     limitation, all Common Stock and preferred stock. 

              "Capitalized Lease" means, as applied to any Person, any lease of
     any property (whether real, personal or mixed) of which the discounted
     present value of the rental obligations of such Person as lessee, in
     conformity with GAAP, is required to be capitalized on the balance sheet of
     such Person; and "Capitalized Lease Obligations" means the discounted
     present value of the rental obligations under such lease. 

              "Change of Control" means such time as (i) a "person" or "group"
     (within the meaning of Sections 13(d) and 14(d)(2) of the Exchange Act)
     becomes the ultimate "beneficial owner" (as defined in Rule 13d-3 under the
     Exchange Act) of Voting Stock having more than 40% of the voting power of
     the total Voting Stock of the Guarantor on a fully diluted basis; (ii)
     individuals who on the Closing Date constitute the Board of Directors of
     the Guarantor (together with any new directors whose election by the Board
     of Directors or whose nomination for election by the Guarantor's
     stockholders was approved by a vote of at least a majority of the members
     of the Board of Directors then in office who either were members of the
     Board of Directors on the Closing Date or whose election or nomination for
     election was previously so approved) cease for any reason to constitute a
     majority of the members of the Board of Directors then in office; or (iii)
     all of the Common Stock of the Company is not beneficially owned by the
     Guarantor.

              "Change of Control Offer" has the meaning provided in Section
     4.04(ix). 

              "ChoiceCom" means CSW/ICG ChoiceCom, L.P., a Delaware limited
     partnership. 

              "Closing Date" means the date on which the Securities are
     originally issued under this Indenture. 

              "Commission" means the Securities and Exchange Commission, as
     from time to time constituted, created under the Exchange Act or, if at any
     time after the execution of this instrument such Commission is not existing
     and performing the duties now assigned to it under the TIA, then the body
     performing such duties at such time.

              "Common Stock" means, with respect to any Person, any and all
     shares, interests, participations or other equivalents (however designated,
     whether voting or non-voting) of such Person's common equity interests,
     whether now outstanding or issued after the date of this Indenture,
     including, without limitation, all series and classes of such common equity
     interests, but excluding all equity interests entitled to a preference with
     respect to dividends or distributions or upon liquidation.

              "Company" means the party named as such in the first paragraph of
     this Indenture until a successor replaces it pursuant to Article Five of
     this Indenture and thereafter means the successor.

              "Company Order" means a written request or order signed in the
     name of the Company (i) by its Chairman, a Vice Chairman, its President or
     a Vice President and (ii) by its Treasurer, an Assistant Treasurer, its
     Secretary or an Assistant Secretary and delivered to the Trustee; provided,
     however, that such written request or order may be signed by any two of the
     officers or directors listed in clause (i) above in lieu of being signed by
     one of such officers or directors listed in such clause (i) and one of the
     officers listed in clause (ii) above.

              "Consolidated EBITDA" means, for any period, the sum of the
     amounts for such period of (i) Adjusted Consolidated Net Income, (ii)
     Consolidated Interest Expense, (iii) income taxes, to the extent such
     amount was deducted in calculating Adjusted Consolidated Net Income (other
     than income taxes (either positive or negative) attributable to
     extraordinary and non-recurring gains or losses or sales of assets), (iv)
     depreciation expense, to the extent such amount was deducted in calculating
     Adjusted Consolidated Net Income, (v) amortization expense, to the extent
     such amount was deducted in calculating Adjusted Consolidated Net Income,
     and (vi) all other non-cash items reducing Adjusted Consolidated Net Income
     (other than items that will require cash payments and for which an accrual
     or reserve is, or is required by GAAP to be, made), less all non-cash items
     increasing Adjusted Consolidated Net Income, all as determined on a
     consolidated basis for the Guarantor and its Restricted Subsidiaries in
     conformity with GAAP; provided that, if any Restricted Subsidiary is not a
     Wholly Owned Restricted Subsidiary, Consolidated EBITDA shall be reduced
     (to the extent not otherwise reduced in accordance with GAAP) by an amount
     equal to (A) the amount of the Adjusted Consolidated Net Income
     attributable to such Restricted Subsidiary multiplied by (B) the quotient
     of (1) the number of shares of outstanding Common Stock of such Restricted
     Subsidiary not owned on the last day of such period by the Guarantor or any
     of its Restricted Subsidiaries divided by (2) the total number of shares of
     outstanding Common Stock of such Restricted Subsidiary on the last day of
     such period. 

              "Consolidated Indebtedness" means the aggregate amount of
     Indebtedness of the Guarantor, the Company and their Restricted
     Subsidiaries on a consolidated basis.

              "Consolidated Interest Expense" means, for any period, the
     aggregate amount of interest in respect of Indebtedness (including
     amortization of original issue discount on any Indebtedness and the
     interest portion of any deferred payment obligation, calculated in
     accordance with the effective interest method of accounting; all
     commissions, discounts and other fees and charges owed with respect to
     letters of credit and bankers' acceptance financing; the net costs
     associated with Interest Rate Agreements; and Indebtedness that is
     Guaranteed or secured by the Guarantor or any of its Restricted
     Subsidiaries) and all but the principal component of rentals in respect of
     Capitalized Lease Obligations paid, accrued or scheduled to be paid or to
     be accrued by the Guarantor and its Restricted Subsidiaries during such
     period; excluding, however, without duplication, (i) any amount of such
     interest of any Restricted Subsidiary if the net income of such Restricted
     Subsidiary is excluded in the calculation of Adjusted Consolidated Net
     Income pursuant to clause (iii) of the definition thereof (but only in the
     same proportion as the net income of such Restricted Subsidiary is excluded
     from the calculation of Adjusted Consolidated Net Income pursuant to clause
     (iii) of the definition thereof) and (ii) any premiums, fees and expenses
     (and any amortization thereof) payable in connection with the offering of
     the 13 1/2% Notes and the warrants issued therewith, the 12 1/2% Notes, the
     14 1/4% Preferred Stock, the Securities and/or the Exchangeable Preferred
     Stock, all as determined on a consolidated basis (without taking into
     account Unrestricted Subsidiaries) in conformity with GAAP. 

              "Consolidated Net Worth" means, at any date of determination,
     stockholders' equity as set forth on the most recently available quarterly
     or annual consolidated balance sheet of the Guarantor and its Restricted
     Subsidiaries (which shall be as of a date not more than 90 days prior to
     the date of such computation, and which shall not take into account
     Unrestricted Subsidiaries), less any amounts attributable to Redeemable
     Stock or any equity security convertible into or exchangeable for
     Indebtedness, the cost of treasury stock and the principal amount of any
     promissory notes receivable from the sale of the Capital Stock of the
     Guarantor or any of its Restricted Subsidiaries, each item to be determined
     in conformity with GAAP (excluding the effects of foreign currency exchange
     adjustments under Financial Accounting Standards Board Statement of
     Financial Accounting Standards No. 52). 

              "Corporate Trust Office" means the office of the Trustee at which
     the corporate trust business of the Trustee shall, at any particular time,
     be principally administered, which office is, at the date of this
     Indenture, located at 1740 Broadway, Denver, Colorado 80274-8693,
     Attention:  Corporate Trust and Escrow Services.

              "Currency Agreement" means any foreign exchange contract,
     currency swap agreement or other similar agreement or arrangement designed
     to protect the Guarantor or any of its Restricted Subsidiaries against
     fluctuations in currency values to or under which the Guarantor or any of
     its Restricted Subsidiaries is a party or a beneficiary on the date of this
     Indenture or becomes a party or a beneficiary thereafter.

              "Default" means any event that is, or after notice or passage of
     time or both would be, an Event of Default.

              "Depositary" shall mean The Depository Trust Company, its
     nominees, and their respective successors.

              "Event of Default" has the meaning provided in Section 6.01.

              "Excess Proceeds" has the meaning provided in Section 4.11.

              "Exchange Act" means the Securities Exchange Act of 1934, as
     amended.

              "Exchange Securities" means any securities of the Company
     containing terms identical to the Securities (except that such Exchange
     Securities (i) shall be registered under the Securities Act, (ii) will not
     provide for an increase in the rate of interest (other than with respect to
     overdue amounts) and (iii) will not contain terms with respect to transfer
     restrictions) that are issued and exchanged for the Securities pursuant to
     the Registration Rights Agreement and this Indenture.

              "Exchangeable Preferred Stock" means the Preferred Stock of the
     Company issued on the Closing Date and any shares of Preferred Stock issued
     as payment in kind dividends thereon.

              "FOTI" means Fiber Optic Technologies Inc., a Colorado
     corporation. 

              "14 1/4% Preferred Stock" means the 14 1/4% Exchangeable
     Preferred Stock mandatorily redeemable May 1, 2007 of the Company, and any
     shares of preferred stock issued as payment in kind dividends thereon. 

              "GAAP" means generally accepted accounting principles in the
     United States of America as in effect as of August 8, 1995, including,
     without limitation, those set forth in the opinions and pronouncements of
     the Accounting Principles Board of the American Institute of Certified
     Public Accountants and statements and pronouncements of the Financial
     Accounting Standards Board or in such other statements by such other entity
     as approved by a significant segment of the accounting profession. All
     ratios and computations contained in this Indenture shall be computed in
     conformity with GAAP applied on a consistent basis, except that
     calculations made for purposes of determining compliance with the terms of
     the covenants and with other provisions of this Indenture shall be made
     without giving effect to (i) the amortization of any expenses incurred in
     connection with the offering of the 13 1/2% Notes and the warrants issued
     therewith, the 12 1/2% Notes, the 14 1/4% Preferred Stock, the Securities
     and/or the Exchangeable Preferred Stock and (ii) except as otherwise
     provided, the amortization of any amounts required or permitted by
     Accounting Principles Board Opinion Nos. 16 and 17. 

              "Global Securities" has the meaning provided in Section 2.01.

              "Guarantee" means any obligation, contingent or otherwise, of any
     Person directly or indirectly guaranteeing any Indebtedness or other
     obligation of any other Person and, without limiting the generality of the
     foregoing, any obligation, direct or indirect, contingent or otherwise, of
     such Person (i) to purchase or pay (or advance or supply funds for the
     purchase or payment of) such Indebtedness or other obligation of such other
     Person (whether arising by virtue of partnership arrangements, or by
     agreements to keep-well, to purchase assets, goods, securities or services,
     to take-or-pay, or to maintain financial statement conditions or otherwise)
     or (ii) entered into for purposes of assuring in any other manner the
     obligee of such Indebtedness or other obligation of the payment thereof or
     to protect such obligee against loss in respect thereof (in whole or in
     part); provided that the term "Guarantee" shall not include endorsements
     for collection or deposit in the ordinary course of business. The term
     "Guarantee" used as a verb has a corresponding meaning. 

              "Guaranteed Indebtedness" has the meaning provided in Section
     4.07.

              "Guarantor" means the party named as such in the first paragraph
     of this Indenture until a successor replaces it pursuant to Article Five of
     this Indenture and thereafter means the successor.

              "Holder" or "Securityholder" means the registered holder of any
     Security. 

              "Holdings (Canada)" means ICG Holdings (Canada), Inc. and its
     successors and assigns. 

              "Incur" means, with respect to any Indebtedness, to incur,
     create, issue, assume, Guarantee or otherwise become liable for or with
     respect to, or become responsible for, the payment of, contingently or
     otherwise, such Indebtedness, including an Incurrence of Indebtedness by
     reason of the acquisition of more than 50% of the Capital Stock of any
     Person; provided that neither the accrual of interest nor the accretion of
     original issue discount shall be considered an Incurrence of Indebtedness.
     The term "Incurrence" has a corresponding meaning. 

              "Indebtedness" means, with respect to any Person at any date of
     determination (without duplication), (i) all indebtedness of such Person
     for borrowed money, (ii) all obligations of such Person evidenced by bonds,
     debentures, notes or other similar instruments, (iii) all obligations of
     such Person in respect of letters of credit or other similar instruments
     (including reimbursement obligations with respect thereto), (iv) all
     obligations of such Person to pay the deferred and unpaid purchase price of
     property or services, which purchase price is due more than six months
     after the date of placing such property in service or taking delivery and
     title thereto or the completion of such services, except Trade Payables,
     (v) all obligations of such Person as lessee under Capitalized Leases, (vi)
     all Indebtedness of other Persons secured by a Lien on any asset of such
     Person, whether or not such Indebtedness is assumed by such Person;
     provided that the amount of such Indebtedness shall be the lesser of (A)
     the fair market value of such asset at such date of determination and (B)
     the amount of such Indebtedness, (vii) all Indebtedness of other Persons
     Guaranteed by such Person to the extent such Indebtedness is Guaranteed by
     such Person and (viii) to the extent not otherwise included in this
     definition, obligations under Currency Agreements and Interest Rate
     Agreements. The amount of Indebtedness of any Person at any date shall be
     the outstanding balance at such date of all unconditional obligations as
     described above and, with respect to contingent obligations, the maximum
     liability upon the occurrence of the contingency giving rise to the
     obligation, provided (i) that the amount outstanding at any time of any
     Indebtedness issued with original issue discount is the original issue
     price of such Indebtedness and (ii) that Indebtedness shall not include (A)
     any amount of money borrowed, at the time of the Incurrence of the related
     Indebtedness, for the purpose of pre-funding any interest payable on such
     related Indebtedness or (B) any liability for federal, state, local or
     other taxes. 

              "Indebtedness to EBITDA Ratio" means, as at any date of
     determination, the ratio of (i) the Consolidated Indebtedness as at the
     Transaction Date to (ii) the Consolidated EBITDA of the Guarantor for the
     then most recent four full fiscal quarters for which reports have been
     filed pursuant to Section 4.18 (such four full fiscal quarter period being
     referred to herein as the "Four Quarter Period"); provided that (x) pro
                                -------------------
     forma effect shall be given to any Indebtedness Incurred from the beginning
     of the Four Quarter Period through the Transaction Date (including any
     Indebtedness Incurred on the Transaction Date), to the extent outstanding
     on the Transaction Date, (y) if during the period commencing on the first
     day of such Four Quarter Period through the Transaction Date (the
     "Reference Period"), the Guarantor, the Company or any of the Restricted 
      ----------------
     Subsidiaries shall have engaged in any Asset Sale, Consolidated EBITDA for
     such period shall be reduced by an amount equal to the EBITDA (if
     positive), or increased by an amount equal to the EBITDA (if negative),
     directly attributable to the assets which are the subject of such Asset
     Sale and any related retirement of Indebtedness as if such Asset Sale and
     related retirement of Indebtedness had occurred on the first day of such
     Reference Period or (z) if during such Reference Period the Guarantor, the
     Company or any of the Restricted Subsidiaries shall have made any Asset
     Acquisition, Consolidated EBITDA of the Guarantor shall be calculated on a
     pro forma basis as if such Asset Acquisition and any related financing had
     occurred on the first day of such Reference Period. 

              "Indenture" means this Indenture as originally executed or as it
     may be amended or supplemented from time to time by one or more indentures
     supplemental to this Indenture entered into pursuant to the applicable
     provisions of this Indenture.

              "Institutional Accredited Investor" shall mean an institution
     that is an "accredited investor" as that term is defined in Rule 501(a)(1),
     (2), (3) or (7) of Regulation D under the Securities Act.

              "Interest Payment Date" means each semiannual interest payment
     date on March 15 and September 15 of each year, commencing September 15,
     2002.

              "Interest Rate Agreement" means any interest rate protection
     agreement, interest rate future agreement, interest rate option agreement,
     interest rate swap agreement, interest rate cap agreement, interest rate
     collar agreement, interest rate hedge agreement or other similar agreement
     or arrangement designed to protect the Guarantor or any of its Restricted
     Subsidiaries against fluctuations in interest rates in respect of
     Indebtedness to or under which the Guarantor or any of its Restricted
     Subsidiaries is a party or a beneficiary on the date of this Indenture or
     becomes a party or a beneficiary hereafter; provided that the notional
     principal amount thereof does not exceed the principal amount of the
     Indebtedness of the Guarantor and its Restricted Subsidiaries that bears
     interest at floating rates.

              "Investment" in any Person means any direct or indirect advance,
     loan or other extension of credit (including, without limitation, by way of
     Guarantee or similar arrangement; but excluding advances to customers in
     the ordinary course of business that are, in conformity with GAAP, recorded
     as accounts receivable on the balance sheet of the Guarantor or its
     Restricted Subsidiaries) or capital contribution to (by means of any
     transfer of cash or other property to others or any payment for property or
     services for the account or use of others), or any purchase or acquisition
     of Capital Stock, bonds, notes, debentures or other similar instruments
     issued by, such Person and shall include the designation of a Restricted
     Subsidiary as an Unrestricted Subsidiary.  For purposes of the definition
     of "Unrestricted Subsidiary" and Section 4.04, (i) "Investment" shall
     include the fair market value of the assets (net of liabilities) of any
     Restricted Subsidiary of the Guarantor at the time that such Restricted
     Subsidiary of the Guarantor is designated an Unrestricted Subsidiary and
     shall exclude the fair market value of the assets (net of liabilities) of
     any Unrestricted Subsidiary at the time that such Unrestricted Subsidiary
     is designated a Restricted Subsidiary of the Guarantor and (ii) any
     property transferred to or from an Unrestricted Subsidiary shall be valued
     at its fair market value at the time of such transfer, in each case as
     determined by the Board of Directors in good faith. 

              "Lien" means any mortgage, pledge, security interest,
     encumbrance, lien or charge of any kind (including, without limitation, any
     conditional sale or other title retention agreement or lease in the nature
     thereof, any sale with recourse against the seller or any Affiliate of the
     seller, or any agreement to give any security interest). 

              "MTN" means Maritime Telecommunications Network, Inc., a Colorado
     corporation, and its successors. 

              "Net Cash Proceeds" means (a) with respect to any Asset Sale, the
     proceeds of such Asset Sale in the form of cash or cash equivalents,
     including payments in respect of deferred payment obligations (to the
     extent corresponding to the principal, but not interest, component thereof)
     when received in the form of cash or cash equivalents (except to the extent
     such obligations are financed or sold with recourse to the Guarantor or any
     Restricted Subsidiary of the Guarantor) and proceeds from the conversion of
     other property received when converted to cash or cash equivalents, net of
     (i) brokerage commissions and other fees and expenses (including fees and
     expenses of counsel and investment bankers) related to such Asset Sale,
     (ii) provisions for all taxes (whether or not such taxes will actually be
     paid or are payable) as a result of such Asset Sale without regard to the
     consolidated results of operations of the Guarantor and its Restricted
     Subsidiaries, taken as a whole, (iii) payments made to repay Indebtedness
     or any other obligation outstanding at the time of such Asset Sale that
     either (A) is secured by a Lien on the property or assets sold or (B) is
     required to be paid as a result of such sale and (iv) appropriate amounts
     to be provided by the Guarantor or any Restricted Subsidiary of the
     Guarantor as a reserve against any liabilities associated with such Asset
     Sale, including, without limitation, pension and other post-employment
     benefit liabilities, liabilities related to environmental matters and
     liabilities under any indemnification obligations associated with such
     Asset Sale, all as determined in conformity with GAAP and (b) with respect
     to any issuance or sale of Capital Stock, the proceeds of such issuance or
     sale in the form of cash or cash equivalents, including payments in respect
     of deferred payment obligations (to the extent corresponding to the
     principal, but not interest, component thereof) when received in the form
     of cash or cash equivalents (except to the extent such obligations are
     financed or sold with recourse to the Guarantor or any Restricted
     Subsidiary of the Guarantor) and proceeds from the conversion of other
     property received when converted to cash or cash equivalents, net of
     attorney's fees, accountants' fees, underwriters' or placement agents'
     fees, discounts or commissions and brokerage, consultant and other fees
     incurred in connection with such issuance or sale and net of taxes paid or
     payable as a result thereof. 

              "Non-U.S. Person" means a person who is not a U.S. person, as
     defined in Regulation S.

              "Offer to Purchase" means an offer to purchase Securities by the
     Company from the Holders commenced by mailing a notice to the Trustee and
     each Holder stating: (i) the covenant pursuant to which the offer is being
     made and that all Securities validly tendered will be accepted for payment
     on a pro rata basis; (ii) the purchase price and the Payment Date; (iii)
     that any Security not tendered will continue to accrue interest pursuant to
     its terms; (iv) that, unless the Company defaults in the payment of the
     purchase price, any Security accepted for payment pursuant to the Offer to
     Purchase shall cease to accrue interest on and after the Payment Date; (v)
     that Holders electing to have a Security purchased pursuant to the Offer to
     Purchase will be required to surrender the Security, together with the form
     entitled "Option of the Holder to Elect Purchase" on the reverse side of
     the Security completed, to the Paying Agent at the address specified in the
     notice prior to the close of business on the Business Day immediately
     preceding the Payment Date; (vi) that Holders will be entitled to withdraw
     their election if the Paying Agent receives, not later than the close of
     business on the third Business Day immediately preceding the Payment Date,
     a telegram, facsimile transmission or letter setting forth the name of such
     Holder, the principal amount of Securities delivered for purchase and a
     statement that such Holder is withdrawing his election to have such
     Securities purchased; and (vii) that Holders whose Securities are being
     purchased only in part will be issued new Securities equal in principal
     amount to the unpurchased portion of the Securities surrendered; provided
     that each Security purchased and each new Security issued shall be in a
     principal amount of $1,000 or integral multiples thereof. On the Payment
     Date, the Company shall (i) accept for payment on a pro rata basis
     Securities or portions thereof tendered pursuant to an Offer to Purchase;
     (ii) deposit with the Paying Agent money sufficient to pay the purchase
     price of all Securities or portions thereof so accepted; and (iii) deliver,
     or cause to be delivered, to the Trustee all Securities or portions thereof
     so accepted together with an Officers' Certificate specifying the
     Securities or portions thereof accepted for payment by the Company. The
     Paying Agent shall promptly mail to the Holders of Securities so accepted
     payment in an amount equal to the purchase price, and the Trustee shall
     promptly authenticate and mail to such Holders a new Security equal in
     principal amount to any unpurchased portion of the Security surrendered;
     provided that each Security purchased and each new Security issued shall be
     in a principal amount of $1,000 or integral multiples thereof.  The Company
     will publicly announce the results of an Offer to Purchase as soon as
     practicable after the Payment Date. The Trustee shall act as the Paying
     Agent for an Offer to Purchase.  The Company will comply with Rule 14e-1
     under the Exchange Act and any other securities laws and regulations
     thereunder to the extent such laws and regulations are applicable, in the
     event that the Company is required to repurchase Securities pursuant to an
     Offer to Purchase. 

              "Officer" means, with respect to the Company or the Guarantor,
     (i) the Chairman of the Board, the President, any Vice President or the
     Chief Financial Officer and (ii) the Treasurer or any Assistant Treasurer,
     or the Secretary or any Assistant Secretary.

              "Officers' Certificate" means a certificate signed by one Officer
     listed in clause (i) of the definition thereof and one Officer listed in
     clause (ii) of the definition thereof; provided, however, that any such
     certificate may be signed by any two of the Officers listed in clause (i)
     of the definition thereof in lieu of being signed by one Officer listed in
     clause (i) of the definition thereof and one Officer listed in clause (ii)
     of the definition thereof.  Each Officers' Certificate (other than
     certificates provided pursuant to TIA Section 314(a)(4)) shall include the
     statements provided for in TIA Section 314(e).

              "Offshore Global Security" has the meaning provided in Section
     2.01.

              "Offshore Physical Securities" has the meaning provided in
     Section 2.01.

              "Ohio LINX" means ICG Ohio LINX, Inc., an Ohio corporation.

              "Opinion of Counsel" means a written opinion signed by legal
     counsel who may be an employee of or counsel to the Company.  Each such
     Opinion of Counsel shall include the statements provided for in TIA Section
     314(e).

              "Outstanding Securities" has the meaning provided in
     Section 2.10.

              "Paying Agent" has the meaning provided in Section 2.04, except
     that, for the purposes of Article Eight, the Paying Agent shall not be the
     Company or a Subsidiary of the Company or an Affiliate of any of them.  The
     term "Paying Agent" includes any additional Paying Agent.

              "Payment Date" means the date of purchase, which shall be a
     Business Day no earlier than 30 days nor later than 60 days from the date a
     notice is mailed pursuant to an Offer to Purchase.

              "Permitted Investment" means (i) an Investment in a Restricted
     Subsidiary or a Person which will, upon the making of such Investment,
     become a Restricted Subsidiary or be merged or consolidated with or into or
     transfer or convey all or substantially all its assets to, the Guarantor or
     a Restricted Subsidiary; provided that such person's primary business is
     related, ancillary or complementary to the businesses of the Guarantor and
     its Restricted Subsidiaries on the date of such Investment; (ii) a
     Temporary Cash Investment; (iii) payroll, travel and similar advances to
     cover matters that are expected at the time of such advances ultimately to
     be treated as expenses in accordance with GAAP; (iv) loans or advances to
     employees made in the ordinary course of business in accordance with past
     practice of the Guarantor or its Restricted Subsidiaries and that do not in
     the aggregate exceed $2 million at any time outstanding; (v) stock,
     obligations or securities received in satisfaction of judgments; and (vi)
     Investments in an amount not to exceed, at any one time outstanding, all of
     the net cash proceeds received by the Guarantor from the sale of its Common
     Stock (to a Person other than one of its Subsidiaries) after the Closing
     Date. 

              "Permitted Liens" means (i) Liens for taxes, assessments,
     governmental charges or claims that are being contested in good faith by
     appropriate legal proceedings promptly instituted and diligently conducted
     and for which a reserve or other appropriate provision, if any, as shall be
     required in conformity with GAAP shall have been made; (ii) statutory Liens
     of landlords and carriers, warehousemen, mechanics, suppliers, materialmen,
     repairmen or other similar Liens arising in the ordinary course of business
     and with respect to amounts not yet delinquent or being contested in good
     faith by appropriate legal proceedings promptly instituted and diligently
     conducted and for which a reserve or other appropriate provision, if any,
     as shall be required in conformity with GAAP shall have been made; (iii)
     Liens incurred or deposits made in the ordinary course of business in
     connection with workers' compensation, unemployment insurance and other
     types of social security; (iv) Liens incurred or deposits made to secure
     the performance of tenders, bids, leases, statutory or regulatory
     obligations, bankers' acceptances, surety and appeal bonds, government
     contracts, performance and return-of-money bonds and other obligations of a
     similar nature incurred in the ordinary course of business (exclusive of
     obligations for the payment of borrowed money); (v) easements, rights of
     way, municipal and zoning ordinances and similar charges, encumbrances,
     title defects or other irregularities that do not materially interfere with
     the ordinary course of business of the Guarantor or any of its Restricted
     Subsidiaries; (vi) Liens (including extensions and renewals thereof) upon
     real or personal property acquired after the Closing Date; provided that
     (a) such Lien is created solely for the purpose of securing Indebtedness
     Incurred, in accordance with Section 4.03, (1) to finance the cost
     (including the cost of improvement or construction) of the item of property
     or assets subject thereto and such Lien is created prior to, at the time of
     or within six months after the later of the acquisition, the completion of
     construction or the commencement of full operation of such property or (2)
     to refinance any Indebtedness previously so secured, (b) the principal
     amount of the Indebtedness secured by such Lien does not exceed 100% of
     such cost and (c) any such Lien shall not extend to or cover any property
     or assets other than such item of property or assets and any improvements
     on such item; (vii) leases or subleases granted to others that do not
     materially interfere with the ordinary course of business of the Guarantor
     and its Restricted Subsidiaries, taken as a whole; (viii) Liens encumbering
     property or assets under construction arising from progress or partial
     payments by a customer of the Guarantor or its Restricted Subsidiaries
     relating to such property or assets; (ix) any interest or title of a lessor
     in the property subject to any Capitalized Lease or operating lease; (x)
     Liens arising from filing Uniform Commercial Code financing statements
     regarding leases; (xi) Liens on property of, or on shares of stock or
     Indebtedness of, any corporation existing at the time such corporation
     becomes, or becomes a part of, any Restricted Subsidiary; provided that
     such Liens do not extend to or cover any property or assets of the
     Guarantor or any Restricted Subsidiary other than the property or assets
     acquired; (xii) Liens in favor of the Guarantor or any Restricted
     Subsidiary; (xiii) Liens arising from the rendering of a final judgment or
     order against the Guarantor or any Restricted Subsidiary of the Guarantor
     that does not give rise to an Event of Default; (xiv) Liens securing
     reimbursement obligations with respect to letters of credit that encumber
     documents and other property relating to such letters of credit and the
     products and proceeds thereof; (xv) Liens in favor of customs and revenue
     authorities arising as a matter of law to secure payment of customs duties
     in connection with the importation of goods; (xvi) Liens encumbering
     customary initial deposits and margin deposits, and other Liens that are
     either within the general parameters customary in the industry and incurred
     in the ordinary course of business, in each case, securing Indebtedness
     under Interest Rate Agreements and Currency Agreements and forward
     contracts, options, future contracts, futures options or similar agreements
     or arrangements designed to protect the Guarantor or any of its Restricted
     Subsidiaries from fluctuations in the price of commodities; (xvii) Liens
     arising out of conditional sale, title retention, consignment or similar
     arrangements for the sale of goods entered into by the Guarantor or any of
     its Restricted Subsidiaries in the ordinary course of business in
     accordance with the past practices of the Guarantor and its Restricted
     Subsidiaries prior to the Closing Date; and (xviii) Liens on or sales of
     receivables. 

              "Person" means an individual, a corporation, a partnership, a
     limited liability company, an association, a trust or any other entity or
     organization, including a government or political subdivision or an agency
     or instrumentality thereof.

              "Physical Securities" has the meaning provided in Section 2.01.

              "Preferred stock" or "preferred stock" means, with respect to any
     Person, any and all shares, interests, participations or other equivalents
     (however designated, whether voting or non-voting) of such Person's
     preferred or preference stock, whether now outstanding or issued after the
     date of this Indenture, including, without limitation, all series and
     classes of such preferred or preference stock. 

              "principal" of a debt security, including the Securities, means
     the principal amount due on the Stated Maturity as shown on such debt
     security.

              "Private Placement Legend" means the legend initially set forth
     on the Securities in the form set forth in Section 2.02.

              "Public Equity Offering" means a bona fide underwritten primary
     public offering of Common Stock of the Guarantor or the Company pursuant to
     an effective registration statement under the Securities Act. 

              "QIB" means a "qualified institutional buyer" as defined in Rule
     144A.

              "Redeemable Stock" means any class or series of Capital Stock of
     any Person that by its terms or otherwise is (i) required to be redeemed
     prior to the Stated Maturity of the Securities, (ii) redeemable at the
     option of the holder of such class or series of Capital Stock at any time
     prior to the Stated Maturity of the Securities or (iii) convertible into or
     exchangeable for Capital Stock referred to in clause (i) or (ii) above or
     Indebtedness having a scheduled maturity prior to the Stated Maturity of
     the Securities; provided that any Capital Stock that would not constitute
     Redeemable Stock but for provisions thereof giving holders thereof the
     right to require such Person to repurchase or redeem such Capital Stock
     upon the occurrence of an "asset sale" or "change of control" occurring
     prior to the Stated Maturity of the Securities shall not constitute
     Redeemable Stock if the "asset sale" or "change of control" provisions
     applicable to such Capital Stock are no more favorable to the holders of
     such Capital Stock than the provisions contained in Sections 4.11 and 4.12
     and such Capital Stock specifically provides that such Person will not
     repurchase or redeem any such stock pursuant to such provision prior to the
     Guarantor's repurchase of such Securities as are required to be repurchased
     pursuant to the provisions of Sections 4.11 and 4.12.

              "Redemption Date", when used with respect to any Security to be
     redeemed, means the date fixed for such redemption by or pursuant to this
     Indenture.

              "Redemption Price", when used with respect to any Security to be
     redeemed, means the price at which such Security is to be redeemed pursuant
     to this Indenture.

              "Registrar" has the meaning provided in Section 2.04.

              "Registration Rights Agreement" means the Registration Rights
     Agreement, dated March 11, 1997, among the Company, the Guarantor and
     Morgan Stanley & Co. Incorporated relating to the Securities.

              "Registration Statement" means the Registration Statement as
     defined and described in the Registration Rights Agreement.

              "Regular Record Date" for the interest payable on any Interest
     Payment Date means the March 1 or September 1 (whether or not a Business
     Day), as the case may be, next preceding such Interest Payment Date.

              "Regulation S" means Regulation S under the Securities Act.

              "Responsible Officer", when used with respect to the Trustee,
     means the chairman or any vice chairman of the board of directors, the
     chairman or any vice chairman of the executive committee of the board of
     directors, the chairman of the trust committee, the president, any vice
     president, any assistant vice president, the secretary, any assistant
     secretary, the treasurer, any assistant treasurer, the cashier, any
     assistant cashier, any trust officer or assistant trust officer, the
     controller or any assistant controller or any other officer of the Trustee
     customarily performing functions similar to those performed by any of the
     above designated officers and also means, with respect to a particular
     corporate trust matter, any other officer to whom such matter is referred
     because of his or her knowledge of and familiarity with the particular
     subject.

              "Restricted Payments" has the meaning provided in Section 4.04.

              "Restricted Subsidiary" means any Subsidiary of the Guarantor
     other than an Unrestricted Subsidiary.

              "Rule 144A" means Rule 144A under the Securities Act.

              "Securities" means any of the securities, as defined in the first
     paragraph of the recitals hereof, that are authenticated and delivered
     under this Indenture.  For all purposes of this Indenture, the term
     "Securities" shall include any Exchange Securities to be issued and
     exchanged for any Securities pursuant to the Registration Rights Agreement
     and this Indenture and, for purposes of this Indenture, all Securities and
     Exchange Securities shall vote together as one series of Securities under
     this Indenture.

              "Securities Act" means the Securities Act of 1933, as amended.

              "Security Guarantee" means the unconditional guarantee of the
     Securities by the Guarantor, as set forth in Article 10.

              "Security Register" has the meaning provided in Section 2.04.

              "Significant Subsidiary" means, at any date of determination, any
     Restricted Subsidiary of the Guarantor that, together with its
     Subsidiaries, (i) for the most recent fiscal year of the Guarantor,
     accounted for more than 10% of the consolidated revenues of the Guarantor
     and its Restricted Subsidiaries or (ii) as of the end of such fiscal year,
     was the owner of more than 10% of the consolidated assets of the Guarantor
     and its Restricted Subsidiaries, all as set forth on the most recently
     available consolidated financial statements of the Guarantor for such
     fiscal year. 

              "Specified Date" means any redemption date, any date of purchase
     for any purchase of Securities pursuant to Section 4.11 or 4.12 or any date
     on which the Securities are due and payable after an Event of Default. 

              "StarCom" means StarCom International Optics Corporation, a
     British Columbia corporation, and its subsidiaries. 

              "Stated Maturity" means, (i) with respect to any debt security,
     the date specified in such debt security as the fixed date on which the
     final installment of principal of such debt security is due and payable and
     (ii) with respect to any scheduled installment of principal of or interest
     on any debt security, the date specified in such debt security as the fixed
     date on which such installment is due and payable. 

              "Strategic Investor" means any Person engaged in the
     telecommunications business which has a net worth or equity market
     capitalization of at least $1 billion. 

              "Strategic Investor Subordinated Indebtedness" means all
     Indebtedness of the Company owed to a Strategic Investor that is
     contractually subordinate in right of payment to the Securities to at least
     the following extent: no payment of principal (or premium, if any) or
     interest on or otherwise payable in respect of such Indebtedness may be
     made (whether as a result of a default or otherwise) prior to the payment
     in full of all of the Guarantor's and the Company's obligations under the
     Securities, provided, however, that prior to the payment of such
     obligations, interest on Strategic Investor Subordinated Indebtedness may
     be payable solely in kind or in Common Stock (other than Redeemable Stock)
     of the Guarantor. 

              "Subsidiary" means, with respect to any Person, any corporation,
     association or other business entity of which more than 50% of the
     outstanding Voting Stock is owned, directly or indirectly, by such Person
     and one or more other Subsidiaries of such Person. 

              "Subsidiary Guarantee" has the meaning provided in Section 4.07.

              "Temporary Cash Investment" means any of the following: (i)
     direct obligations of the United States of America or any agency thereof or
     obligations fully and unconditionally guaranteed by the United States of
     America or any agency thereof, (ii) time deposit accounts, certificates of
     deposit and money market deposits maturing within 270 days of the date of
     acquisition thereof, bankers' acceptances with maturities not exceeding 270
     days, and overnight bank deposits, in each case issued by or with a bank or
     trust company which is organized under the laws of the United States of
     America, any state thereof or any foreign country recognized by the United
     States, and which bank or trust company has capital, surplus and undivided
     profits aggregating in excess of $100 million (or the foreign currency
     equivalent thereof) and has outstanding debt which is rated "A" (or such
     similar equivalent rating) or higher by at least one nationally recognized
     statistical rating organization (as defined in Rule 436 under the
     Securities Act) or any money-market fund sponsored by a registered broker
     dealer or mutual fund distributor, (iii) repurchase obligations with a term
     of not more than 30 days for underlying securities of the types described
     in clause (i) above entered into with a bank meeting the qualifications
     described in clause (ii) above, (iv) commercial paper, maturing not more
     than 180 days after the date of acquisition, issued by a corporation (other
     than an Affiliate of the Guarantor) organized and in existence under the
     laws of the United States of America, any state thereof or any foreign
     country recognized by the United States of America with a rating at the
     time as of which any investment therein is made of "P-1" (or higher)
     according to Moody's Investors Service, Inc. or "A-1" (or higher) according
     to Standard & Poor's Ratings Group, and (v) securities with maturities of
     six months or less from the date of acquisition issued or fully and
     unconditionally guaranteed by any state, commonwealth or territory of the
     United States of America, or by any political subdivision or taxing
     authority thereof, and rated at least "A" by Standard & Poor's Ratings
     Group or Moody's Investors Service, Inc. 

              "13 1/2% Notes" means the 13 1/2% Senior Discount Notes due 2005
     of the Company guaranteed by Holdings (Canada) and the Guarantor on a
     senior unsecured basis. 

              "TIA" or "Trust Indenture Act" means the Trust Indenture Act of
     1939, as amended (15 U.S. Code <Section><Section> 77aaa-77bbb), as in
     effect on the date this Indenture was executed, except as provided in
     Section 9.06.

              "Trade Payables" means, with respect to any Person, any accounts
     payable or any other debt or monetary obligation to trade creditors
     created, assumed or Guaranteed by such Person or any of its Subsidiaries
     arising in the ordinary course of business in connection with the
     acquisition of goods or services. 

              "Transaction Date" means, with respect to the Incurrence of any
     Indebtedness by the Guarantor or any of its Restricted Subsidiaries, the
     date such Indebtedness is to be Incurred and, with respect to any
     Restricted Payment, the date such Restricted Payment is to be made. 

              "Trustee" means the party named as such in the first paragraph of
     this Indenture until a successor replaces it in accordance with the
     provisions of Article Seven of this Indenture and thereafter means such
     successor.

              "12 1/2% Notes" means the 12 1/2% Senior Discount Notes due 2006
     of the Company guaranteed by Holdings (Canada) and the Guarantor on a
     senior unsecured basis. 

              "United States Bankruptcy Code" means the Bankruptcy Reform Act
     of 1978, as amended and as codified in Title 11 of the United States Code,
     as amended from time to time hereafter, or any successor federal bankruptcy
     law.

              "U.S. Global Security" has the meaning provided in Section 2.01.

              "U.S. Government Obligations" means securities that are (i)
     direct obligations of the United States of America for the payment of which
     its full faith and credit is pledged or (ii) obligations of a Person
     controlled or supervised by and acting as an agency or instrumentality of
     the United States of America the payment of which is unconditionally
     guaranteed as a full faith and credit obligation by the United States of
     America, which, in either case, are not callable or redeemable at the
     option of the issuer thereof at any time prior to the Stated Maturity of
     the Securities, and shall also include a depository receipt issued by a
     bank or trust company as custodian with respect to any such U.S. Government
     Obligation or a specific payment of interest on or principal of any such
     U.S. Government Obligation held by such custodian for the account of the
     holder of a depository receipt; provided that (except as required by law)
     such custodian is not authorized to make any deduction from the amount
     payable to the holder of such depository receipt from any amount received
     by the custodian in respect of the U.S. Government Obligation or the
     specific payment of interest on or principal of the U.S. Government
     Obligation evidenced by such depository receipt.

              "U.S. Person" has the meaning ascribed thereto in Rule 902 under
     the Securities Act.

              "U.S. Physical Securities" has the meaning provided in Section
     2.01.

              "Unrestricted Subsidiary" means (i) any Subsidiary of the
     Guarantor that at the time of determination shall be designated an
     Unrestricted Subsidiary by the Board of Directors in the manner provided
     below and (ii) any Subsidiary of an Unrestricted Subsidiary. The Board of
     Directors may designate any Restricted Subsidiary of the Guarantor
     (including any newly acquired or newly formed Subsidiary of the Guarantor),
     other than the Company or a Subsidiary that has given a Subsidiary
     Guarantee, to be an Unrestricted Subsidiary unless such Subsidiary owns any
     Capital Stock of, or owns or holds any Lien on any property of, the
     Guarantor or any Restricted Subsidiary; provided that either (A) the
     Subsidiary to be so designated has total assets of $1,000 or less or (B) if
     such Subsidiary has assets greater than $1,000, that such designation would
     be permitted under Section 4.04. The Board of Directors may designate any
     Unrestricted Subsidiary to be a Restricted Subsidiary of the Guarantor;
     provided that immediately after giving effect to such designation (x) the
     Guarantor could Incur $1.00 of additional Indebtedness under the first
     paragraph of Section 4.03(a) and (y) no Default or Event of Default shall
     have occurred and be continuing. Any such designation by the Board of
     Directors shall be evidenced to the Trustee by promptly filing with the
     Trustee a copy of the Board Resolution giving effect to such designation
     and an Officers' Certificate certifying that such designation complied with
     the foregoing provisions. 

              "Voting Stock" means, with respect to any Person, Capital Stock
     of any class or kind ordinarily having the power to vote for the election
     of directors, managers or other voting members of the governing body of
     such Person. 

              "Wholly Owned" means, with respect to any Subsidiary of any
     Person, such Subsidiary if 98% or more of the outstanding Capital Stock in
     such Subsidiary (other than any director's qualifying shares or Investments
     by foreign nationals mandated by applicable law) is owned by such Person or
     one or more Wholly Owned Subsidiaries of such Person. 

              "Zycom" means Zycom Corporation, an Alberta, Canada corporation. 

              SECTION 1.02.  Incorporation by Reference of Trust Indenture Act. 
                             -------------------------------------------------
     Whenever this Indenture refers to a provision of the TIA, the provision is
     incorporated by reference in and made a part of this Indenture.  The
     following TIA terms used in this Indenture have the following meanings:

              "indenture securities" means the Securities;

              "indenture security holder" means a Holder or a Securityholder;

              "indenture to be qualified" means this Indenture;

              "indenture trustee" or "institutional trustee" means the Trustee;
         and

              "obligor" on the indenture securities means the Company, the
         Guarantor or any other obligor on the Securities.

              All other TIA terms used in this Indenture that are defined by
     the TIA, defined by TIA reference to another statute or defined by a rule
     of the Commission and not otherwise defined herein have the meanings
     assigned to them therein.

              SECTION 1.03.  Rules of Construction.  Unless the context 
                             ---------------------
     otherwise requires:

              (i)  a term has the meaning assigned to it;

              (ii) an accounting term not otherwise defined has the meaning
         assigned to it in accordance with GAAP;

              (iii)     "or" is not exclusive;

              (iv) words in the singular include the plural, and words in the
         plural include the singular;

              (v)  provisions apply to successive events and transactions;

              (vi) "herein," "hereof" and other words of similar import refer
         to this Indenture as a whole and not to any particular Article,
         Section or other subdivision; and

              (vii)     all references to Sections or Articles refer to
         Sections or Articles of this Indenture unless otherwise indicated.


                                     ARTICLE TWO
                                    THE SECURITIES

              SECTION 2.01.  Form and Dating.  The Securities and the Trustee's
                             ---------------
     certificate of authentication shall be substantially in the form annexed
     hereto as Exhibit A.  The Securities may have such appropriate insertions,
     omissions, substitutions and other variations as are required or permitted
     by the Indenture and may have letters, notations, legends or endorsements
     required by law, stock exchange agreements to which the Company is subject
     or usage.  Any portion of the text of any Security may be set forth on the
     reverse thereof, with an appropriate reference thereto on the face of the
     Security.  The Company shall approve the form of the Securities and any
     notation, legend or endorsement on the Securities.  Each Security shall be
     dated the date of its authentication.

              The terms and provisions contained in the form of the Securities
     annexed hereto as Exhibit A shall constitute, and are hereby expressly
     made, a part of this Indenture.  Each of the Company, the Guarantor and the
     Trustee, by its execution and delivery of this Indenture, expressly agrees
     to the terms and provisions of the Securities applicable to it and to be
     bound thereby.

              Securities offered and sold in reliance on Rule 144A shall be
     issued in the form of one or more permanent global Securities in registered
     form, substantially in the form set forth in Exhibit A (the "U.S. Global 
                                                                 ------------
     Security"), deposited with the Trustee, as custodian for the Depositary, 
     --------
     duly executed by the Company and authenticated by the Trustee as
     hereinafter provided.  The aggregate principal amount at maturity of a U.S.
     Global Security may from time to time be increased or decreased by
     adjustments made on the records of the Trustee, as custodian for the
     Depositary or its nominee, as hereinafter provided.

              Securities offered and sold in offshore transactions in reliance
     on Regulation S shall be issued in the form of one or more single permanent
     global Securities in registered form substantially in the form set forth in
     Exhibit A (the "Offshore Global Security") deposited with the Trustee, as 
                     ------------------------
     custodian for the Depositary, duly executed by the Company and
     authenticated by the Trustee as hereinafter provided.  The aggregate
     principal amount at maturity of an Offshore Global Security may from time
     to time be increased or decreased by adjustments made in the records of the
     Trustee, as custodian for the Depositary or its nominee, as herein
     provided.

              Securities which are offered and sold to Institutional Accredited
     Investors which are not QIBs (excluding Non-U.S. Persons) shall be issued
     in the form of permanent certificated Securities in registered form in
     substantially the form set forth in Exhibit A (the "U.S. Physical 
                                                         --------------
     Securities").  Securities issued pursuant to Section 2.07 in exchange for 
     ----------
     interests in a U.S. Global Security or an Offshore Global Security shall be
     in the form of U.S. Physical Securities or in the form of permanent
     certificated Securities in registered form substantially in the form set
     forth in Exhibit A (the "Offshore Physical Securities"), respectively.
                              ----------------------------

              The Offshore Physical Securities and U.S. Physical Securities are
     sometimes collectively herein referred to as the "Physical Securities".  
                                                       -------------------
     U.S. Global Securities and Offshore Global Securities are sometimes
     referred to as the "Global Securities".
                         -----------------

              The definitive Securities shall be typed, printed, lithographed
     or engraved or produced by any combination of these methods or may be
     produced in any other manner permitted by the rules of any securities
     exchange on which the Securities may be listed, all as determined by the
     officers executing such Securities, as evidenced by their execution of such
     Securities.

              SECTION 2.02.  Restrictive Legends.  Unless and until a Security 
                              -------------------
     is exchanged for an Exchange Security or otherwise disposed of in
     connection with an effective Registration Statement pursuant to the
     Registration Rights Agreement, (i) each U.S. Global Security and each U.S.
     Physical Security shall bear the legend, set forth below on the face
     thereof and (ii) each Offshore Physical Security and the Offshore Global
     Security shall bear the legend set forth below on the face thereof until at
     least 41 days after the Closing Date and receipt by the Company and the
     Trustee of a certificate substantially in the form of Exhibit B hereto.

         THIS NOTE HAS NOT BEEN REGISTERED UNDER THE U.S. SECURITIES ACT OF
         1933, AS AMENDED (THE "SECURITIES ACT"), AND, ACCORDINGLY, MAY NOT BE
         OFFERED OR SOLD WITHIN THE UNITED STATES OR TO, OR FOR THE ACCOUNT OR
         BENEFIT OF, U.S. PERSONS EXCEPT AS SET FORTH IN THE FOLLOWING
         SENTENCE.  BY ITS ACQUISITION HEREOF, THE HOLDER (1) REPRESENTS THAT
         (A) IT IS A "QUALIFIED INSTITUTIONAL BUYER" (AS DEFINED IN RULE 144A
         UNDER THE SECURITIES ACT), (B) IT IS NOT A U.S. PERSON AND IS
         ACQUIRING THIS NOTE IN AN OFFSHORE TRANSACTION IN COMPLIANCE WITH
         REGULATION S UNDER THE SECURITIES ACT, OR (C) IT IS AN INSTITUTIONAL
         "ACCREDITED INVESTOR" (AS DEFINED IN RULE 501(a)(1), (2), (3) OR (7)
         OF REGULATION D UNDER THE SECURITIES ACT) (AN "INSTITUTIONAL
         ACCREDITED INVESTOR"), (2) AGREES THAT IT WILL NOT, WITHIN THE TIME
         PERIOD REFERRED TO IN RULE 144(k) UNDER THE SECURITIES ACT AS IN
         EFFECT ON THE  DATE OF THE TRANSFER OF THIS NOTE, RESELL OR OTHERWISE
         TRANSFER THIS NOTE EXCEPT (A) TO THE COMPANY OR ANY SUBSIDIARY
         THEREOF, (B) INSIDE THE UNITED STATES TO A QUALIFIED INSTITUTIONAL
         BUYER IN COMPLIANCE WITH RULE 144A UNDER THE SECURITIES ACT,
         (C) OUTSIDE THE UNITED STATES IN AN OFFSHORE TRANSACTION IN COMPLIANCE
         WITH RULE 904 UNDER THE SECURITIES ACT, (D) PURSUANT TO THE EXEMPTION
         FROM REGISTRATION PROVIDED BY RULE 144 UNDER THE SECURITIES ACT (IF
         AVAILABLE), (E) INSIDE THE UNITED STATES TO AN INSTITUTIONAL
         ACCREDITED INVESTOR THAT, PRIOR TO SUCH TRANSFER, FURNISHES TO THE
         TRUSTEE A SIGNED LETTER CONTAINING CERTAIN REPRESENTATIONS AND
         AGREEMENTS RELATING TO THE RESTRICTIONS ON TRANSFER OF THIS NOTE (THE
         FORM OF WHICH LETTER CAN BE OBTAINED FROM THE TRUSTEE) AND IF SUCH
         TRANSFER IS IN RESPECT OF AN ACCRETED VALUE OF NOTES AT THE TIME OF
         TRANSFER OF LESS THAN $250,000, AN OPINION OF COUNSEL ACCEPTABLE TO
         THE COMPANY THAT SUCH TRANSFER IS IN COMPLIANCE WITH THE SECURITIES
         ACT OR (F) AFTER REGISTRATION UNDER THE SECURITIES ACT, AND (3) AGREES
         THAT IT WILL DELIVER TO EACH PERSON TO WHOM THIS NOTE IS TRANSFERRED A
         NOTICE SUBSTANTIALLY TO THE EFFECT OF THIS LEGEND.  IN CONNECTION WITH
         ANY TRANSFER OF THIS NOTE WITHIN THE TIME PERIOD REFERRED TO ABOVE,
         THE HOLDER MUST CHECK THE APPROPRIATE BOX SET FORTH ON THE REVERSE
         HEREOF RELATING TO THE MANNER OF SUCH TRANSFER AND SUBMIT THIS
         CERTIFICATE TO THE TRUSTEE.  AS USED HEREIN, THE TERMS "OFFSHORE
         TRANSACTION", "UNITED STATES" AND "U.S. PERSON" HAVE THE MEANINGS
         GIVEN TO THEM BY REGULATION S UNDER THE SECURITIES ACT.  THE INDENTURE
         CONTAINS A PROVISION REQUIRING THE TRUSTEE TO REFUSE TO REGISTER ANY
         TRANSFER OF THIS NOTE IN VIOLATION OF THE FOREGOING RESTRICTIONS.

              Each Global Security, whether or not an Exchange Security, shall
     also bear the following legend on the face thereof:

         UNLESS THIS NOTE IS PRESENTED BY AN AUTHORIZED REPRESENTATIVE OF
         THE DEPOSITORY TRUST COMPANY TO THE COMPANY OR ITS AGENT FOR
         REGISTRATION OF TRANSFER, EXCHANGE OR PAYMENT, AND ANY NOTE ISSUED
         IS REGISTERED IN THE NAME OF CEDE & CO. OR TO SUCH OTHER ENTITY AS
         IS REQUESTED BY AN AUTHORIZED REPRESENTATIVE OF THE DEPOSITORY
         TRUST COMPANY OR SUCH OTHER REPRESENTATIVE OF THE DEPOSITORY TRUST
         COMPANY OR SUCH OTHER NAME AS IS REQUESTED BY AN AUTHORIZED
         REPRESENTATIVE OF THE DEPOSITORY TRUST COMPANY (AND ANY PAYMENT
         HEREON IS MADE TO CEDE & CO. OR TO SUCH OTHER ENTITY AS IS
         REQUESTED BY AN AUTHORIZED REPRESENTATIVE OF THE DEPOSITORY TRUST
         COMPANY), ANY TRANSFER, PLEDGE OR OTHER USE HEREOF FOR VALUE OR
         OTHERWISE BY OR TO ANY PERSON IS WRONGFUL SINCE THE REGISTERED
         OWNER HEREOF, CEDE & CO., HAS AN INTEREST HEREIN.

         TRANSFERS OF THIS GLOBAL SECURITY SHALL BE LIMITED TO TRANSFERS IN
         WHOLE, BUT NOT IN PART, TO NOMINEES OF CEDE & CO. OR TO A
         SUCCESSOR THEREOF OR SUCH SUCCESSOR'S NOMINEE AND TRANSFERS OF
         PORTIONS OF THIS GLOBAL SECURITY SHALL BE LIMITED TO TRANSFERS
         MADE IN ACCORDANCE WITH THE RESTRICTIONS SET FORTH IN SECTION 2.08
         OF THE INDENTURE.

               SECTION 2.03.  Execution, Authentication and Denominations.  The 
                              -------------------------------------------
     initial original issuance under this Indenture shall be an amount equal to
     $176,000,000 aggregate principal amount at maturity, and, subject to
     Article Four, the Company may from time to time issue additional
     Securities, the aggregate principal amount of which additional Securities
     that may be authenticated and delivered under this Indenture is unlimited.

               The Securities shall be executed by an Officer of the Company
     listed in clause (i) of the definition of Officer herein and attested by an
     Officer of the Company listed in clause (i) or clause (ii) of the
     definition of Officer herein.  The signature of any of these Officers on
     the Securities may be by facsimile or manual signature in the name and on
     behalf of the Company.

               If an Officer whose signature is on a Security no longer holds
     that office at the time the Trustee or authenticating agent authenticates
     the Security, the Security shall be valid nevertheless.

               A Security shall not be valid until the Trustee or authenticating
     agent manually signs the certificate of authentication on the Security. 
     The signature shall be conclusive evidence that the Security has been
     authenticated under this Indenture.

               Pursuant to and based upon a Company Order, the Trustee or an
     authenticating agent shall authenticate for original issue Securities
     registered in the name of the Depositary or the nominee of the Depositary
     or other Person, as specified in the Company Order, and shall deliver such
     Global Securities to the Depositary or pursuant to the Depositary's
     instructions or to such other Person; provided that the Trustee shall be
     entitled to receive an Officers' Certificate and an Opinion of Counsel of
     the Company in connection with such authentication of Securities.  The
     Opinion of Counsel shall, if requested by the Trustee, be to the effect
     that:

               (a)  the form and terms of such Securities have been established
          by or pursuant to a Board Resolution or an indenture supplemental
          hereto in conformity with the provisions of this Indenture;

               (b)  such supplemental indenture, if any, when executed and
          delivered by the Company, the Guarantor and the Trustee, will
          constitute a valid and binding obligation of the Company and the
          Guarantor;

               (c)  such Securities, when authenticated and delivered by the
          Trustee and issued by the Company in the manner and subject to any
          conditions specified in such Opinion of Counsel, will constitute valid
          and binding obligations of the Company in accordance with their terms
          and will be entitled to the benefits of this Indenture, subject to
          bankruptcy, insolvency, fraudulent transfer, reorganization,
          moratorium and similar laws of general applicability relating to or
          affecting creditors' rights and to general equity principles; and

               (d)  the Company has been duly incorporated in, and is a validly
          existing corporation in good standing under the laws of, the State of
          Colorado.

     Such Company Order shall specify the amount of Securities to be
     authenticated and the date on which the original issue of Securities is to
     be authenticated.  The aggregate principal amount at maturity of Securities
     outstanding at any time may not exceed the amount set forth above except
     for Securities authenticated and delivered upon registration of transfer
     of, or in exchange for, or in lieu of, other Securities pursuant to
     Section 2.06, 2.09, 2.10 or 2.11.

               The Trustee may appoint an authenticating agent to authenticate
     Securities.  An authenticating agent may authenticate Securities whenever
     the Trustee may do so.  Each reference in this Indenture to authentication
     by the Trustee includes authentication by such authenticating agent.  An
     authenticating agent has the same rights as an Agent to deal with the
     Company or an Affiliate of the Company.

               The Securities shall be issuable only in registered form without
     coupons and only in denominations of $1,000 in principal amount at maturity
     and any integral multiple of $1,000 in excess thereof.

               SECTION 2.04.  Registrar and Paying Agent.  The Company shall 
                               --------------------------
     maintain an office or agency where Securities may be presented for
     registration of transfer or for exchange (the "Registrar"), an office or
                                                    ---------
     agency where Securities may be presented for payment (the "Paying Agent")
                                                                ------------
     and an office or agency where notices and demands to or upon the Company in
     respect of the Securities and this Indenture may be served, which shall be
     in the Borough of Manhattan, The City of New York.  The Company shall cause
     the Registrar to keep a register of the Securities and of their transfer
     and exchange (the "Security Register").  The Company may have one or more 
                        -----------------
     co-Registrars and one or more additional Paying Agents.

               The Company shall enter into an appropriate agency agreement with
     any Agent not a party to this Indenture.  The agreement shall implement the
     provisions of this Indenture that relate to such Agent.  The Company shall
     give prompt written notice to the Trustee of the name and address of any
     such Agent and any change in the address of such Agent.  If the Company
     fails to maintain a Registrar, Paying Agent and/or agent for service of
     notices and demands, the Trustee shall act as such Registrar, Paying Agent
     and/or agent for service of notices and demands for so long as such failure
     shall continue.  The Company may remove any Agent upon written notice to
     such Agent and the Trustee; provided that no such removal shall become
     effective until (i) the acceptance of an appointment by a successor Agent
     to such Agent as evidenced by an appropriate agency agreement entered into
     by the Company and such successor Agent and delivered to the Trustee or
     (ii) notification to the Trustee that the Trustee shall serve as such Agent
     until the appointment of a successor Agent in accordance with clause (i) of
     this proviso.  The Company, any Subsidiary of the Company, or any Affiliate
     of any of them may act as Paying Agent, Registrar or co-Registrar, and/or
     agent for service of notice and demands; provided, however, that neither
     the Company, a Subsidiary of the Company nor an Affiliate of any of them
     shall act as Paying Agent in connection with the defeasance of the
     Securities or the discharge of this Indenture under Article Eight.

               The Company initially appoints the Trustee as Registrar, Paying
     Agent, authenticating agent and agent for service of notice and demands. 
     If, at any time, the Trustee is not the Registrar, the Registrar shall make
     available to the Trustee on or before each Interest Payment Date and at
     such other times as the Trustee may reasonably request, the names and
     addresses of the Holders as they appear in the Security Register.

               SECTION 2.05.  Paying Agent to Hold Money in Trust.  Not later 
                              -----------------------------------
     than 10:00 a.m. New York City time on each due date of the principal of,
     premium, if any, and interest on any Securities, the Company shall deposit
     with the Paying Agent money in immediately available funds sufficient to
     pay such principal, premium, if any, and interest so becoming due.  The
     Company shall require each Paying Agent, if any, other than the Trustee to
     agree in writing that such Paying Agent shall hold in trust for the benefit
     of the Holders or the Trustee all money held by the Paying Agent for the
     payment of principal of, premium, if any, and interest on the Securities
     (whether such money has been paid to it by the Company or any other obligor
     on the Securities), and that such Paying Agent shall promptly notify the
     Trustee of any default by the Company (or any other obligor on the
     Securities) in making any such payment.  The Company at any time may
     require a Paying Agent to pay all money held by it to the Trustee and
     account for any funds disbursed, and the Trustee may at any time during the
     continuance of any payment default, upon written request to a Paying Agent,
     require such Paying Agent to pay all money held by it to the Trustee and to
     account for any funds disbursed.  Upon doing so, the Paying Agent shall
     have no further liability for the money so paid over to the Trustee.  If
     the Company or any Subsidiary of the Company or any Affiliate of any of
     them acts as Paying Agent, it will, on or before each due date of any
     principal of, premium, if any, or interest on the Securities, segregate and
     hold in a separate trust fund for the benefit of the Holders a sum of money
     sufficient to pay such principal, premium, if any, or interest so becoming
     due until such sum of money shall be paid to such Holders or otherwise
     disposed of as provided in this Indenture, and will promptly notify the
     Trustee of its action or failure to act as required by this Section 2.05.

               SECTION 2.06.  Transfer and Exchange.  The Securities are 
                              ---------------------
     issuable only in registered form.  A Holder may transfer a Security by
     written application to the Registrar stating the name of the proposed
     transferee and otherwise complying with the terms of this Indenture.  No
     such transfer shall be effected until, and such transferee shall succeed to
     the rights of a Holder only upon registration of the transfer by the
     Registrar in the Security Register.  Prior to the registration of any
     transfer by a Holder as provided herein, the Company, the Trustee, and any
     agent of the Company shall treat the person in whose name the Security is
     registered as the owner thereof for all purposes whether or not the
     Security shall be overdue, and neither the Company, the Trustee, nor any
     such agent shall be affected by notice to the contrary.  Furthermore, any
     Holder of a Global Security shall, by acceptance of such Global Security,
     agree that transfers of beneficial interests in such Global Security may be
     effected only through a book-entry system maintained by the Depositary (or
     its agent), and that ownership of a beneficial interest in the Security
     shall be required to be reflected in a book entry.  When Securities are
     presented to the Registrar or a co-Registrar with a request to register the
     transfer or to exchange them for an equal principal amount at maturity of
     Securities of other authorized denominations (including on exchange of
     Securities for Exchange Securities), the Registrar shall register the
     transfer or make the exchange as requested if its requirements for such
     transactions are met; provided that no exchanges of Securities for Exchange
     Securities shall occur until a Registration Statement shall have been
     declared effective by the Commission and that any Securities that are
     exchanged for Exchange Securities shall be cancelled by the Trustee.  To
     permit registrations of transfers and exchanges in accordance with the
     terms, conditions and restrictions hereof, the Company shall execute and
     the Trustee shall authenticate Securities at the Registrar's request.  No
     service charge shall be made to any Holder for any registration of transfer
     or exchange or redemption of the Securities, but the Company may require
     payment of a sum sufficient to cover any transfer tax or similar
     governmental charge payable in connection therewith (other than any such
     transfer taxes or other similar governmental charge payable upon transfers,
     exchanges or redemptions pursuant to Section 2.11, 3.08, 4.11, 4.12 or
     9.04).

               The Registrar shall not be required (i) to issue, register the
     transfer of or exchange any Security during a period beginning at the
     opening of business 15 days before the day of the mailing of a notice of
     redemption of Securities selected for redemption under Section 3.03 or
     Section 3.08 and ending at the close of business on the day of such
     mailing, or (ii) to register the transfer of or exchange any Security so
     selected for redemption in whole or in part, except the unredeemed portion
     of any Security being redeemed in part.

               SECTION 2.07.  Book-Entry Provisions for Global Securities. 
                              -------------------------------------------
      (a)  Each U.S. Global Security and Offshore Global Security initially
     shall (i) be registered in the name of the Depositary for such Global
     Securities or the nominee of such Depositary, (ii) be delivered to the
     Trustee as custodian for such Depositary and (iii) bear legends as set
     forth in Section 2.02.

               Members of, or participants in, the Depositary ("Agent Members")
                                                                -------------
     shall have no rights under this Indenture with respect to any Global
     Security held on their behalf by the Depositary, or the Trustee as its
     custodian, or under any Global Security, and the Depositary may be treated
     by the Company, the Guarantor, the Trustee and any agent of the Company,
     the Guarantor or the Trustee as the absolute owner of such Global Security
     for all purposes whatsoever.  Notwithstanding the foregoing, nothing herein
     shall prevent the Company, the Guarantor, the Trustee or any agent of the
     Company, the Guarantor or the Trustee, from giving effect to any written
     certification, proxy or other authorization furnished by the Depositary or
     impair, as between the Depositary and its Agent Members, the operation of
     customary practices governing the exercise of the rights of a beneficial
     owner of any Security.

               (b)  Transfers of a Global Security shall be limited to transfers
     of such  Global Security in whole, but not in part, to the Depositary, its
     successors or their respective nominees.  Interests of beneficial owners in
     a Global Security may be transferred in accordance with the applicable
     rules and procedures of the Depositary and the provisions of Section 2.08. 
     In addition, Offshore Physical Securities shall be transferred to all
     beneficial owners in exchange for their beneficial interests in a U.S.
     Global Securities or an Offshore Global Security, respectively, if (i) the
     Depositary notifies the Company that it is unwilling or unable to continue
     as Depositary for the U.S. Global Securities or the Offshore Global
     Securities, as the case may be, and a successor depositary is not appointed
     by the Company within 90 days of such notice or (ii) an Event of Default
     has occurred and is continuing and the Registrar has received a request to
     the foregoing effect from the Depositary.

               (c)  Any beneficial interest in one of the Global Securities that
     is transferred to a person who takes delivery in the form of an interest in
     the other Global Security will, upon transfer, cease to be an interest in
     such Global Security and become an interest in the other Global Security
     and, accordingly, will thereafter be subject to all transfer restrictions,
     if any, and other procedures applicable to beneficial interests in such
     other Global Security for as long as it remains such an interest.

               (d)  In connection with any transfer pursuant to paragraph (b) of
     this Section of a portion of the beneficial interests in a U.S. Global
     Security to beneficial owners who are required to hold U.S. Physical
     Securities, the Registrar shall reflect on its books and records the date
     and a decrease in the principal amount at maturity of such U.S. Global
     Security in an amount equal to the principal amount at maturity of the
     beneficial interest in such U.S. Global Security to be transferred, and the
     Company shall execute, and the Trustee shall authenticate and deliver, one
     or more U.S. Physical Securities of like tenor and amount.

               (e)  In connection with the transfer of the entire set of U.S.
     Global Securities or Offshore Global Securities to beneficial owners
     pursuant to paragraph (b) of this Section, the U.S. Global Securities or
     Offshore Global Securities, as the case may be, shall be deemed to be
     surrendered to the Trustee for cancellation, and the Company shall execute,
     and the Trustee shall authenticate and deliver, to each beneficial owner
     identified by the Depositary in exchange for its beneficial interest in the
     U.S. Global Securities or Offshore Global Securities, as the case may be,
     an equal aggregate principal amount at maturity of U.S. Physical Securities
     or Offshore Physical Securities, as the case may be, of authorized
     denominations.

               (f)  Any U.S. Physical Security delivered in exchange for an
     interest in a U.S. Global Security pursuant to paragraph (b) or (d) of this
     Section shall, except as otherwise provided by paragraph (f)(i)(x) and
     paragraph (d) of Section 2.08, bear the legend regarding transfer
     restrictions applicable to the U.S. Physical Security set forth in
     Section 2.02.

               (g)  The registered holder of a Global Security may grant proxies
     and otherwise authorize any person, including Agent Members and persons
     that may hold interests through Agent Members, to take any action which a
     Holder is entitled to take under this Indenture or the Securities.

               (h)  QIBs that are beneficial owners of interests in a Global
     Security may receive Physical Securities (which shall bear the Private
     Placement Legend if required by Section 2.02) in accordance with the
     procedures of the Depositary.  In connection with the execution,
     authentication and delivery of such Physical Securities, the Registrar
     shall reflect on its books and records a decrease in the principal amount
     of the relevant Global Security equal to the principal amount of such
     Physical Securities and the Company shall execute and the Trustee shall
     authenticate and deliver one or more Physical Securities having an equal
     aggregate principal amount.

               SECTION 2.08.  Special Transfer Provisions.  Unless and until a 
                            ---------------------------
     Security is exchanged for an Exchange Security in connection with an
     effective Registration Statement pursuant to the Registration Rights
     Agreement, the following provisions shall apply:

               (a)  Transfers to QIBs.  The following provisions shall apply 
                    -----------------
     with respect to the registration of any proposed transfer of a U.S.
     Physical Security or an interest in a U.S. Global Security to a QIB
     (excluding Non-U.S. Persons):

               (i)  If the Security to be transferred consists of (x) U.S.
          Physical Securities, the Registrar shall register the transfer if such
          transfer is being made by a proposed transferor who has checked the
          box provided for on the form of Security stating, or has otherwise
          advised the Company and the Registrar in writing, that the sale has
          been made in compliance with the provisions of Rule 144A to a
          transferee who has signed the certification provided for on the form
          of Security stating, or has otherwise advised the Company and the
          Registrar in writing, that it is purchasing the Security for its own
          account or an account with respect to which it exercises sole
          investment discretion and that it and any such account is a QIB within
          the meaning of Rule 144A, and is aware that the sale to it is being
          made in reliance on Rule 144A and acknowledges that it has received
          such information regarding the Company as it has requested pursuant to
          Rule 144A or has determined not to request such information and that
          it is aware that the transferor is relying upon its foregoing
          representations in order to claim the exemption from registration
          provided by Rule 144A or (y) an interest in a U.S. Global Security,
          the transfer of such interest may be effected only through the book
          entry system maintained by the Depositary.

               (ii) If the proposed transferor is an Agent Member, and the
          Security to be transferred consists of U.S. Physical Securities, upon
          receipt by the Registrar of the documents referred to in clause (i)
          and instructions given in accordance with the Depositary's and the
          Registrar's procedures, the Registrar shall reflect on its books and
          records the date and an increase in the principal amount at maturity
          of such U.S. Global Security in an amount equal to the principal
          amount at maturity of the U.S. Physical Securities to be transferred,
          and the Trustee shall cancel the Physical Security so transferred.

               (b)  Transfers of Interests in Offshore Global Securities or 
                    --------------------------------------------------------
     Offshore Physical Securities to U.S. Persons.  The following provisions 
     --------------------------------------------
     shall apply with respect to any transfer of interests in Offshore Global
     Securities or Offshore Physical Securities to U.S. Persons:  

               (i)  prior to the removal of the Private Placement Legend from
          Offshore Global Securities or Offshore Physical Securities pursuant to
          Section 2.02, the Registrar shall refuse to register such transfer;
          and 

               (ii) after such removal, the Registrar shall register the
          transfer of any such Security without requiring any additional
          certification.

               (c)  Transfers to Non-U.S. Persons at Any Time.  The following 
                    -----------------------------------------
     provisions shall apply with respect to any transfer of a Security to a Non-
     U.S. Person:

               (i)  The Registrar shall register any proposed transfer to any
          Non-U.S. Person if the Security to be transferred is a U.S. Physical
          Security or an interest in a U.S. Global Security only upon receipt of
          a certificate substantially in the form of Exhibit C from the proposed
          transferor.

               (ii) (a) If the proposed transferor is an Agent Member holding a
          beneficial interest in a U.S. Global Security, upon receipt by the
          Registrar of (x) the documents required by paragraph (i) and
          (y) instructions in accordance with the Depositary's and the
          Registrar's procedures, the Registrar shall reflect on its books and
          records the date and a decrease in the principal amount at maturity of
          such U.S. Global Security in an amount equal to the principal amount
          at maturity of the beneficial interest in the U.S. Global Security to
          be transferred, and (b) if the proposed transferee is an Agent Member,
          upon receipt by the Registrar of instructions given in accordance with
          the Depositary's and the Registrar's procedures, the Registrar shall
          reflect on its books and records the date and an increase in the
          principal amount at maturity of such Offshore Global Security in an
          amount equal to the principal amount at maturity of the U.S. Physical
          Securities or the U.S. Global Securities, as the case may be, to be
          transferred, and the Trustee shall cancel the Physical Security, if
          any, so transferred or decrease the amount of the U.S. Global
          Securities.

               (d)  Private Placement Legend.  Upon the transfer, exchange or 
                    ------------------------
     replacement of Securities not bearing the Private Placement Legend, the
     Registrar shall deliver Securities that do not bear the Private Placement
     Legend.  Upon the transfer, exchange or replacement of Securities bearing
     the Private Placement Legend, the Registrar shall deliver only Securities
     that bear the Private Placement Legend unless either (i) the Private
     Placement Legend is no longer required by Section 2.02, (ii) there is
     delivered to the Registrar an Opinion of Counsel reasonably satisfactory to
     the Company and the Trustee to the effect that neither such legend nor the
     related restrictions on transfer are required in order to maintain
     compliance with the provisions of the Securities Act or (iii) the Private
     Placement Legend is no longer required by Section 2.02.

               (e)  General.  By its acceptance of any Security bearing the 
                    -------
     Private Placement Legend, each Holder of such a Security acknowledges the
     restrictions on transfer of such Security set forth in this Indenture and
     in the Private Placement Legend and agrees that it will transfer such
     Security only as provided in this Indenture.  The Registrar shall not
     register a transfer of any Security unless such transfer complies with the
     restrictions on transfer of such Security set forth in this Indenture.  In
     connection with any transfer of Securities to an Institutional Accredited
     Investor, each Holder agrees by its acceptance of the Securities to furnish
     the Registrar or the Company such certifications, legal opinions or other
     information as either of them may reasonably require to confirm that such
     transfer is being made pursuant to an exemption from, or a transaction not
     subject to, the registration requirements of the Securities Act; provided
     that the Registrar shall not be required to determine (but may rely on a
     determination made by the Company with respect to) the sufficiency of any
     such certifications, legal opinions or other information.

               (f)  Transfers to Non-QIB Institutional Accredited Investors.  
                    -------------------------------------------------------
     The following provisions shall apply with respect to the registration of
     any proposed transfer of a Security to any Institutional Accredited
     Investor which is not a QIB (excluding Non-U.S. Persons):

               (i)  The Registrar shall register the transfer of any Security,
          whether or not such Security bears the Private Placement Legend, if
          (x) the requested transfer is after the time period referred to in
          Rule 144(k) under the Securities Act as in effect with respect to such
          transfer or (y) the proposed transferee has delivered to the Registrar
          (A) a certificate substantially in the form of Exhibit D hereto and
          (B) if the aggregate Accreted Value of the Securities being
          transferred is less than $250,000 at the time of such transfer, an
          Opinion of Counsel acceptable to the Company that such transfer is in
          compliance with the Securities Act.

               (ii) If the proposed transferor is an Agent Member holding a
          beneficial interest in a U.S. Global Security, upon receipt by the
          Registrar of (x) the documents, if any, required by paragraph (i) and
          (y) instructions given in accordance with the Depositary's and the
          Registrar's procedures, the Registrar shall reflect on its books and
          records the date and a decrease in the principal amount of such U.S.
          Global Security in an amount equal to the principal amount of the
          beneficial interest in the U.S. Global Security to be transferred, and
          the Company shall execute, and the Trustee shall authenticate and
          deliver, one or more U.S. Physical Securities of like tenor and
          amount.

               The Registrar shall retain copies of all letters, notices and
     other written communications received pursuant to Section 2.07 or this
     Section 2.08.  The Company shall have the right to inspect and make copies
     of all such letters, notices or other written communications at any
     reasonable time upon the giving of reasonable written notice to the
     Registrar.

               SECTION 2.09.  Replacement Securities.  If a mutilated Security 
                            ----------------------
     is surrendered to the Trustee or if the Holder claims that the Security has
     been lost, destroyed or wrongfully taken, the Company shall issue and the
     Trustee shall authenticate a replacement Security of like tenor and
     principal amount and bearing a number not contemporaneously outstanding;
     provided that the requirements of the second paragraph of Section 2.10 are
     met.  If required by the Trustee or the Company, an indemnity bond must be
     furnished that is sufficient in the judgment of both the Trustee and the
     Company to protect the Company, the Trustee or any Agent from any loss that
     any of them may suffer if a Security is replaced.  The Company may charge
     such Holder for its expenses and the expenses of the Trustee in replacing a
     Security.  In case any such mutilated, lost, destroyed or wrongfully taken
     Security has become or is about to become due and payable, the Company in
     its discretion may pay such Security instead of issuing a new Security in
     replacement thereof.

               Every replacement Security is an additional obligation of the
     Company and shall be entitled to the benefits of this Indenture.

               SECTION 2.10.  Outstanding Securities.  Securities outstanding at
                            ----------------------
     any time are all Securities that have been authenticated by the Trustee
     except for those cancelled by it, those delivered to it for cancellation
     and those described in this Section 2.10 as not outstanding (the
     "Outstanding Securities").
      ----------------------

               If a Security is replaced pursuant to Section 2.09, it ceases to
     be outstanding unless and until the Trustee and the Company receive proof
     reasonably satisfactory to them that the replaced Security is held by a
     bona fide purchaser.

               If the Paying Agent (other than the Company or an Affiliate of
     the Company) holds on the maturity date money sufficient to pay Securities
     payable on that date, then on and after that date such Securities cease to
     be outstanding and interest on them shall cease to accrue.

               A Security does not cease to be outstanding because the Company
     or one of its Affiliates holds such Security, provided, however, that, in
     determining whether the Holders of the requisite principal amount at
     maturity of the outstanding Securities have given any request, demand,
     authorization, direction, notice, consent or waiver hereunder, Securities
     owned by the Company or any other obligor upon the Securities or any
     Affiliate of the Company or of such other obligor shall be disregarded and
     deemed not to be outstanding, except that, in determining whether the
     Trustee shall be protected in relying upon any such request, demand,
     authorization, direction, notice, consent or waiver, only Securities which
     the Trustee knows to be so owned shall be so disregarded.  Securities so
     owned which have been pledged in good faith may be regarded as outstanding
     if the pledgee establishes to the satisfaction of the Trustee the pledgee's
     right so to act with respect to such Securities and that the pledgee is not
     the Company or any other obligor upon the Securities or any Affiliate of
     the Company or of such other obligor.

               SECTION 2.11.  Temporary Securities.  Until definitive Securities
                            --------------------
     are ready for delivery, the Company may prepare and the Trustee shall
     authenticate temporary Securities.  Temporary Securities shall be
     substantially in the form of definitive Securities but may have insertions,
     substitutions, omissions and other variations determined to be appropriate
     by the Officers executing the temporary Securities, as evidenced by their
     execution of such temporary Securities.  If temporary Securities are
     issued, the Company will cause definitive Securities to be prepared without
     unreasonable delay.  After the preparation of definitive Securities, the
     temporary Securities shall be exchangeable for definitive Securities upon
     surrender of the temporary Securities at the office or agency of the
     Company designated for such purpose pursuant to Section 4.02, without
     charge to the Holder.  Upon surrender for cancellation of any one or more
     temporary Securities the Company shall execute and the Trustee shall
     authenticate and deliver in exchange therefor a like principal amount at
     maturity of definitive Securities of authorized denominations.  Until so
     exchanged, the temporary Securities shall be entitled to the same benefits
     under this Indenture as definitive Securities.

               SECTION 2.12.  Cancellation.  The Company at any time may deliver
                            ------------
     to the Trustee for cancellation any Securities previously authenticated and
     delivered hereunder which the Company may have acquired in any manner
     whatsoever, and may deliver to the Trustee for cancellation any Securities
     previously authenticated hereunder which the Company has not issued and
     sold.  The Registrar and the Paying Agent shall forward to the Trustee any
     Securities surrendered to them for transfer, exchange or payment.  The
     Trustee shall cancel all Securities surrendered for transfer, exchange,
     payment or cancellation and shall destroy them in accordance with its
     normal procedure.  The Company shall not issue new Securities to replace
     Securities it has paid in full or delivered to the Trustee for
     cancellation.

               SECTION 2.13.  CUSIP Numbers.  The Company in issuing the 
                            -------------
     Securities may use "CUSIP" and "CINS" numbers (if then generally in use),
     and the Trustee shall use CUSIP numbers or CINS numbers, as the case may
     be, in notices of redemption or exchange as a convenience to Holders;
     provided that any such notice shall state that no representation is made as
     to the correctness of such numbers either as printed on the Securities or
     as contained in any notice of redemption or exchange and that reliance may
     be placed only on the other identification numbers printed on the
     Securities.

               SECTION 2.14.  Defaulted Interest.  If the Company defaults in a
                            ------------------
     payment of interest on the Securities, it shall pay, or shall deposit with
     the Paying Agent money in immediately available funds sufficient to pay the
     defaulted interest, plus (to the extent lawful)  interest on the defaulted
     interest, to the Persons who are Holders on a subsequent special record
     date.  A special record date, as used in this Section 2.14 with respect to
     the payment of any defaulted interest, shall mean the 15th day next
     preceding the date fixed by the Company for the payment of defaulted
     interest, whether or not such day is a Business Day.  At least 15 days
     before the subsequent special record date, the Company shall mail to each
     Holder and to the Trustee a notice that states the subsequent special
     record date, the payment date and the amount of defaulted interest to be
     paid.


                                    ARTICLE THREE
                                      REDEMPTION

               SECTION 3.01.  Right of Redemption.  (a)  The Securities may be 
                            -------------------
     redeemed at the election of the Company, in whole or in part, at any time
     and from time to time on or after March 15, 2002 and prior to maturity,
     upon not less than 30 nor more than 60 days' prior notice mailed by first-
     class mail to each Holder's last address as it appears in the Security
     Register, at the following Redemption Prices (expressed in percentages of
     their principal amount at maturity), plus accrued and unpaid interest, if
     any, to the Redemption Date (subject to the right of Holders of record on
     the relevant Regular Record Date that is on or prior to the Redemption Date
     to receive interest due on an Interest Payment Date that is on or prior to
     the Redemption Date) if redeemed during the 12-month period commencing on
     March 15 of the applicable year set forth below:

                                             Redemption
                    Year                         Price    
                    ----                     -------------
                    2002                     105.81250% 
                    2003                     102.90625
                    2004 and thereafter      100.00000

               (b)  In addition, at any time on or prior to March 15, 2000, the
     Company may, at its option from time to time, redeem Securities having an
     aggregate principal amount of up to 35% of the aggregate principal amount
     of all issued Securities, at a redemption price equal to 111 5/8% of the
     Accreted Value thereof on the Redemption Date, with proceeds of one or more
     Public Equity Offerings of Common Stock of (A) the Guarantor or (B) the
     Company, provided that (i) with respect to a Public Equity Offering
     referred to in clause (A) above, cash proceeds of such Public Equity
     Offering in an amount sufficient to effect the redemption of Securities to
     be so redeemed are contributed by the Guarantor to the Company prior to
     such redemption and used by the Company to effect such redemption and
     (ii) such redemption occurs within 180 days after consummation of such
     Public Equity Offering.

               SECTION 3.02.  Notices to Trustee.  If the Company elects to 
                            ------------------
     redeem Securities pursuant to Section 3.01, it shall notify the Trustee in
     writing of the Redemption Date and the principal amount at maturity of
     Securities to be redeemed.

               The Company shall give each notice provided for in this Section
     3.02 in an Officers' Certificate at least 60 days before the Redemption
     Date (unless a shorter period shall be satisfactory to the Trustee).

               SECTION 3.03.  Selection of Securities to Be Redeemed.  If less 
                            --------------------------------------
     than all of the Securities are to be redeemed at any time, the Trustee
     shall select the Securities to be redeemed in compliance with the
     requirements, as certified to it by the Company, of the principal national
     securities exchange, if any, on which the Securities are listed or, if the
     Securities are not listed on a national securities exchange, on a pro rata
     basis or by lot; provided that no Securities of $1,000 in principal amount
     at maturity or less shall be redeemed in part.

               The Trustee shall make the selection from the Securities
     outstanding and not previously called for redemption.  Securities in
     denominations of $1,000 in principal amount at maturity may only be
     redeemed in whole.  The Trustee may select for redemption portions (equal
     to $1,000 in principal amount at maturity or any integral multiple thereof)
     of Securities that have denominations larger than $1,000 in principal
     amount at maturity.  Provisions of this Indenture that apply to Securities
     called for redemption also apply to portions of Securities called for
     redemption.  The Trustee shall notify the Company and the Registrar
     promptly in writing of the Securities or portions of Securities to be
     called for redemption.

               SECTION 3.04.  Notice of Redemption.  With respect to any
                            --------------------
     redemption of Securities pursuant to Section 3.01, at least 30 days but not
     more than 60 days before a Redemption Date, the Company shall mail a notice
     of redemption by first class mail to each Holder whose Securities are to be
     redeemed.

               The notice shall identify the Securities to be redeemed and shall
     state:

               (i)  the Redemption Date;

               (ii) the Redemption Price;

               (iii)     the name and address of the Paying Agent;

               (iv) that Securities called for redemption must be surrendered to
          the Paying Agent in order to collect the Redemption Price;

               (v)  that, unless the Company defaults in making the redemption
          payment, interest on Securities called for redemption ceases to accrue
          on and after the Redemption Date and the only remaining right of the
          Holders is to receive payment of the Redemption Price plus accrued
          interest to the Redemption Date upon surrender of the Securities to
          the Paying Agent;

               (vi) that, if any Security is being redeemed in part, the portion
          of the principal amount at maturity (equal to $1,000 in principal
          amount at maturity or any integral multiple thereof) of such Security
          to be redeemed and that, on and after the Redemption Date, upon
          surrender of such Security, a new Security or Securities in principal
          amount at maturity equal to the unredeemed portion thereof will be
          reissued; and

               (vii)     that, if any Security contains a CUSIP number as
          provided in Section 2.13, no representation is being made as to the
          correctness of the CUSIP number either as printed on the Securities or
          as contained in the notice of redemption and that reliance may be
          placed only on the other identification numbers printed on the
          Securities.

               At the Company's request (which request may be revoked by the
     Company at any time prior to the time at which the Trustee shall have given
     such notice to the Holders), made in writing to the Trustee at least
     60 days (or such shorter period as shall be satisfactory to the Trustee)
     before a Redemption Date, the Trustee shall give the notice of redemption
     in the name and at the expense of the Company.  If, however, the Company
     gives such notice to the Holders, the Company shall concurrently deliver to
     the Trustee an Officers' Certificate stating that such notice has been
     given.

               SECTION 3.05.  Effect of Notice of Redemption.  Once notice of 
                            ------------------------------
     redemption is mailed, Securities called for redemption become due and
     payable on the Redemption Date and at the Redemption Price.  Upon surrender
     of any Securities to the Paying Agent, such Securities shall be paid at the
     Redemption Price, plus accrued interest, if any, to the Redemption Date.  

               Notice of redemption shall be deemed to be given when mailed,
     whether or not the Holder receives the notice.  In any event, failure to
     give such notice, or any defect therein, shall not affect the validity of
     the proceedings for the redemption of Securities held by Holders to whom
     such notice was properly given.

               SECTION 3.06.  Deposit of Redemption Price.  On or prior to any 
                            ---------------------------
     Redemption Date, the Company shall deposit with the Paying Agent (or, if
     the Company is acting as its own Paying Agent, shall segregate and hold in
     trust as provided in Section 2.05) money sufficient to pay the Redemption
     Price of and accrued interest on all Securities to be redeemed on that date
     other than Securities or portions thereof called for redemption on that
     date that have been delivered by the Company to the Trustee for
     cancellation.

               SECTION 3.07.  Payment of Securities Called for Redemption.  If 
                              -------------------------------------------
     notice of redemption has been given in the manner provided above, the
     Securities or portion of Securities specified in such notice to be redeemed
     shall become due and payable on the Redemption Date at the Redemption Price
     stated therein, together with accrued interest to such Redemption Date, and
     on and after such date (unless the Company shall default in the payment of
     such Securities at the Redemption Price and accrued interest to the
     Redemption Date, in which case the principal, until paid, shall bear
     interest from the Redemption Date at the rate prescribed in the
     Securities), such Securities shall cease to accrue interest.  Upon
     surrender of any Security for redemption in accordance with a notice of
     redemption, such Security shall be paid and redeemed by the Company at the
     Redemption Price, together with accrued interest, if any, to the Redemption
     Date; provided that installments of interest whose Stated Maturity is on or
     prior to the Redemption Date shall be payable to the Holders registered as
     such at the close of business on the relevant Regular Record Date.

               SECTION 3.08.  Securities Redeemed in Part.  Upon surrender of
                            ---------------------------
     any Security that is redeemed in part, the Company shall execute and the
     Trustee shall authenticate and deliver to the Holder a new Security equal
     in principal amount at maturity to the unredeemed portion of such
     surrendered Security.


                                     ARTICLE FOUR
                                      COVENANTS

               SECTION 4.01.  Payment of Securities.  The Company shall pay the 
                            ---------------------
     principal of, premium, if any, and interest on the Securities on the dates
     and in the manner provided in the Securities and this Indenture.  An
     installment of principal, premium, if any, or interest shall be considered
     paid on the date due if the Trustee or Paying Agent (other than the
     Company, a Subsidiary of the Company, or any Affiliate of any of them)
     holds on that date money designated for and sufficient to pay the
     installment.  If the Company or any Subsidiary of the Company or any
     Affiliate of any of them, acts as Paying Agent, an installment of
     principal, premium, if any, or interest shall be considered paid on the due
     date if the entity acting as Paying Agent complies with the last sentence
     of Section 2.05.  As provided in Section 6.09, upon any bankruptcy or
     reorganization procedure relative to the Company, the Trustee shall serve
     as the Paying Agent and conversion agent, if any, for the Securities.

               The Company shall pay interest on overdue principal, premium, if
     any, and interest on overdue installments of interest, to the extent
     lawful, at the rate per annum specified in the Securities.

               SECTION 4.02.  Maintenance of Office or Agency.  The Company will
                            -------------------------------
     maintain in the Borough of Manhattan, the City of New York an office or
     agency where Securities may be surrendered for registration of transfer or
     exchange or for presentation for payment and where notices and demands to
     or upon the Company in respect of the Securities and this Indenture may be
     served.  The Company will give prompt written notice to the Trustee of the
     location, and any change in the location, of such office or agency.  If at
     any time the Company shall fail to maintain any such required office or
     agency or shall fail to furnish the Trustee with the address thereof, such
     presentations, surrenders, notices and demands may be made or served at the
     address of the Trustee set forth in Section 11.02.

               The Company may also from time to time designate one or more
     other offices or agencies where the Securities may be presented or
     surrendered for any or all such purposes and may from time to time rescind
     such designations; provided that no such designation or rescission shall in
     any manner relieve the Company of its obligation to maintain an office or
     agency in the Borough of Manhattan, the City of New York for such purposes.
     The Company will give prompt written notice to the Trustee of any such
     designation or rescission and of any change in the location of any such
     other office or agency.

               The Company hereby initially designates the Corporate Trust
     Office of the Trustee, located in the Borough of Manhattan, the City of New
     York, as such office of the Company in accordance with Section 2.04.

               SECTION 4.03.  Limitation on Indebtedness.  (a)  The Guarantor 
                            --------------------------
     will not, and will not permit any of its Restricted Subsidiaries to, Incur
     any Indebtedness (other than the Securities, the Guarantor's Guarantee
     thereof and Indebtedness existing on the Closing Date); provided that the
     Guarantor and the Company may Incur Indebtedness if, after giving effect to
     the Incurrence of such Indebtedness and the receipt and application of the
     proceeds therefrom, the Indebtedness to EBITDA Ratio would be greater than
     zero and less than 5:1.

               Notwithstanding the foregoing, the Guarantor and any Restricted
     Subsidiary (except as specified below) may Incur each and all of the
     following:

               (i)  Indebtedness of the Guarantor or the Company outstanding at
          any time, which Indebtedness generates gross proceeds to the Guarantor
          or the Company of up to $400 million, less the gross proceeds of
          Indebtedness permanently repaid as provided under Section 4.11;
          provided that (A) Indebtedness generating gross proceeds to the
          Guarantor or the Company of up to $150 million may be Incurred under
          this clause (i) with no additional requirements and (B) prior to, or
          contemporaneously with, the Incurrence of Indebtedness generating all
          or any part of the remaining $250 million of gross proceeds referred
          to under this clause (i), the Guarantor or the Company shall have
          issued or shall issue preferred stock (which has a final stated
          redemption date later than the Stated Maturity of the 13 1/2% Notes)
          generating an amount of gross proceeds equal to or greater than the
          amount of Indebtedness so Incurred and (x) with respect to preferred
          stock issued on the same date as Indebtedness Incurred under this
          clause (a)(i)(B), having a dividend rate of no more than 2.75
          percentage points higher than the interest rate on the Indebtedness so
          Incurred, and (y) with respect to preferred stock issued at any other
          time which will be applied to satisfy the criteria under this clause
          (a)(i)(B), having a secondary market yield, on the same date as the
          Indebtedness so Incurred, which a nationally recognized investment
          banking firm certifies to the Trustee is no more than 2.75 percentage
          points higher than the interest rate on the Indebtedness that is being
          Incurred pursuant to this clause (a)(i)(B);

               (ii) Indebtedness to the Guarantor or any of its Wholly Owned
          Restricted Subsidiaries; provided that any subsequent issuance or
          transfer of any Capital Stock which results in any such Wholly Owned
          Restricted Subsidiary ceasing to be a Wholly Owned Restricted
          Subsidiary or any subsequent transfer of such Indebtedness (other than
          to the Guarantor or another Wholly Owned Restricted Subsidiary) shall
          be deemed, in each case, to constitute an Incurrence of such
          Indebtedness not permitted by this clause (ii);

               (iii)     Indebtedness issued in exchange for, or the net
          proceeds of which are used to refinance or refund, then outstanding
          Indebtedness, other than Indebtedness Incurred under clause (i), (ii),
          (v), (vi), (viii), (ix), (xi) or (xii) of this paragraph, and any
          refinancings thereof in an amount not to exceed the amount so
          refinanced or refunded (plus premiums, accrued interest, fees and
          expenses); provided that Indebtedness the proceeds of which are used
          to refinance or refund the Securities or Indebtedness that is pari
          passu with, or subordinated in right of payment to, the Securities or
          the Security Guarantee shall only be permitted under this clause (iii)
          if (A) in case the Securities are refinanced in part or the
          Indebtedness to be refinanced is pari passu with the Securities or the
          Security Guarantee, as the case may be, such new Indebtedness, by its
          terms or by the terms of any agreement or instrument pursuant to which
          such new Indebtedness is outstanding, is expressly made pari passu
          with, or subordinate in right of payment to, the remaining Securities
          or the Security Guarantee, as the case may be, (B) in case the
          Indebtedness to be refinanced is subordinated in right of payment to
          the Securities or the Security Guarantee, as the case may be, such new
          Indebtedness, by its terms or by the terms of any agreement or
          instrument pursuant to which such new Indebtedness is issued or
          remains outstanding, is expressly made subordinate in right of payment
          to the Securities or the Security Guarantee, as the case may be, at
          least to the extent that the Indebtedness to be refinanced is
          subordinated to the Securities or the Security Guarantee, as the case
          may be and (C) such new Indebtedness, determined as of the date of
          Incurrence of such new Indebtedness, does not mature prior to the
          Stated Maturity of the Indebtedness to be refinanced or refunded, and
          the Average Life of such new Indebtedness is at least equal to the
          remaining Average Life of the Indebtedness to be refinanced or
          refunded; and provided further that in no event may Indebtedness of
          the Guarantor or the Company be refinanced by means of any
          Indebtedness of any Restricted Subsidiary of the Guarantor or the
          Company, as the case may be, pursuant to this clause (iii);

               (iv) Indebtedness (A) in respect of performance, surety or appeal
          bonds provided in the ordinary course of business, (B) under Currency
          Agreements and Interest Rate Agreements; provided that such agreements
          do not increase the Indebtedness of the obligor outstanding at any
          time other than as a result of fluctuations in foreign currency
          exchange rates or interest rates or by reason of fees, indemnities and
          compensation payable thereunder, and (C) arising from agreements
          providing for indemnification, adjustment of purchase price or similar
          obligations, or from Guarantees or letters of credit, surety bonds or
          performance bonds securing any obligations of the Company or any of
          its Restricted Subsidiaries pursuant to such agreements, in any case
          Incurred in connection with the disposition of any business, assets or
          Restricted Subsidiary of the Company (other than Guarantees of
          Indebtedness Incurred by any Person acquiring all or any portion of
          such business, assets or Restricted Subsidiary of the Company for the
          purpose of financing such acquisition), in a principal amount at
          maturity not to exceed the gross proceeds actually received by the
          Company or any Restricted Subsidiary in connection with such
          disposition; 

               (v)  Indebtedness of the Guarantor or, to the extent the proceeds
          referred to below are contributed to the Company, the Company not to
          exceed, at any one time outstanding, twice the amount of Net Cash
          Proceeds received by the Guarantor after the Closing Date from the
          issuance and sale of its Capital Stock (other than Redeemable Stock);
          provided that such Indebtedness does not mature prior to the Stated
          Maturity of the Securities and has an Average Life longer than the
          Securities;

               (vi) Strategic Investor Subordinated Indebtedness; 

               (vii)     Indebtedness of the Guarantor or the Company, to the
          extent the proceeds thereof are immediately used after the Incurrence
          thereof to purchase Securities, 13 1/2% Notes and/or 12 1/2% Notes
          tendered in an Offer to Purchase or an offer to purchase, as the case
          may be, made as a result of a Change of Control or a change of
          control, as the case may be; 

               (viii)    Indebtedness of any Restricted Subsidiary of the
          Guarantor Incurred pursuant to any credit agreement (including
          equipment leasing or financing agreements) of such Restricted
          Subsidiary in effect on August 8, 1995 (or any agreement refinancing
          Indebtedness under such credit agreement), up to the amount of the
          commitment under such credit agreement on August 8, 1995; 

               (ix) Indebtedness of the Guarantor or the Company, in an amount
          not to exceed $100 million at any one time outstanding, consisting of
          Capitalized Lease Obligations with respect to assets that are used or
          useful in the telecommunications business of the Guarantor or its
          Restricted Subsidiaries; 

               (x)  Indebtedness Incurred to defease the Securities; 

               (xi) Indebtedness of any Person that becomes a Restricted
          Subsidiary of the Guarantor after March 31, 1996, which Indebtedness
          exists or for which there is a commitment to lend at the time such
          Person becomes a Restricted Subsidiary and subsequent Incurrences
          thereof ("Acquired Indebtedness"), in an accreted amount not to exceed
                  ---------------------
          $50 million at any one time outstanding in the aggregate for all such
          Restricted Subsidiaries; provided that such Acquired Indebtedness does
          not exceed 65% of the consideration (calculated by including the
          Acquired Indebtedness as a part of such consideration) for the
          acquisition of such Person; 

               (xii)     Indebtedness of the Guarantor or the Company, in an
          amount not to exceed $30 million at any one time outstanding,
          consisting of letters of credit and similar arrangements used to
          support obligations of the Guarantor or any of its Restricted
          Subsidiaries with respect to the acquisition of (by purchase, lease or
          otherwise), construction of, or improvements on, assets that will be
          used or useful in the telecommunications business of the Guarantor or
          its Restricted Subsidiaries; and 

               (xiii)    Indebtedness Incurred to finance the cost (including
          the cost of design, development, construction, installation or
          integration) of assets, equipment or inventory used or useful in the
          telecommunications business of the Guarantor or any of its Restricted
          Subsidiaries that is acquired by the Guarantor or any of its
          Restricted Subsidiaries after the Closing Date. 

               (b)  For purposes of determining any particular amount of
     Indebtedness under this Section 4.03, (1) Indebtedness of any Restricted
     Subsidiary of the Guarantor Incurred on or prior to the Closing Date
     pursuant to any credit agreement (including equipment leasing or financing
     agreements) of such Restricted Subsidiary in effect on the Closing Date
     shall be treated as Incurred pursuant to Section 4.03(a)(viii), (2) any
     Liens granted pursuant to the equal and ratable provisions referred to in
     the first paragraph of Section 4.09 shall not be treated as Indebtedness
     and (3) Guarantees, Liens or obligations with respect to letters of credit
     supporting Indebtedness otherwise included in the determination of such
     particular amount shall not be included.  For purposes of determining
     compliance with this Section 4.03, in the event that an item of
     Indebtedness meets the criteria of more than one of the types of
     Indebtedness described in clauses (i) through (xiii) of Section 4.03(a),
     the Company, in its sole discretion, shall classify such item of
     Indebtedness and only be required to include the amount and type of such
     Indebtedness in one of such clauses.

               Notwithstanding any other provision of this Section 4.03, (i) the
     maximum amount of Indebtedness that the Guarantor or any Restricted
     Subsidiary may Incur pursuant to this Section 4.03 shall not be deemed to
     be exceeded due solely to fluctuations in the exchange rates of currencies
     and (ii) the Guarantor and the Company may not Incur any Indebtedness that
     is expressly subordinated to any other Indebtedness of the Guarantor or the
     Company, as the case may be, unless such Indebtedness, by its terms or the
     terms of any agreement or instrument pursuant to which such Indebtedness is
     outstanding, is also expressly made subordinate to the Security Guarantee
     or the Securities, as the case may be, at least to the extent that such
     Indebtedness is subordinated to such other Indebtedness; provided that the
     limitation in this clause (ii) shall not apply to distinctions between
     categories of unsubordinated Indebtedness which exist by reason of (a) any
     liens or other encumbrances arising or created in respect of some but not
     all unsubordinated Indebtedness, (b) intercreditor agreements between
     holders of different classes of unsubordinated Indebtedness or (c)
     different maturities or prepayment provisions.

               SECTION 4.04.  Limitation on Restricted Payments.  So long as any
                            ---------------------------------
     of the Securities are outstanding, the Guarantor will not, and will not
     permit any Restricted Subsidiary to, directly or indirectly, (i) declare or
     pay any dividend or make any distribution on its Capital Stock held by
     Persons other than the Guarantor or any of its Restricted Subsidiaries
     (other than dividends or distributions payable solely in shares of its or
     such Restricted Subsidiary's Capital Stock (other than Redeemable Stock) of
     the same class held by such holders or in options, warrants or other rights
     to acquire such shares of Capital Stock and other than pro rata dividends
     or distributions on Common Stock of Restricted Subsidiaries), (ii)
     purchase, redeem, retire or otherwise acquire for value any shares of
     Capital Stock of the Guarantor or any Restricted Subsidiary (including
     options, warrants or other rights to acquire such shares of Capital Stock)
     held by Persons other than the Guarantor or any of its Wholly Owned
     Restricted Subsidiaries (except for Capital Stock of ChoiceCom, MTN,
     StarCom, Ohio LINX, FOTI and Zycom to the extent the consideration therefor
     consists solely of Common Stock (other than Redeemable Stock) of the
     Guarantor transferred in compliance with the Securities Act), (iii) make
     any voluntary or optional principal payment, or voluntary or optional
     redemption, repurchase, defeasance or other acquisition or retirement for
     value, of Indebtedness of the Company or the Guarantor that is subordinated
     in right of payment to the Securities or the Security Guarantee, as the
     case may be, or (iv) make any Investment, other than a Permitted
     Investment, in any Person (such payments or any other actions described in
     clauses (i) through (iv) being collectively "Restricted Payments") if, at
                                                  -------------------
     the time of, and after giving effect to, the proposed Restricted Payment:
     (A) a Default or Event of Default shall have occurred and be continuing,
     (B) the Guarantor could not Incur at least $1.00 of Indebtedness under the
     first paragraph of Section 4.03(a) or (C) the aggregate amount expended for
     all Restricted Payments (the amount so expended, if other than in cash, to
     be determined in good faith by the Board of Directors, whose determination
     shall be conclusive and evidenced by a Board Resolution) after the date of
     this Indenture shall exceed the sum of (1) 50% of the aggregate amount of
     the Adjusted Consolidated Net Income (or, if the Adjusted Consolidated Net
     Income is a loss, minus 100% of such amount) (determined by excluding
     income resulting from transfers of assets by the Guarantor or a Restricted
     Subsidiary to an Unrestricted Subsidiary) accrued on a cumulative basis
     during the period (taken as one accounting period) beginning on the first
     day of the fiscal quarter immediately following the Closing Date and ending
     on the last day of the last fiscal quarter preceding the Transaction Date
     for which reports have been filed pursuant to Section 4.18 plus (2) the
     aggregate Net Cash Proceeds received by the Guarantor after the Closing
     Date from the issuance and sale permitted by this Indenture of its Capital
     Stock (other than Redeemable Stock) to a Person who is not a Subsidiary of
     the Guarantor, or from the issuance to a Person who is not a Subsidiary of
     the Guarantor of any options, warrants or other rights to acquire Capital
     Stock of the Guarantor (in each case, exclusive of any Redeemable Stock or
     any options, warrants or other rights that are redeemable at the option of
     the holder, or are required to be redeemed, prior to the Stated Maturity of
     the Securities) plus (3) an amount equal to the net reduction in
     Investments (other than reductions in Permitted Investments) in any Person
     resulting from payments of interest on Indebtedness, dividends, repayments
     of loans or advances, or other transfers of assets, in each case to the
     Guarantor or any Restricted Subsidiary (except to the extent any such
     payment is included in the calculation of Adjusted Consolidated Net
     Income), or from redesignations of Unrestricted Subsidiaries as Restricted
     Subsidiaries (valued in each case as provided in the definition of
     "Investments"), not to exceed the amount of Investments previously made by
     the Guarantor and its Restricted Subsidiaries in such Person. 

               The foregoing provision shall not be violated by reason of: 

               (i)  the payment of any dividend within 60 days after the date of
          declaration thereof if, at said date of declaration, such payment
          would comply with the foregoing paragraph; 

               (ii) the redemption, repurchase, defeasance or other acquisition
          or retirement for value of Indebtedness that is subordinated in right
          of payment to the Securities or the Security Guarantee, as the case
          may be, including premium, if any, and accrued and unpaid interest,
          with the proceeds of, or in exchange for, Indebtedness Incurred under
          clause (iii) of the second paragraph of Section 4.03(a); 

               (iii)     the repurchase, redemption or other acquisition of
          Capital Stock of the Guarantor or the Company (or options, warrants or
          other rights to acquire such Capital Stock) and with respect to any
          preferred stock of the Company, the payment of accrued dividends
          thereon in exchange for, or out of the proceeds of a substantially
          concurrent issuance or sale of, shares of Capital Stock (other than
          Redeemable Stock) of the Guarantor or the Company; provided that the
          redemption of any preferred stock and the payment of accrued dividends
          thereon pursuant to any mandatory redemption feature thereof and any
          redemption of any other Capital Stock and with respect to any
          preferred stock, the payment of accrued dividends thereon (or options,
          warrants or other rights to acquire such Capital Stock) shall be
          deemed to be "substantially concurrent" with such issuance and sale if
          the required notice with respect to such redemption is irrevocably
          given by a date which is no later than five Business Days after
          receipt of the proceeds of such issuance and sale and such redemption
          and payment is consummated within the period provided for in the
          documents providing for the redemption of such preferred stock or the
          documents governing the redemption of such other Capital Stock, as the
          case may be; 

               (iv) the acquisition of Indebtedness of the Company or the
          Guarantor which is subordinated in right of payment to the Securities
          or the Security Guarantee, as the case may be, in exchange for, or out
          of the proceeds of, a substantially concurrent offering of, shares of
          the Capital Stock of the Guarantor (other than Redeemable Stock); 

               (v)  payments or distributions, in the nature of satisfaction of
          dissenters' rights, pursuant to or in connection with a consolidation,
          merger or transfer of assets that complies with the provisions of this
          Indenture applicable to mergers, consolidations and transfers of all
          or substantially all of the property and assets of the Company or the
          Guarantor; 

               (vi) Investments, not to exceed $10 million in the aggregate,
          each evidenced by a senior promissory note payable to the Company that
          provides that it will become due and payable prior to (or, in the case
          of acceleration, concurrently with) any required repayment (including
          pursuant to an Offer to Purchase in connection with a Change of
          Control) of the Securities; 

               (vii)     Investments, not to exceed $5 million in the aggregate,
          that meet the requirements of clause (vi) of this Section 4.04;
          provided that the Board of Directors of the Guarantor shall have
          determined, in good faith, that each such Investment under this clause
          (vii) will enable the Guarantor, the Company or one of their
          Restricted Subsidiaries to obtain additional business that it might
          not be able to obtain without the making of such Investment; 

               (viii)    with respect to preferred stock permitted to be issued
          and sold under Section 4.06 of this Indenture, the payment (A) of
          dividends on such preferred stock in additional shares of preferred
          stock and (B) of cash dividends on such preferred stock and accrued
          interest on unpaid dividends, in each case after May 1, 2001; 

               (ix) the repurchase, in the event of a Change of Control, of
          preferred stock of the Company or the Guarantor and Indebtedness of
          the Company or the Guarantor into which such preferred stock has been
          exchanged; provided that prior to repurchasing such preferred stock or
          Indebtedness, the Company or the Guarantor, as the case may be, shall
          have made an offer (the "Change of Control Offer") to repurchase the
                                    -----------------------
          Securities in accordance with the terms of this Indenture (and an
          offer to repurchase other Indebtedness, if required by the terms
          thereof, in accordance with the indenture or other document governing
          such other Indebtedness) and shall have accepted and paid for any
          Securities (and other Indebtedness) properly tendered in connection
          with such Change of Control Offer for the Securities or change of
          control offer for such other Indebtedness; and

               (x)  the issuance of Indebtedness permitted to be issued under
          this Indenture in exchange for preferred stock; provided that the
          Incurrence of such Indebtedness complies with Section 4.03;

     provided that, except in the case of clauses (i) and (iii), no Default or
     Event of Default shall have occurred and be continuing or occur as a
     consequence of the actions or payments set forth therein. 

               Each Restricted Payment permitted pursuant to the preceding
     paragraph (other than the Restricted Payment referred to in clauses (ii),
     (viii)(A) and (x) thereof), and the Net Cash Proceeds from any issuance of
     Capital Stock referred to in clause (iii) or (iv) shall be included in
     calculating whether the conditions of clause (C) of the first paragraph of
     this Section 4.04 have been met with respect to any subsequent Restricted
     Payments.  Notwithstanding the foregoing, in the event the proceeds of an
     issuance of Capital Stock of the Guarantor are used for the redemption,
     repurchase or other acquisition of the Securities, or Indebtedness that is
     pari passu with the Securities, then the Net Cash Proceeds of such issuance
     shall be included in clause (C) of the first paragraph of this Section 4.04
     only to the extent such proceeds are not used for such redemption,
     repurchase or other acquisition of such Indebtedness. 

               SECTION 4.05.  Limitation on Dividend and Other Payment 
                            -----------------------------------------
     Restrictions Affecting Restricted Subsidiaries.  So long as any Securities 
     ----------------------------------------------
     are outstanding, the Guarantor will not, and will not permit any Restricted
     Subsidiary to, create or otherwise cause or suffer to exist or become
     effective any consensual encumbrance or restriction of any kind on the
     ability of any Restricted Subsidiary to (i) pay dividends or make any other
     distributions permitted by applicable law on any Capital Stock of such
     Restricted Subsidiary owned by the Guarantor or any other Restricted
     Subsidiary, (ii) pay any Indebtedness owed to the Guarantor or any other
     Restricted Subsidiary, (iii) make loans or advances to the Guarantor or any
     other Restricted Subsidiary or (iv) transfer any of its property or assets
     to the Guarantor or any other Restricted Subsidiary. 

               The foregoing provisions shall not restrict any encumbrances or
     restrictions: 

               (i)  existing on the Closing Date in this Indenture or any other
          agreement in effect on the Closing Date, and any extensions,
          refinancings, renewals or replacements of such agreements; provided
          that the encumbrances and restrictions in any such extensions,
          refinancings, renewals or replacements are no less favorable in any
          material respect to the Holders than those encumbrances or
          restrictions that are then in effect and that are being extended,
          refinanced, renewed or replaced; 

               (ii) existing under or by reason of applicable law; 

               (iii)     existing with respect to any Person or the property or
          assets of such Person acquired by the Guarantor or any Restricted
          Subsidiary, existing at the time of such acquisition and not incurred
          in contemplation thereof, which encumbrances or restrictions are not
          applicable to any Person or the property or assets of any Person other
          than such Person or the property or assets of such Person so acquired;

               (iv) in the case of clause (iv) of the first paragraph of this
          Section 4.05, (A) that restrict in a customary manner the subletting,
          assignment or transfer of any property or asset that is a lease,
          license, conveyance or contract or similar property or asset, (B)
          existing by virtue of any transfer of, agreement to transfer, option
          or right with respect to, or Lien on, any property or assets of the
          Guarantor or any Restricted Subsidiary not otherwise prohibited by
          this Indenture or (C) arising or agreed to in the ordinary course of
          business, not relating to any Indebtedness, and that do not,
          individually or in the aggregate, detract from the value of property
          or assets of the Guarantor or any Restricted Subsidiary in any manner
          material to the Guarantor or any Restricted Subsidiary; 

               (v)  with respect to a Restricted Subsidiary and imposed pursuant
          to an agreement that has been entered into for the sale or disposition
          of all or substantially all of the Capital Stock of, or property and
          assets of, such Restricted Subsidiary; or 

               (vi) imposed pursuant to preferred stock of the Company issued
          under clause (vi) of Section 4.06, or exchange debentures or exchange
          notes of the Company issued in exchange therefor; provided that
          (A) such restrictions may include a prohibition (x) on payments on
          Capital Stock upon liquidation, winding-up and dissolution of the
          Company and (y) on the payment of dividends on and the making of any
          distribution on, or the purchase, redemption, retirement or other
          acquisition for value of Capital Stock of the Company if dividends or
          other amounts on such preferred stock are unpaid and (B) any
          restrictions imposed pursuant to preferred stock of the Company other
          than pursuant to clause (A) shall be no more restrictive than the
          restrictions contained in this Indenture (assuming that references to
          the Guarantor in this Indenture were replaced with references to the
          Company). 

               Nothing contained in this Section 4.05 shall prevent the
     Guarantor or any Restricted Subsidiary from (1) creating, incurring,
     assuming or suffering to exist any Liens otherwise permitted in Section
     4.09 or (2) restricting the sale or other disposition of property or assets
     of the Guarantor or any of its Restricted Subsidiaries that secure
     Indebtedness of the Guarantor or any of its Restricted Subsidiaries. 

               SECTION 4.06.  Limitation on the Issuances and Sale of Capital
                            -----------------------------------------------
     Stock of Restricted Subsidiaries.  The Guarantor will not sell, and will 
     --------------------------------
     not permit any Restricted Subsidiary, directly or indirectly, to issue or
     sell, any shares of Capital Stock of a Restricted Subsidiary (including
     options, warrants or other rights to purchase shares of such Capital Stock)
     except (i) to the Guarantor or a Wholly Owned Restricted Subsidiary; (ii)
     issuances or sales to foreign nationals of shares of Capital Stock of
     foreign Restricted Subsidiaries, to the extent required by applicable law;
     (iii) if, immediately after giving effect to such issuance or sale, such
     Restricted Subsidiary would no longer constitute a Restricted Subsidiary;
     (iv) with respect to Common Stock of ChoiceCom, MTN, StarCom and Zycom;
     provided that the proceeds of any such sale under clause (iv) shall be
     applied in accordance with clause (A) or (B) of the first paragraph of
     Section 4.11; (v) with respect to Common Stock of FOTI; provided that FOTI
     shall not retain any net proceeds from such sales or issuances in excess of
     $10 million in the aggregate and any net proceeds in excess of such $10
     million shall be received by, or paid promptly by FOTI to, the Guarantor,
     the Company or any Wholly Owned Restricted Subsidiary of the Guarantor; and
     (vi) with respect to (A) preferred stock of the Company having an initial
     liquidation preference of up to $250 million and (B) any preferred stock of
     the Company issued as dividends on such preferred stock; provided that such
     preferred stock does not require the payment of cash dividends prior to May
     1, 2001. 

               SECTION 4.07.  Limitation on Issuances of Guarantees by 
                            -----------------------------------------
     Restricted Subsidiaries.  The Guarantor will not permit any Restricted 
     -----------------------
     Subsidiary, directly or indirectly, to Guarantee any Indebtedness of the
     Company or any Indebtedness of the Guarantor ("Guaranteed Indebtedness"), 
                                                    -----------------------
     unless (i) such Restricted Subsidiary simultaneously executes and delivers
     a supplemental indenture to this Indenture providing for a Guarantee (a
     "Subsidiary Guarantee") of payment of the Securities by such Restricted 
      --------------------
     Subsidiary and (ii) such Restricted Subsidiary waives and will not in any
     manner whatsoever claim or take the benefit or advantage of, any rights of
     reimbursement, indemnity or subrogation or any other rights against the
     Guarantor, the Company or any other Restricted Subsidiary as a result of
     any payment by such Restricted Subsidiary under its Subsidiary Guarantee;
     provided that this paragraph shall not be applicable to any Guarantee of
     any Restricted Subsidiary that (x) existed at the time such Person became a
     Restricted Subsidiary and (y) was not Incurred in connection with, or in
     contemplation of, such Person becoming a Restricted Subsidiary.  If the
     Guaranteed Indebtedness is (A) pari passu with the Securities or the
     Security Guarantee, then the Guarantee of such Guaranteed Indebtedness
     shall be pari passu with, or subordinated to, the Subsidiary Guarantee or
     (B) subordinated to the Securities or the Security Guarantee, then the
     Guarantee of such Guaranteed Indebtedness shall be subordinated to the
     Subsidiary Guarantee at least to the extent that the Guaranteed
     Indebtedness is subordinated to the Securities or the Security Guarantee,
     as the case may be. 

               Notwithstanding the foregoing, any Subsidiary Guarantee by a
     Restricted Subsidiary shall provide by its terms that it shall be
     automatically and unconditionally released and discharged upon (i) any
     sale, exchange or transfer, to any Person not an Affiliate of the Guarantor
     of all of the Company's and each Restricted Subsidiary's Capital Stock in,
     or all or substantially all the assets of, such Restricted Subsidiary
     (which sale, exchange or transfer is not prohibited by this Indenture) or
     (ii) the release or discharge of the Guarantee which resulted in the
     creation of such Subsidiary Guarantee, except a discharge or release by or
     as a result of payment under such Guarantee. 

               SECTION 4.08.  Limitation on Transactions with Shareholders and 
                            -------------------------------------------------
     Affiliates.  The Guarantor will not, and will not permit any Restricted 
     ----------
     Subsidiary to, directly or indirectly, enter into, renew or extend any
     transaction (including, without limitation, the purchase, sale, lease or
     exchange of property or assets, or the rendering of any service) with any
     holder (or any Affiliate of such holder) of 5% or more of any class of
     Capital Stock of the Guarantor or with any Affiliate of the Guarantor or
     any Restricted Subsidiary, except upon fair and reasonable terms no less
     favorable to the Guarantor or such Restricted Subsidiary than could be
     obtained, at the time of such transaction or at the time of the execution
     of the agreement providing therefor, in a comparable arm's-length
     transaction with a Person that is not such a holder or an Affiliate. 

               The foregoing limitation does not limit, and shall not apply to:

               (i)   transactions (A) approved by a majority of the
          disinterested members of the Board of Directors or (B) for which the
          Guarantor or a Restricted Subsidiary delivers to the Trustee a written
          opinion of a nationally recognized investment banking firm stating
          that the transaction is fair to the Guarantor or such Restricted
          Subsidiary from a financial point of view; 

               (ii) any transaction solely between the Guarantor and any of its
          Wholly Owned Restricted Subsidiaries or solely between Wholly Owned
          Restricted Subsidiaries; 

               (iii)     the payment of reasonable and customary regular fees to
          directors of the Guarantor, the Company or Holdings (Canada) who are
          not employees of the Guarantor, the Company or Holdings (Canada); 

               (iv) any payments or other transactions pursuant to any tax-
          sharing agreement between the Guarantor and any other Person with
          which the Guarantor files a consolidated tax return or with which the
          Guarantor is part of a consolidated group for tax purposes; or 

               (v)  any Restricted Payments not prohibited by Section 4.04. 

               Notwithstanding the foregoing, any transaction covered by the
     first paragraph of this Section 4.08 and not covered by clauses (ii)
     through (iv) of this paragraph, the aggregate amount of which exceeds $2
     million in value, must be approved or determined to be fair in the manner
     provided for in clause (i)(A) or (B) of this Section 4.08. 

               SECTION 4.09.  Limitation on Liens.  The Guarantor will not, and
                            -------------------
     will not permit any Restricted Subsidiary to, create, incur, assume or
     suffer to exist any Lien on any of its assets or properties of any
     character, or any shares of Capital Stock or Indebtedness of any Restricted
     Subsidiary, without making effective provision for all of the Securities
     (or, in the case of a Lien on assets or properties of the Guarantor, the
     Security Guarantee) and all other amounts due under this Indenture to be
     directly secured equally and ratably with (or, if the obligation or
     liability to be secured by such Lien is subordinated in right of payment to
     the Securities or the Security Guarantee, prior to) the obligation or
     liability secured by such Lien. 

               The foregoing limitation does not apply to:

               (i)  Liens existing on the Closing Date; 

               (ii) Liens granted after the Closing Date on any assets or
          Capital Stock of Holdings (Canada), the Company or any of their
          Restricted Subsidiaries created in favor of the Holders; 

               (iii)     Liens with respect to the assets of a Restricted
          Subsidiary granted by such Restricted Subsidiary to the Guarantor or a
          Wholly Owned Restricted Subsidiary to secure Indebtedness owing to the
          Guarantor or such other Restricted Subsidiary; 

               (iv) Liens securing Indebtedness which is Incurred to refinance
          secured Indebtedness which is permitted to be Incurred under clause
          (iii) of the second paragraph of Section 4.03(a); provided that such
          Liens do not extend to or cover any property or assets of the
          Guarantor, the Company or any Restricted Subsidiary other than the
          property or assets securing the Indebtedness being refinanced; 

               (v)  Liens with respect to assets or properties of any Person
          that becomes a Restricted Subsidiary after the Closing Date; provided
          that such Liens do not extend to or cover any assets or properties of
          the Guarantor or any of its Restricted Subsidiaries other than the
          assets or properties of such Person subject to such Lien on the date
          such Person becomes a Restricted Subsidiary; and provided further that
          such Liens are not incurred in contemplation of, or in connection
          with, such Person becoming a Restricted Subsidiary; 

               (vi) Permitted Liens; or 

               (vii)     Liens, solely in favor of Acquired Indebtedness, on
          Capital Stock of Persons that become Restricted Subsidiaries of the
          Guarantor after the Closing Date. 

               SECTION 4.10.  Limitation on Sale-Leaseback Transactions.  The 
                            -----------------------------------------
     Guarantor will not, and will not permit any Restricted Subsidiary to, enter
     into any sale-leaseback transaction involving any of its assets or
     properties whether now owned or hereafter acquired, whereby the Guarantor
     or a Restricted Subsidiary sells or transfers such assets or properties and
     then or thereafter leases such assets or properties or any part thereof or
     any other assets or properties which the Guarantor or such Restricted
     Subsidiary, as the case may be, intends to use for substantially the same
     purpose or purposes as the assets or properties sold or transferred. 

               The foregoing restriction does not apply to any sale-leaseback
     transaction if:

               (i)  the lease is for a period, including renewal rights, of not
          in excess of three years; 

               (ii) the lease secures or relates to industrial revenue or
          pollution control bonds; 

               (iii)     the transaction is between the Guarantor and any Wholly
          Owned Restricted Subsidiary or between Wholly Owned Restricted
          Subsidiaries; or 

               (iv) the Guarantor or such Restricted Subsidiary, within six
          months after the sale or transfer of any assets or properties is
          completed, applies an amount not less than the net proceeds received
          from such sale in accordance with clause (A) or (B) of the first
          paragraph of Section 4.11.
      
               SECTION 4.11.  Limitation on Asset Sales.  The Guarantor will 
                            -------------------------
     not, and will not permit any Restricted Subsidiary to, consummate any Asset
     Sale, unless (i) the consideration received by the Guarantor or such
     Restricted Subsidiary is at least equal to the fair market value of the
     assets sold or disposed of and (ii) at least 75% of the consideration
     received consists of cash or Temporary Cash Investments.  In the event and
     to the extent that the Net Cash Proceeds received by the Guarantor or its
     Restricted Subsidiaries from one or more Asset Sales occurring on or after
     the Closing Date in any period of 12 consecutive months exceed 10% of
     Adjusted Consolidated Net Tangible Assets (determined as of the date
     closest to the commencement of such 12-month period for which a
     consolidated balance sheet of the Company and its Subsidiaries has been
     prepared), then the Guarantor shall or shall cause the relevant Restricted
     Subsidiary to (i) within six months after the date Net Cash Proceeds so
     received exceed 10% of Adjusted Consolidated Net Tangible Assets (A) apply
     an amount equal to such excess Net Cash Proceeds to permanently repay
     unsubordinated Indebtedness of the Guarantor or the Company, or
     Indebtedness of any Restricted Subsidiary other than the Company, in each
     case owing to a Person other than the Guarantor or any of its Restricted
     Subsidiaries or (B) invest an equal amount, or the amount not so applied
     pursuant to clause (A) (or enter into a definitive agreement committing to
     so invest within six months after the date of such agreement), in property
     or assets of a nature or type or that are used in a business (or in a
     company having property and assets of a nature or type, or engaged in a
     business) similar or related to the nature or type of the property and
     assets of, or the business of, the Guarantor and its Restricted
     Subsidiaries existing on the date of such investment (as determined in good
     faith by the Board of Directors, whose determination shall be conclusive
     and evidenced by a Board Resolution) and (ii) apply (no later than the end
     of the six-month period referred to in clause (i)) such excess Net Cash
     Proceeds (to the extent not applied pursuant to clause (i)) as provided in
     the following paragraphs of this Section 4.11.  The amount of such excess
     Net Cash Proceeds required to be applied (or to be committed to be applied)
     during such six-month period as set forth in clause (i) of the preceding
     sentence and not applied as so required by the end of such period shall
     constitute "Excess Proceeds." 
                ---------------

               If, as of the first day of any calendar month, the aggregate
     amount of Excess Proceeds not theretofore subject to an Offer to Purchase
     pursuant to this Section 4.11 totals at least $10 million, the Company must
     commence, not later than the fifteenth Business Day of such month, and
     consummate an Offer to Purchase from the Holders on a pro rata basis an
     aggregate Accreted Value of Securities equal to the Excess Proceeds on such
     date, at a purchase price equal to 101% of the Accreted Value of the
     Securities, plus, in each case, accrued interest (if any) to the date of
     purchase. 

               SECTION 4.12.  Repurchase of Securities upon a Change of Control.
                              -------------------------------------------------
     The Company must commence, within 30 days of the occurrence of a Change of
     Control, and consummate an Offer to Purchase for all Securities then
     outstanding, at a purchase price equal to 101% of the Accreted Value
     thereof, plus accrued interest (if any) to the date of purchase. Prior to
     the mailing of the notice to Holders commencing such Offer to Purchase, but
     in any event within 30 days following any Change of Control, the Company
     covenants to (i) repay in full all indebtedness of the Company that would
     prohibit the repurchase of the Securities pursuant to such Offer to
     Purchase or (ii) obtain any requisite consents under instruments governing
     any such indebtedness of the Company to permit the repurchase of the
     Securities.  The Company shall first comply with the covenant in the
     preceding sentence before it shall be required to repurchase the Securities
     pursuant to this Section 4.12.

               SECTION 4.13.  Existence.  Subject to Articles Four and Five of 
                            ---------
     this Indenture, the Guarantor will do or cause to be done all things
     necessary to preserve and keep in full force and effect its existence and
     the existence of each of its Restricted Subsidiaries in accordance with the
     respective organizational documents of the Guarantor and each such
     Subsidiary and the rights (whether pursuant to charter, partnership
     certificate, agreement, statute or otherwise), material licenses and
     franchises of the Guarantor and each such Subsidiary; provided that the
     Guarantor shall not be required to preserve any such right, license or
     franchise, or the existence of any Restricted Subsidiary (other than itself
     and the Company), if the maintenance or preservation thereof is no longer
     desirable in the conduct of the business of the Guarantor and its
     Restricted Subsidiaries taken as a whole.  In addition, the Guarantor
     agrees to take such actions, within a reasonable time after the Closing
     Date (and in any event prior to any proceeding initiated regarding the
     dissolution of the Guarantor), as may be necessary to ensure that it shall
     be in good standing under the laws of the jurisdiction of its
     incorporation.

               SECTION 4.14.  Payment of Taxes and Other Claims.  The Guarantor
                            ---------------------------------
     will pay or discharge and shall cause each of its Subsidiaries to pay or
     discharge, or cause to be paid or discharged, before the same shall become
     delinquent (i) all material taxes, assessments and governmental charges
     levied or imposed upon (a) the Guarantor or any such Subsidiary, (b) the
     income or profits of any such Subsidiary which is a corporation or (c) the
     property of the Guarantor or any such Subsidiary and (ii) all material
     lawful claims for labor, materials and supplies that, if unpaid, might by
     law become a lien upon the property of the Guarantor or any such
     Subsidiary; provided that the Guarantor shall not be required to pay or
     discharge, or cause to be paid or discharged, any such tax, assessment,
     charge or claim the amount, applicability or validity of which is being
     contested in good faith by appropriate proceedings and for which adequate
     reserves have been established.

               SECTION 4.15.  Maintenance of Properties and Insurance.  The 
                            ---------------------------------------
     Guarantor will cause all properties used or useful in the conduct of its
     business or the business of any of its Restricted Subsidiaries, to be
     maintained and kept in good condition, repair and working order and
     supplied with all necessary equipment and will cause to be made all
     necessary repairs, renewals, replacements, betterments and improvements
     thereof, all as in the judgment of the Guarantor may be necessary so that
     the business carried on in connection therewith may be properly and
     advantageously conducted at all times; provided that nothing in this
     Section 4.15 shall prevent the Guarantor or any such Subsidiary from
     discontinuing the use, operation or maintenance of any of such properties
     or disposing of any of them, if such discontinuance or disposal is, in the
     judgment of the Guarantor, desirable in the conduct of the business of the
     Guarantor or such Subsidiary.

               The Guarantor will provide or cause to be provided, for itself
     and its Restricted Subsidiaries, insurance (including appropriate self-
     insurance) against loss or damage of the kinds customarily insured against
     by corporations similarly situated and owning like properties, including,
     but not limited to, products liability insurance and public liability
     insurance, with reputable insurers or with the government of the United
     States of America, or an agency or instrumentality thereof, in such
     amounts, with such deductibles and by such methods as shall be customary
     for corporations similarly situated in the industry in which the Guarantor
     or such Restricted Subsidiary, as the case may be, is then conducting
     business.

               SECTION 4.16.  Notice of Defaults.  In the event that the Company
                            ------------------
     or the Guarantor becomes aware of any Default or Event of Default the
     Company or the Guarantor, as the case may be, promptly after it becomes
     aware thereof, will give written notice thereof to the Trustee.

               SECTION 4.17.  Compliance Certificates.  (a)  Each of the Company
                            -----------------------
     and the Guarantor shall deliver to the Trustee, within 90 days after the
     end of the Guarantor's fiscal year, an Officers' Certificate stating
     whether or not the signers know of any Default or Event of Default that
     occurred during such fiscal year.  Such certificates shall contain a
     certification from the principal executive officer, principal financial
     officer or principal accounting officer of the Company or the Guarantor, as
     the case may be, that a review has been conducted of the activities of the
     Company, the Guarantor and the Restricted Subsidiaries and the Company's,
     the Guarantor's and the Restricted Subsidiaries' performance under this
     Indenture and that the Guarantor and the Company have complied with all
     conditions and covenants under this Indenture.  For purposes of this
     Section 4.17, such compliance shall be determined without regard to any
     period of grace or requirement of notice provided under this Indenture.  If
     they do know of such a Default or Event of Default, the certificate shall
     describe any such Default or Event of Default and its status.  

               (b)  The Guarantor shall deliver to the Trustee, within 90 days
     after the end of its fiscal year, a certificate signed by the Guarantor's
     independent certified public accountants stating (i) that their audit
     examination has included a review of the terms of this Indenture and the
     Securities as they relate to accounting matters, (ii) that they have read
     the most recent Officers' Certificate delivered to the Trustee pursuant to
     paragraph (a) of this Section 4.17 and (iii) whether, in connection with
     their audit examination, anything came to their attention that caused them
     to believe that the Company or Guarantor, as the case may be, was not in
     compliance with any of the terms, covenants, provisions or conditions of
     Article Four and Section 5.01 of this Indenture as they pertain to
     accounting matters and, if any Default or Event of Default has come to
     their attention, specifying the nature and period of existence thereof;
     provided that such independent certified public accountants shall not be
     liable in respect of such statement by reason of any failure to obtain
     knowledge of any such Default or Event of Default that would not be
     disclosed in the course of an audit examination conducted in accordance
     with generally accepted auditing standards in effect at the date of such
     examination.

               (c)  Within 90 days of the end of each of the Guarantor's fiscal
     years, the Guarantor shall deliver to the Trustee a list of all Significant
     Subsidiaries.  The Trustee shall have no duty with respect to any such list
     except to keep it on file and available for inspection by the Holders.

               SECTION 4.18.  Commission Reports and Reports to Holders.  
                            -----------------------------------------
     Whether or not the Company or the Guarantor is required to file reports
     with the Commission, if any Securities are outstanding, the Company and the
     Guarantor shall file with the Commission all such reports and other
     information as they would be required to file with the Commission by
     Section 13(a) or 15(d) under the Exchange Act.  The Company shall supply
     the Trustee and each Holder, or shall supply to the Trustee for forwarding
     to each Holder, without cost to such Holder, copies of such reports or
     other information.

               SECTION 4.19.  Waiver of Stay, Extension or Usury Laws.  Each of 
                            ---------------------------------------
     the Company and the Guarantor covenants (to the extent that it may lawfully
     do so) that it will not at any time insist upon, or plead, or in any manner
     whatsoever claim or take the benefit or advantage of, any stay or extension
     law or any usury law or other law that would prohibit or forgive the
     Company or the Guarantor, as the case may be, from paying all or any
     portion of the principal of, premium, if any, or interest on the Securities
     as contemplated herein, wherever enacted, now or at any time hereafter in
     force, or that may affect the covenants or the performance of this
     Indenture; and (to the extent that it may lawfully do so) each of the
     Company and the Guarantor hereby expressly waives all benefit or advantage
     of any such law and covenants that it will not hinder, delay or impede the
     execution of any power herein granted to the Trustee, but will suffer and
     permit the execution of every such power as though no such law had been
     enacted.


                                     ARTICLE FIVE
                                SUCCESSOR CORPORATION

               SECTION 5.01.  When Company and Guarantor May Merge, Etc.  
                            -----------------------------------------
     Neither the Company nor the Guarantor shall consolidate with, merge with or
     into, or sell, convey, transfer, lease or otherwise dispose of all or
     substantially all of its property and assets (as an entirety or
     substantially an entirety in one transaction or a series of related
     transactions) to, any Person (other than a consolidation or merger with or
     into a Wholly Owned Restricted Subsidiary with a positive net worth;
     provided that, in connection with any such merger or consolidation, no
     consideration (other than Common Stock in the surviving Person, the Company
     or the Guarantor) shall be issued or distributed to the stockholders of the
     Company or the Guarantor) or permit any Person to merge with or into the
     Company or the Guarantor unless:

               (i)  the Company or the Guarantor shall be the continuing Person,
          or the Person (if other than the Company or the Guarantor) formed by
          such consolidation or into which the Company or the Guarantor is
          merged or that acquired or leased such property and assets of the
          Company or the Guarantor shall be a corporation organized and validly
          existing under the laws of the United States of America or any
          jurisdiction thereof and shall expressly assume, by a supplemental
          indenture, executed and delivered to the Trustee, all of the
          obligations of the Company or the Guarantor, as the case may be, under
          this Indenture;

               (ii) immediately after giving effect to such transaction, no
          Default or Event of Default shall have occurred and be continuing;

               (iii)     immediately after giving effect to such transaction on
          a pro forma basis, the Company or the Guarantor, as the case may be,
          or any Person becoming the successor obligor of the Securities or the
          Security Guarantee, as the case may be, shall have a Consolidated Net
          Worth equal to or greater than the Consolidated Net Worth of the
          Company or the Guarantor, as the case may be, immediately prior to
          such transaction; 

               (iv) immediately after giving effect to such transaction on a pro
          forma basis the Company, or any Person becoming the successor obligor
          of the Securities, as the case may be, could Incur at least $1.00 of
          Indebtedness under the first paragraph of Section 4.03(a); and

               (v)  the Company delivers to the Trustee an Officers' Certificate
          (attaching the arithmetic computations to demonstrate compliance with
          clauses (iii) and (iv) of this Section 5.01) and an Opinion of
          Counsel, in each case stating that such consolidation, merger or
          transfer and such supplemental indenture complies with this provision
          and that all conditions precedent provided for herein relating to such
          transaction have been complied with;

     provided, however, that clauses (iii) and (iv) of this Section 5.01 do not
     apply if, in the good faith determination of the Board of Directors of the
     Guarantor, whose determination shall be evidenced by a Board Resolution,
     the principal purpose of such transaction is part of a plan to change the
     jurisdiction of incorporation of the Company or the Guarantor to a state of
     the United States; and provided further that any such transaction shall not
     have as one of its purposes the evasion of the foregoing limitations.

               SECTION 5.02.  Successor Substituted.  Upon any consolidation or
                            ---------------------
     merger, or any sale, conveyance, transfer or other disposition of all or
     substantially all of the property and assets of the Company or the
     Guarantor in accordance with Section 5.01 of this Indenture, the successor
     Person formed by such consolidation or into which the Company or the
     Guarantor is merged or to which such sale, conveyance, transfer or other
     disposition is made shall succeed to, and be substituted for, and may
     exercise every right and power of, the Company or the Guarantor, as the
     case may be, under this Indenture with the same effect as if such successor
     Person had been named as the Company or the Guarantor, as the case may be,
     herein.


                                     ARTICLE SIX
                                 DEFAULT AND REMEDIES

               SECTION 6.01.  Events of Default.  An "Event of Default" shall 
                            -----------------       ----------------
     occur with respect to the Securities if:

               (a)  the Company defaults in the payment of the principal of (or
          premium, if any, on) any Security when the same becomes due and
          payable at maturity, upon acceleration, redemption or otherwise;

               (b)  the Company defaults in the payment of interest on any
          Security when the same becomes due and payable, and such default
          continues for a period of 30 days;

               (c)  the Company or the Guarantor defaults in the performance of
          or breaches any other covenant or agreement of the Company or the
          Guarantor in this Indenture or under the Securities and such default
          or breach continues for a period of 30 consecutive days after written
          notice to the Company or the Guarantor by the Trustee or the Holders
          of 25% or more in aggregate principal amount at maturity of the
          Securities;

               (d)  there occurs with respect to any issue or issues of
          Indebtedness of the Company, the Guarantor or any Significant
          Subsidiary having an outstanding principal amount at maturity of $10
          million or more in the aggregate for all such issues of all such
          Persons, whether such Indebtedness now exists or shall hereafter be
          created, (I) an event of default that has caused the holder thereof to
          declare such Indebtedness to be due and payable prior to its Stated
          Maturity and such Indebtedness has not been discharged in full or such
          acceleration has not been rescinded or annulled within 30 days of such
          acceleration and/or (II) the failure to make a principal payment at
          the final (but not any interim) fixed maturity and such defaulted
          payment shall not have been made, waived or extended within 30 days of
          such payment default;

               (e)  any final judgment or order (not covered by insurance) for
          the payment of money in excess of $10 million in the aggregate for all
          such final judgments or orders against all such Persons (treating any
          deductibles, self-insurance or retention as not so covered) shall be
          rendered against the Company, the Guarantor or any Significant
          Subsidiary and shall not be paid or discharged, and there shall be any
          period of 30 consecutive days following entry of the final judgment or
          order that causes the aggregate amount for all such final judgments or
          orders outstanding and not paid or discharged against all such Persons
          to exceed $10 million during which a stay of enforcement of such final
          judgment or order, by reason of a pending appeal or otherwise, shall
          not be in effect;

               (f)  a court having jurisdiction in the premises enters a decree
          or order for (A) relief in respect of the Company, the Guarantor or
          any Significant Subsidiary in an involuntary case under any applicable
          bankruptcy, insolvency or other similar law now or hereafter in
          effect, (B) appointment of a receiver, liquidator, assignee,
          custodian, trustee, sequestrator or similar official of the Company,
          the Guarantor or any Significant Subsidiary or for all or
          substantially all of the property and assets of the Company, the
          Guarantor or any Significant Subsidiary or (C) the winding up or
          liquidation of the affairs of the Company, the Guarantor or any
          Significant Subsidiary and, in each case, such decree or order shall
          remain unstayed and in effect for a period of 30 consecutive days; or

               (g)  the Company, the Guarantor or any Significant Subsidiary
          (A) commences a voluntary case under any applicable bankruptcy,
          insolvency or other similar law now or hereafter in effect, or
          consents to the entry of an order for relief in an involuntary case
          under any such law, (B) consents to the appointment of or taking
          possession by a receiver, liquidator, assignee, custodian, trustee,
          sequestrator or similar official of the Company, the Guarantor or any
          Significant Subsidiary or for all or substantially all of the property
          and assets of the Company, the Guarantor or any Significant Subsidiary
          or (C) effects any general assignment for the benefit of creditors.

               SECTION 6.02.  Acceleration.  If an Event of Default (other than 
                              ------------
     an Event of Default specified in clause (f) or (g) of Section 6.01 that
     occurs with respect to the Company or the Guarantor) occurs and is
     continuing under this Indenture, the Trustee or the Holders of at least 25%
     in aggregate principal amount at maturity of the Securities, then
     outstanding, by written notice to the Company (and to the Trustee if such
     notice is given by the Holders), may, and the Trustee at the request of
     such Holders shall, declare the Accreted Value of, premium, if any, and
     accrued interest, if any, on the Securities to be immediately due and
     payable.  Upon a declaration of acceleration, such Accreted Value of,
     premium, if any, and accrued interest, if any, shall be immediately due and
     payable.  In the event of a declaration of acceleration because an Event of
     Default set forth in clause (d) of Section 6.01 has occurred and is
     continuing, such declaration of acceleration shall be automatically
     rescinded and annulled if the event of default triggering such Event of
     Default pursuant to clause (d) shall be remedied or cured by the Company,
     the Guarantor or the relevant Significant Subsidiary or waived by the
     holders of the relevant Indebtedness within 60 days after the declaration
     of acceleration with respect thereto.  If an Event of Default specified in
     clause (f) or (g) of Section 6.01 occurs with respect to the Company or the
     Guarantor, the Accreted Value of, premium, if any, and accrued interest, if
     any, on the Securities then outstanding shall ipso facto become and be
     immediately due and payable without any declaration or other act on the
     part of the Trustee or any Holder.

               At any time after such a declaration of acceleration, but before
     a judgment or decree for the payment of the money due has been obtained by
     the Trustee, the Holders of at least a majority in principal amount at
     maturity of the outstanding Securities by written notice to the Company and
     to the Trustee may waive all past Defaults and rescind and annul such
     declaration of acceleration and its consequences if (a) the Company or the
     Guarantor has paid or deposited with the Trustee a sum sufficient to pay
     (i) all sums paid or advanced by the Trustee hereunder and the reasonable
     compensation, expenses, disbursements and advances of the Trustee, its
     agents and counsel, (ii) all overdue interest on all Securities, (iii) the
     principal of and premium, if any, on any Securities that have become due
     otherwise than by such declaration or occurrence of acceleration and
     interest thereon at the rate prescribed therefor by such Securities, and
     (iv) to the extent that payment of such interest is lawful, interest upon
     overdue interest at the rate prescribed therefor by such Securities,
     (b) all existing Events of Default, other than the non-payment of the
     Accreted Value of, premium, if any, and accrued interest on the Securities
     that have become due solely by such declaration of acceleration, have been
     cured or waived and (c) the rescission would not conflict with any judgment
     or decree of a court of competent jurisdiction.

               SECTION 6.03.  Other Remedies.  If an Event of Default occurs and
                             --------------
     is continuing, the Trustee may pursue any available remedy by proceeding at
     law or in equity to collect the payment of principal of, premium, if any,
     or interest on the Securities or to enforce the performance of any
     provision of the Securities or this Indenture.

               The Trustee may maintain a proceeding even if it does not possess
     any of the Securities or does not produce any of them in the proceeding.

               SECTION 6.04.  Waiver of Past Defaults.  Subject to Sections 
                            -----------------------
     6.02, 6.07 and 9.02, the Holders of at least a majority in principal amount
     at maturity of the outstanding Securities, by notice to the Trustee, may
     waive an existing Default or Event of Default and its consequences, except
     a Default in the payment of the Accreted Value of, premium, if any, or
     accrued interest on any Security as specified in clause (a) or (b) of
     Section 6.01 or in respect of a covenant or provision of this Indenture
     which cannot be modified or amended without the consent of the holder of
     each outstanding Security affected.  Upon any such waiver, such Default
     shall cease to exist, and any Event of Default arising therefrom shall be
     deemed to have been cured, for every purpose of this Indenture; but no such
     waiver shall extend to any subsequent or other Default or Event of Default
     or impair any right consequent thereto.

               SECTION 6.05.  Control by Majority.  The Holders of at least a 
                            -------------------
     majority in aggregate principal amount at maturity of the outstanding
     Securities may direct the time, method and place of conducting any
     proceeding for any remedy available to the Trustee or exercising any trust
     or power conferred on the Trustee; provided that the Trustee may refuse to
     follow any direction that conflicts with law or this Indenture, that may
     involve the Trustee in personal liability, or that the Trustee determines
     in good faith may be unduly prejudicial to the rights of Holders not
     joining in the giving of such direction; and provided further that the
     Trustee may take any other action it deems proper that is not inconsistent
     with any directions received from Holders of Securities pursuant to this
     Section 6.05.

               SECTION 6.06.  Limitation on Suits.  A Holder may not institute
                             -------------------
     any proceeding, judicial or otherwise, with respect to this Indenture or
     the Securities, or for the appointment of a receiver or trustee, or for any
     other remedy hereunder, unless:

               (i)  such Holder has previously given to the Trustee written
          notice of a continuing Event of Default;

               (ii) the Holders of at least 25% in aggregate principal amount at
          maturity of outstanding Securities shall have made written request to
          the Trustee to institute proceedings in respect of such Event of
          Default in its own name as Trustee hereunder;

               (iii)     such Holder or Holders have offered to the Trustee
          indemnity reasonably satisfactory to the Trustee against any costs,
          liabilities or expenses to be incurred in compliance with such
          request;

               (iv) the Trustee for 60 days after its receipt of such notice,
          request and offer of indemnity has failed to institute any such
          proceeding; and

               (v)  during such 60-day period, the Holders of a majority in
          aggregate principal amount at maturity of the outstanding Securities
          have not given the Trustee a direction that is inconsistent with such
          written request.

               For purposes of Section 6.05 of this Indenture and this Section
     6.06, the Trustee shall comply with TIA Section 316(a) in making any
     determination of whether the Holders of the required aggregate principal
     amount at maturity of outstanding Securities have concurred in any request
     or direction of the Trustee to pursue any remedy available to the Trustee
     or the Holders with respect to this Indenture or the Securities or
     otherwise under the law.

               A Holder may not use this Indenture to prejudice the rights of
     another Holder or to obtain a preference or priority over such other
     Holder.

               SECTION 6.07.  Rights of Holders to Receive Payment.  
                            ------------------------------------
     Notwithstanding any other provision of this Indenture, the right of any
     Holder of a Security to receive payment of principal of, premium, if any,
     or interest accrued on such Holder's Security on or after the respective
     due dates expressed on such Security, or to bring suit for the enforcement
     of any such payment on or after such respective dates, shall not be
     impaired or affected without the consent of such Holder.

               SECTION 6.08.  Collection Suit by Trustee.  If an Event of 
                            --------------------------
     Default in payment of principal, premium or interest specified in clause
     (a), (b) or (c) of Section 6.01 occurs and is continuing, the Trustee may
     recover judgment in its own name and as trustee of an express trust against
     the Company or any other obligor of the Securities for the whole amount of
     principal, premium, if any, and accrued interest remaining unpaid, together
     with interest on overdue principal, premium, if any, and, to the extent
     that payment of such interest is lawful, interest on overdue installments
     of interest, in each case at the rate specified in the Securities, and such
     further amount as shall be sufficient to cover the costs and expenses of
     collection, including the reasonable compensation, expenses, disbursements
     and advances of the Trustee, its agents and counsel.

               SECTION 6.09.  Trustee May File Proofs of Claim.  The Trustee may
                            --------------------------------
     file such proofs of claim and other papers or documents as may be necessary
     or advisable in order to have the claims of the Trustee (including any
     claim for the reasonable compensation, expenses, disbursements and advances
     of the Trustee, its agents and counsel, and any other amounts due the
     Trustee under Section 7.07) and the Holders allowed in any judicial
     proceedings relative to the Company (or any other obligor of the
     Securities), its creditors or its property and shall be entitled and
     empowered to collect and receive any monies, securities or other property
     payable or deliverable upon conversion or exchange of the Securities or
     upon any such claims and to distribute the same, and any custodian,
     receiver, assignee, trustee, liquidator, sequestrator or other similar
     official in any such judicial proceeding is hereby authorized by each
     Holder to make such payments to the Trustee and, in the event that the
     Trustee shall consent to the making of such payments directly to the
     Holders, to pay to the Trustee any amount due to it for the reasonable
     compensation, expenses, disbursements and advances of the Trustee, its
     agent and counsel, and any other amounts due the Trustee under Section
     7.07.  Nothing herein contained shall be deemed to empower the Trustee to
     authorize or consent to, or accept or adopt on behalf of any Holder, any
     plan of reorganization, arrangement, adjustment or composition affecting
     the Securities or the rights of any Holder thereof, or to authorize the
     Trustee to vote in respect of the claim of any Holder in any such
     proceeding.

               SECTION 6.10.  Priorities.  If the Trustee collects any money 
                            ----------
     pursuant to this Article Six, it shall pay out the money in the following
     order:

               First:  to the Trustee for all amounts due under Section 7.07;

               Second:  to Holders for amounts then due and unpaid for principal
          of, premium, if any, and interest on the Securities in respect of
          which or for the benefit of which such money has been collected,
          ratably, without preference or priority of any kind, according to the
          amounts due and payable on such Securities for principal, premium, if
          any, and interest, respectively; and

               Third:  to the Company or any other obligors of the Securities,
          as their interests may appear, or as a court of competent jurisdiction
          may direct.

               The Trustee, upon prior written notice to the Company, may fix a
     record date and payment date for any payment to Holders pursuant to this
     Section 6.10.

               SECTION 6.11.  Undertaking for Costs.  In any suit for the 
                            ---------------------
     enforcement of any right or remedy under this Indenture or in any suit
     against the Trustee for any action taken or omitted by it as Trustee, a
     court may require any party litigant in such suit to file an undertaking to
     pay the costs of the suit, and the court may assess reasonable costs,
     including reasonable attorneys' fees, against any party litigant in the
     suit having due regard to the merits and good faith of the claims or
     defenses made by the party litigant.  This Section 6.11 does not apply to a
     suit by the Trustee, a suit by a Holder pursuant to Section 6.07 of this
     Indenture, or a suit by Holders of more than 10% in principal amount at
     maturity of the outstanding Securities.

               SECTION 6.12.  Restoration of Rights and Remedies.  If the 
                            ----------------------------------
     Trustee or any Holder has instituted any proceeding to enforce any right or
     remedy under this Indenture and such proceeding has been discontinued or
     abandoned for any reason, or has been determined adversely to the Trustee
     or to such Holder, then, and in every such case, subject to any
     determination in such proceeding, the Company, the Trustee and the Holders
     shall be restored severally and respectively to their former positions
     hereunder and thereafter all rights and remedies of the Company, the
     Trustee and the Holders shall continue as though no such proceeding had
     been instituted.

               SECTION 6.13.  Rights and Remedies Cumulative.  Except as
                            ------------------------------
     otherwise provided with respect to the replacement or payment of mutilated,
     destroyed, lost or wrongfully taken Securities in Section 2.09, no right or
     remedy herein conferred upon or reserved to the Trustee or to the Holders
     is intended to be exclusive of any other right or remedy, and every right
     and remedy shall, to the extent permitted by law, be cumulative and in
     addition to every other right and remedy given hereunder or now or
     hereafter existing at law or in equity or otherwise.  The assertion or
     employment of any right or remedy hereunder, or otherwise, shall not
     prevent the concurrent assertion or employment of any other appropriate
     right or remedy.

               SECTION 6.14.  Delay or Omission Not Waiver.  No delay or 
                            ----------------------------
     omission of the Trustee or of any Holder to exercise any right or remedy
     accruing upon any Event of Default shall impair any such right or remedy or
     constitute a waiver of any such Event of Default or an acquiescence
     therein.  Every right and remedy given by this Article Six or by law to the
     Trustee or to the Holders may be exercised from time to time, and as often
     as may be deemed expedient, by the Trustee or by the Holders, as the case
     may be.


                                    ARTICLE SEVEN
                                       TRUSTEE

               SECTION 7.01.  General.  The duties and responsibilities of the 
                            -------
     Trustee shall be as provided by the TIA and as set forth herein. 
     Notwithstanding the foregoing, no provision of this Indenture shall require
     the Trustee to expend or risk its own funds or otherwise incur any
     financial liability in the performance of any of its duties hereunder, or
     in the exercise of any of its rights or powers, if it shall have reasonable
     grounds for believing that repayment of such funds or adequate indemnity
     against such risk or liability is not reasonably assured to it.  Whether or
     not therein expressly so provided, every provision of this Indenture
     relating to the conduct or affecting the liability of or affording
     protection to the Trustee shall be subject to the provisions of this
     Article Seven.

               SECTION 7.02.  Certain Rights of Trustee.  Subject to TIA 
                            -------------------------
     Sections 315(a) through (d):

               (i)  the Trustee may rely and shall be protected in acting or
          refraining from acting upon any resolution, certificate, statement,
          instrument, opinion, report, notice, request, direction, consent,
          order, bond, debenture, note, other evidence of indebtedness or other
          paper or document believed by it to be genuine and to have been signed
          or presented by the proper person.  The Trustee need not investigate
          any fact or matter stated in the document and may in good faith
          conclusively rely as to the truth of the statements and the
          correctness of the opinions therein;

               (ii) before the Trustee acts or refrains from acting, it may
          require an Officers' Certificate or an Opinion of Counsel, which shall
          conform to Section 11.04.  The Trustee shall not be liable for any
          action it takes or omits to take in good faith in reliance on such
          certificate, opinion and/or an accountants' certificate if required
          under the TIA;

               (iii)     the Trustee may act through its attorneys and agents
          and shall not be responsible for the misconduct or negligence of any
          agent appointed with due care;

               (iv) the Trustee shall be under no obligation to exercise any of
          the rights or powers vested in it by this Indenture at the request or
          direction of any of the Holders, unless such Holders shall have
          offered to the Trustee security or indemnity reasonably satisfactory
          to it against the costs, expenses and liabilities that might be
          incurred by it in compliance with such request or direction;

               (v)  the Trustee shall not be liable for any action it takes or
          omits to take in good faith that it believes to be authorized or
          within its rights or powers or for any action it takes or omits to
          take in accordance with the direction of the Holders of a majority in
          principal amount at maturity of the Outstanding Securities relating to
          the time, method and place of conducting any proceeding for any remedy
          available to the Trustee, or exercising any trust or power conferred
          upon the Trustee, under this Indenture; provided that the Trustee's
          conduct does not constitute gross negligence or bad faith;

               (vi) whenever in the administration of this Indenture the Trustee
          shall deem it desirable that a making be proved or established prior
          to taking, suffering or omitting any action hereunder, the Trustee
          (unless other evidence be herein specifically prescribed) may, in the
          absence of bad faith on its part, rely upon an Officer's Certificate;
          and

               (vii)     the Trustee shall not be bound to make any
          investigation into the facts or matters stated in any resolution,
          certificate, statement, instrument, opinion, report, notice, request,
          direction, consent, order, bond, debenture, note, other evidence of
          indebtedness or other paper or document, but the Trustee, in its
          discretion, may make such further inquiry or investigation into such
          facts or matters as it may see fit, and, if the Trustee shall
          determine to make such further inquiry or investigation, it shall be
          entitled to examine the books, records and premises of the Company
          personally or by agent or attorney.

               SECTION 7.03.  Individual Rights of Trustee.  The Trustee, in its
                            ----------------------------
     individual or any other capacity, may become the owner or pledgee of
     Securities and may otherwise deal with the Company or its Affiliates with
     the same rights it would have if it were not the Trustee.  Any Agent may do
     the same with like rights.  However, the Trustee is subject to TIA Sections
     310(b) and 311.

               SECTION 7.04.  Trustee's Disclaimer.  The Trustee (i) makes no
                            --------------------
     representation as to the validity or adequacy of this Indenture or the
     Securities, (ii) shall not be accountable for the Company's use or
     application of the proceeds from the Securities and (iii) shall not be
     responsible for any statement in the Securities other than its certificate
     of authentication.

               SECTION 7.05.  Notice of Default.  If any Default or any Event of
                            -----------------
     Default occurs and is continuing and if such Default or Event of Default is
     known to a trust officer of the Trustee, the Trustee shall mail to each
     Holder in the manner and to the extent provided in TIA Section 313(c)
     notice of the Default or Event of Default within 90 days after it occurs,
     unless such Default or Event of Default has been cured; provided, however,
     that, except in the case of a default in the payment of the principal of,
     premium, if any, or interest on any Security, the Trustee shall be
     protected in withholding such notice if and so long as the board of
     directors, the executive committee or a trust committee of directors and/or
     Responsible Officers of the Trustee in good faith determine that the
     withholding of such notice is in the interest of the Holders.

               SECTION 7.06.  Reports by Trustee to Holders.  Within 60 days
                            -----------------------------
     after each May 15, beginning with May 15, 1997, the Trustee shall mail to
     each Holder as provided in TIA Section 313(c) a brief report that complies
     with TIA Section 313(a) dated as of such May 15, if required by TIA Section
     313(a).

               SECTION 7.07.  Compensation and Indemnity.  The Company shall pay
                            --------------------------
     to the Trustee such compensation as shall be agreed upon in writing for its
     services.  The compensation of the Trustee shall not be limited by any law
     on compensation of a trustee of an express trust.  The Company shall
     reimburse the Trustee upon request for all reasonable out-of-pocket
     expenses and advances incurred or made by the Trustee.  Such expenses shall
     include the reasonable compensation and expenses of the Trustee's agents
     and counsel.

               The Company shall indemnify the Trustee for, and hold it harmless
     against, any loss or liability or expense incurred by it without negligence
     or bad faith on its part in connection with the acceptance or
     administration of this Indenture and its duties under this Indenture and
     the Securities, including the costs and expenses of defending itself
     against any claim or liability and of complying with any process served
     upon it or any of its officers in connection with the exercise or
     performance of any of its powers or duties under this Indenture and the
     Securities.

               To secure the Company's payment obligations in this Section 7.07,
     the Trustee shall have a lien prior to the Securities on all money or
     property held or collected by the Trustee, in its capacity as Trustee,
     except money or property held in trust to pay principal of, premium, if
     any, and interest on particular Securities.

               If the Trustee incurs expenses or renders services after the
     occurrence of an Event of Default specified in clause (f) or (g) of Section
     6.01, the expenses and the compensation for the services will be intended
     to constitute expenses of administration under Title 11 of the United
     States Bankruptcy Code or any applicable federal or state law for the
     relief of debtors.

               SECTION 7.08.  Replacement of Trustee.  A resignation or removal
                            ----------------------
     of the Trustee and appointment of a successor Trustee shall become
     effective only upon the successor Trustee's acceptance of appointment as
     provided in this Section 7.08.

               The Trustee may resign at any time by so notifying the Company in
     writing at least 30 days prior to the date of the proposed resignation. 
     The Holders of a majority in principal amount at maturity of the
     outstanding Securities may remove the Trustee by so notifying the Trustee
     in writing and may appoint a successor Trustee with the consent of the
     Company.  The Company may at any time remove the Trustee, by Company Order
     given at least 30 days prior to the date of the proposed removal.

               If the Trustee resigns or is removed, or if a vacancy exists in
     the office of Trustee for any reason, the Company shall promptly appoint a
     successor Trustee.  Within one year after the successor Trustee takes
     office, the Holders of a majority in principal amount at maturity of the
     outstanding Securities may appoint a successor Trustee to replace the
     successor Trustee appointed by the Company.  If the successor Trustee does
     not deliver its written acceptance required by the next succeeding
     paragraph of this Section 7.08 within 30 days after the retiring Trustee
     resigns or is removed, the retiring Trustee, the Company or the Holders of
     a majority in principal amount at maturity of the outstanding Securities
     may petition any court of competent jurisdiction for the appointment of a
     successor Trustee.

               A successor Trustee shall deliver a written acceptance of its
     appointment to the retiring Trustee and to the Company.  Immediately after
     the delivery of such written acceptance, subject to the lien provided in
     Section 7.07, (i) the retiring Trustee shall transfer all property held by
     it as Trustee to the successor Trustee, (ii) the resignation or removal of
     the retiring Trustee shall become effective and (iii) the successor Trustee
     shall have all the rights, powers and duties of the Trustee under this
     Indenture.  A successor Trustee shall mail notice of its succession to each
     Holder.

               If the Trustee is no longer eligible under Section 7.10, any
     Holder who satisfies the requirements of TIA Section 310(b) may petition
     any court of competent jurisdiction for the removal of the Trustee and the
     appointment of a successor Trustee.

               The Company shall give notice of any resignation and any removal
     of the Trustee and each appointment of a successor Trustee to all Holders. 
     Each notice shall include the name of the successor Trustee and the address
     of its Corporate Trust Office.

               Notwithstanding replacement of the Trustee pursuant to this
     Section 7.08, the Company's obligation under Section 7.07 shall continue
     for the benefit of the retiring Trustee.

               SECTION 7.09.  Successor Trustee by Merger, Etc.  If the Trustee
                            --------------------------------
     consolidates with, merges or converts into, or transfers all or
     substantially all of its corporate trust business to, another corporation
     or national banking association, the resulting, surviving or transferee
     corporation or national banking association without any further act shall
     be the successor Trustee with the same effect as if the successor Trustee
     had been named as the Trustee herein.

               SECTION 7.10.  Eligibility.  This Indenture shall always have a
                            -----------
     Trustee who satisfies the requirements of TIA Section 310(a)(1).  The
     Trustee shall have a combined capital and surplus of at least $25,000,000
     as set forth in its most recent published annual report of condition.

               SECTION 7.11.  Money Held in Trust.  The Trustee shall not be 
                            -------------------
     liable for interest on any money received by it except as the Trustee may
     agree with the Company.  Money held in trust by the Trustee need not be
     segregated from other funds except to the extent required by law and except
     for money held in trust under Article Eight of this Indenture.

               SECTION 7.12.  Withholding Taxes.  The Trustee, as agent for the 
                            -----------------
     Company, shall exclude and withhold from each payment of principal and
     interest and other amounts due hereunder or under the Securities any and
     all withholding taxes applicable thereto as required by law.  The Trustee
     agrees to act as such withholding agent and, in connection therewith,
     whenever any present or future taxes or similar charges are required to be
     withheld with respect to any amounts payable in respect of the Securities,
     to withhold such amounts and timely pay the same to the appropriate
     authority in the name of and on behalf of the holders of the Securities,
     that it will file any necessary withholding tax returns or statements when
     due, and that, as promptly as possible after the payment thereof, it will
     deliver to each holder of a Security appropriate documentation showing the
     payment thereof, together with such additional documentary evidence as such
     holders may reasonably request from time to time.


                                    ARTICLE EIGHT
                                DISCHARGE OF INDENTURE

               SECTION 8.01.  Termination of Company's Obligations.  Except as 
                            ------------------------------------
     otherwise provided in this Section 8.01, the Company may terminate its
     obligations under the Securities and this Indenture if:

               (i)  all Securities previously authenticated and delivered (other
          than destroyed, lost or stolen Securities that have been replaced or
          Securities that are paid pursuant to Section 4.01 or Securities for
          whose payment money or securities have theretofore been held in trust
          and thereafter repaid to the Company, as provided in Section 8.05)
          have been delivered to the Trustee for cancellation and the Company
          has paid all sums payable by it hereunder; or

               (ii) (A) the Securities mature within one year or all of them are
          to be called for redemption within one year under arrangements
          satisfactory to the Trustee for giving the notice of redemption,
          (B) the Company or the Guarantor irrevocably deposits in trust with
          the Trustee during such one-year period, under the terms of an
          irrevocable trust agreement in form and substance satisfactory to the
          Trustee, as trust funds solely for the benefit of the Holders for that
          purpose, money or U.S. Government Obligations sufficient (in the
          opinion of a nationally recognized firm of independent public
          accountants expressed in a written certification thereof delivered to
          the Trustee), without consideration of any reinvestment of any
          interest thereon, to pay principal, premium, if, any, and interest on
          the Securities to maturity or redemption, as the case may be, and to
          pay all other sums payable by it hereunder, (C) no Default or Event of
          Default with respect to the Securities shall have occurred and be
          continuing on the date of such deposit, (D) such deposit will not
          result in a breach or violation of, or constitute a default under,
          this Indenture or any other agreement or instrument to which the
          Company or the Guarantor is a party or by which it is bound and (E)
          the Company has delivered to the Trustee an Officers' Certificate and
          an Opinion of Counsel, in each case stating that all conditions
          precedent provided for herein relating to the satisfaction and
          discharge of this Indenture have been complied with.

               With respect to the foregoing clause (i), the Company's
     obligations under Section 7.07 shall survive.  With respect to the
     foregoing clause (ii), the Company's obligations in Sections 2.02, 2.03,
     2.04, 2.05, 2.06, 2.07, 2.08, 2.09, 2.14, 4.01, 4.02, 7.07, 7.08, 8.04,
     8.05 and 8.06 shall survive until the Securities are no longer outstanding.
     Thereafter, only the Company's obligations in Sections 7.07, 8.05 and 8.06
     shall survive.  After any such irrevocable deposit, the Trustee upon
     request shall acknowledge in writing the discharge of the Company's
     obligations, as the case may be, under the Securities and this Indenture
     except for those surviving obligations specified above.

               SECTION 8.02.  Defeasance and Discharge of Indenture.  The 
                            -------------------------------------
     Company will be deemed to have paid and will be discharged from any and all
     obligations in respect of the Securities on the 123rd day (or, to the
     extent applicable under clause (D) below, one year) after the date of the
     deposit referred to in clause (A) of this Section 8.02 if:

               (A)  with reference to this Section 8.02, the Company or the
          Guarantor has irrevocably deposited or caused to be irrevocably
          deposited with the Trustee (or another trustee satisfying the
          requirements of Section 7.10 of this Indenture) and conveyed all
          right, title and interest for the benefit of the Holders, under the
          terms of an irrevocable trust agreement in form and substance
          satisfactory to the Trustee as trust funds in trust, specifically
          pledged to the Trustee for the benefit of the Holders as security for
          payment of the principal of, premium, if any, and interest, if any, on
          the Securities, and dedicated solely to, the benefit of the Holders,
          in and to (1) money in an amount, (2) U.S. Government Obligations
          that, through the payment of interest, premium, if any, and principal
          in respect thereof in accordance with their terms, will provide, not
          later than one day before the due date of any payment referred to in
          this clause (A), money in an amount or (3) a combination thereof in an
          amount sufficient, in the opinion of a nationally recognized firm of
          independent public accountants expressed in a written certification
          thereof delivered to the Trustee, to pay and discharge, without
          consideration of the reinvestment of such interest and after payment
          of all federal, state and local taxes or other charges and assessments
          in respect thereof payable by the Trustee, the principal of, premium,
          if any, and accrued interest on the outstanding Securities at the
          Stated Maturity of such principal or interest; provided that the
          Trustee shall have been irrevocably instructed to apply such money or
          the proceeds of such U.S. Government Obligations to the payment of
          such principal, premium, if any, and interest with respect to the
          Securities;

               (B)  such deposit will not result in a breach or violation of, or
          constitute a default under, this Indenture or any other agreement or
          instrument to which the Company or the Guarantor is a party or by
          which it is bound;

               (C)  immediately after giving effect to such deposit on a pro
          forma basis, no Default or Event of Default shall have occurred and be
          continuing on the date of such deposit; and no Default or Event of
          Default shall occur during the period ending on the 123rd day (or one
          year) after such date of deposit and such deposit shall not result in
          a breach or violation of, or constitute a default under, any other
          agreement to which the Company or the Guarantor is a party or by which
          the Company or the Guarantor is bound;

               (D)  the Company shall have delivered to the Trustee (1) either
          (x) a ruling directed to the Trustee received from the Internal
          Revenue Service to the effect that the Holders will not recognize
          income, gain or loss for federal income tax purposes as a result of
          the Company's exercise of its option under this Section 8.02 and will
          be subject to federal income tax on the same amount and in the same
          manner and at the same times as would have been the case if such
          option had not been exercised or (y) an Opinion of Counsel to the same
          effect as the ruling described in clause (x) above accompanied by a
          ruling to that effect published by the Internal Revenue Service,
          unless there has been a change in the applicable federal income tax
          law since the date of this Indenture such that a ruling from the
          Internal Revenue Service is no longer required and (2) an Opinion of
          Counsel to the effect that (x) the creation of the defeasance trust
          does not violate the Investment Company Act of 1940 and (y) after the
          passage of 123 days following the deposit (except, with respect to any
          trust funds for the account of any Holder who may be deemed to be an
          "insider" for purposes of the United States Bankruptcy Code, after one
          year following the deposit), the trust funds will not be subject to
          the effect of Section 547 of the United States Bankruptcy Code or
          Section 15 of the New York Debtor and Creditor Law in a case commenced
          by or against the Company or the Guarantor under either such statute,
          and either (I) the trust funds will no longer remain the property of
          the Company or the Guarantor (and therefore will not be subject to the
          effect of any applicable bankruptcy, insolvency, reorganization or
          similar laws affecting creditors' rights generally) or (II) if a court
          were to rule under any such law in any case or proceeding that the
          trust funds remained property of the Company or the Guarantor
          (a) assuming such trust funds remained in the possession of the
          Trustee prior to such court ruling to the extent not paid to the
          Holders, the Trustee will hold, for the benefit of the Holders, a
          valid and perfected security interest in such trust funds that is not
          avoidable in bankruptcy or otherwise except for the effect of Section
          552(b) of the United States Bankruptcy Code on interest on the trust
          funds accruing after the commencement of a case under such statute and
          (b) the Holders will be entitled to receive adequate protection of
          their interests in such trust funds if such trust funds are used in
          such case or proceeding;

               (E)  if the Securities are then listed on a national securities
          exchange, the Company shall have delivered to the Trustee an Opinion
          of Counsel to the effect that such deposit defeasance and discharge
          will not cause the Securities to be delisted; and

               (F)  the Company has delivered to the Trustee an Officers'
          Certificate and an Opinion of Counsel, in each case stating that all
          conditions precedent provided for herein relating to the defeasance
          contemplated by this Section 8.02 have been complied with.

               Notwithstanding the foregoing, prior to the end of the 123-day
     (or one year) period referred to in clause (D)(2)(y) of this Section 8.02,
     none of the Company's obligations under this Indenture shall be discharged.
     Subsequent to the end of such 123-day (or one year) period with respect to
     this Section 8.02, the Company's obligations in Sections 2.02, 2.03, 2.04,
     2.05, 2.06, 2.07, 2.08, 2.09, 2.14, 4.01, 4.02, 7.07, 7.08, 8.05 and 8.06
     shall survive until the Securities are no longer outstanding.  Thereafter,
     only the Company's obligations in Sections 7.07, 8.05 and 8.06 shall
     survive.  If and when a ruling from the Internal Revenue Service or an
     Opinion of Counsel referred to in clause (D)(1) of this Section 8.02 may be
     provided specifically without regard to, and not in reliance upon, the
     continuance of the Company's obligations under Section 4.01, then the
     Company's obligations under such Section 4.01 shall cease upon delivery to
     the Trustee of such ruling or Opinion of Counsel and compliance with the
     other conditions precedent provided for herein relating to the defeasance
     contemplated by this Section 8.02.

               After any such irrevocable deposit, the Trustee upon request
     shall acknowledge in writing the discharge of the Company's and the
     Guarantor's obligations under the Securities and this Indenture except for
     those surviving obligations in the immediately preceding paragraph.

               SECTION 8.03.  Defeasance of Certain Obligations.  The Company
                            ---------------------------------
     and the Guarantor may omit to comply with any term, provision or condition
     set forth in clauses (iii) and (iv) of Section 5.01 and Sections 4.03
     through 4.18, and clause (c) of Section 6.01 with respect to clauses (iii)
     and (iv) of Section 5.01 and Sections 4.03 through 4.18, and clauses (d)
     and (e) of Section 6.01 shall be deemed not to be Events of Default, in
     each case with respect to the outstanding Securities if:

               (i)  with reference to this Section 8.03, the Company or the
          Guarantor has irrevocably deposited or caused to be irrevocably
          deposited with the Trustee (or another trustee satisfying the
          requirements of Section 7.10) and conveyed all right, title and
          interest to the Trustee for the benefit of the Holders, under the
          terms of an irrevocable trust agreement in form and substance
          satisfactory to the Trustee as trust funds in trust, specifically
          pledged to the Trustee for the benefit of the Holders as security for
          payment of the principal of, premium, if any, and interest, if any, on
          the Securities, and dedicated solely to, the benefit of the Holders,
          in and to (A) money in an amount, (B) U.S. Government Obligations
          that, through the payment of interest and principal in respect thereof
          in accordance with their terms, will provide, not later than one day
          before the due date of any payment referred to in this clause (i),
          money in an amount or (C) a combination thereof in an amount
          sufficient, in the opinion of a nationally recognized firm of
          independent public accountants expressed in a written certification
          thereof delivered to the Trustee, to pay and discharge, without
          consideration of the reinvestment of such interest and after payment
          of all federal, state and local taxes or other charges and assessments
          in respect thereof payable by the Trustee, the principal of, premium,
          if any, and accrued interest on the outstanding Securities on the
          Stated Maturity of such principal or interest; provided that the
          Trustee shall have been irrevocably instructed to apply such money or
          the proceeds of such U.S. Government Obligations to the payment of
          such principal, premium, if any, and interest with respect to the
          Securities;

               (ii) such deposit will not result in a breach or violation of, or
          constitute a default under, this Indenture or any other agreement or
          instrument to which the Company or the Guarantor is a party or by
          which it is bound;

               (iii)     no Default or Event of Default shall have occurred and
          be continuing on the date of such deposit;

               (iv) the Company has delivered to the Trustee an Opinion of
          Counsel to the effect that (A) the creation of the defeasance trust
          does not violate the Investment Company Act of 1940, (B) the Holders
          have a valid first-priority security interest in the trust funds, (C)
          the Holders will not recognize income, gain or loss for federal income
          tax purposes as a result of such deposit and the defeasance of the
          obligations referred to in the first paragraph of this Section 8.03
          and will be subject to federal income tax on the same amount and in
          the same manner and at the same times as would have been the case if
          such deposit and defeasance had not occurred and (D) after the passage
          of 123 days following the deposit (except, with respect to any trust
          funds for the account of any Holder who may be deemed to be an
          "insider" for purposes of the United States Bankruptcy Code, after one
          year following the deposit), the trust funds will not be subject to
          the effect of Section 547 of the United States Bankruptcy Code or
          Section 15 of the New York Debtor and Creditor Law in a case commenced
          by or against the Company or the Guarantor under either such statute,
          and either (1) the trust funds will no longer remain the property of
          the Company or the Guarantor (and therefore will not be subject to the
          effect of any applicable bankruptcy, insolvency, reorganization or
          similar laws affecting creditors' rights generally) or (2) if a court
          were to rule under any such law in any case or proceeding that the
          trust funds remained property of the Company or the Guarantor
          (x) assuming such trust funds remained in the possession of the
          Trustee prior to such court ruling to the extent not paid to the
          Holders, the Trustee will hold, for the benefit of the Holders, a
          valid and perfected security interest in such trust funds that is not
          avoidable in bankruptcy or otherwise (except for the effect of Section
          552(b) of the United States Bankruptcy Code on interest on the trust
          funds accruing after the commencement of a case under such statute),
          (y) the Holders will be entitled to receive adequate protection of
          their interests in such trust funds if such trust funds are used in
          such case or proceeding and (z) no property, rights in property or
          other interests granted to the Trustee or the Holders in exchange for,
          or with respect to, such trust funds will be subject to any prior
          rights of holders of other Indebtedness of the Company or the
          Guarantor or any of its Subsidiaries;

               (v)  if the Securities are then listed on a national securities
          exchange, the Company shall have delivered to the Trustee an Opinion
          of Counsel to the effect that such deposit defeasance and discharge
          will not cause the Securities to be delisted; and

               (vi) the Company has delivered to the Trustee an Officers'
          Certificate and an Opinion of Counsel, in each case stating that all
          conditions precedent provided for herein relating to the defeasance
          contemplated by this Section 8.03 have been complied with.

               SECTION 8.04.  Application of Trust Money.  Subject to Section 
                            --------------------------
     8.06, the Trustee or Paying Agent shall hold in trust money or U.S.
     Government Obligations deposited with it pursuant to Section 8.01, 8.02 or
     8.03, as the case may be, and shall apply the deposited money and the money
     from U.S. Government Obligations in accordance with the Securities and this
     Indenture to the payment of principal of, premium, if any, and interest on
     the Securities; but such money need not be segregated from other funds
     except to the extent required by law.

               SECTION 8.05.  Repayment to Company.  Subject to Sections 7.07, 
                            --------------------
     8.01, 8.02 and 8.03, the Trustee and the Paying Agent shall promptly pay to
     the Company upon request set forth in an Officers' Certificate any excess
     money held by them at any time and thereupon shall be relieved from all
     liability with respect to such money.  The Trustee and the Paying Agent
     shall pay to the Company upon request any money held by them for the
     payment of principal, premium, if any, or interest that remains unclaimed
     for two years; provided that the Trustee or such Paying Agent before being
     required to make any payment may cause to be published at the expense of
     the Company once in a newspaper of general circulation in the City of New
     York or mail to each Holder entitled to such money at such Holder's address
     (as set forth in the Security Register) notice that such money remains
     unclaimed and that after a date specified therein (which shall be at least
     30 days from the date of such publication or mailing) any unclaimed balance
     of such money then remaining will be repaid to the Company.  After payment
     to the Company, Holders entitled to such money must look to the Company for
     payment as general creditors unless an applicable law designates another
     Person, and all liability of the Trustee and such Paying Agent with respect
     to such money shall cease.

               SECTION 8.06.  Reinstatement.  If the Trustee or Paying Agent is
                            -------------
     unable to apply any money or U.S. Government Obligations in accordance with
     Section 8.01, 8.02 or 8.03, as the case may be, by reason of any legal
     proceeding or by reason of any order or judgment of any court or
     governmental authority enjoining, restraining or otherwise prohibiting such
     application, the Company's and the Guarantor's obligations under this
     Indenture and the Securities shall be revived and reinstated as though no
     deposit had occurred pursuant to Section 8.01, 8.02 or 8.03, as the case
     may be, until such time as the Trustee or Paying Agent is permitted to
     apply all such money or U.S. Government Obligations in accordance with
     Section 8.01, 8.02 or 8.03, as the case may be; provided that, if the
     Company or the Guarantor has made any payment of principal of, premium, if
     any, or interest on any Securities because of the reinstatement of its
     obligations, the Company or the Guarantor, as the case may be, shall be
     subrogated to the rights of the Holders of such Securities to receive such
     payment from the money or U.S. Government Obligations held by the Trustee
     or Paying Agent.

               SECTION 8.07.  Insiders.  With respect to the determination of 
                            --------
     the Persons constituting beneficial owners of Securities and whether any
     such Person is an "insider" for purposes of Sections 8.02(D)(2)(y) and
     8.03(iv)(D), the Trustee may rely on an Officers' Certificate.


                                     ARTICLE NINE
                         AMENDMENTS, SUPPLEMENTS AND WAIVERS

               SECTION 9.01.  Without Consent of Holders.  The Company, the 
                            --------------------------
     Guarantor, when authorized by resolutions of their Boards of Directors, and
     the Trustee may amend or supplement this Indenture or the Securities
     without notice to or the consent of any Holder:

               (1)  to cure any ambiguity, defect or inconsistency in this
          Indenture; provided that such amendments or supplements shall not
          adversely affect the interests of the Holders in any material respect;

               (2)  to comply with Article Five;

               (3)  to comply with any requirements of the Commission in
          connection with the qualification of this Indenture under the TIA;

               (4)  to evidence and provide for the acceptance of appointment
          hereunder by a successor Trustee; or

               (5)  to make any change that, in the opinion of the Board of
          Directors of the Company evidenced by a Board Resolution, does not
          materially and adversely affect the rights of any Holder.

               SECTION 9.02.  With Consent of Holders.  Subject to Sections 6.04
                            -----------------------
     and 6.07 and without prior notice to the Holders, the Company, the
     Guarantor, when authorized by their Boards of Directors (as evidenced by a
     Board Resolution), and the Trustee may amend this Indenture and the
     Securities with the written consent of the Holders of a majority in
     principal amount at maturity of the Securities then outstanding, and the
     Holders of a majority in principal amount at maturity of the Securities
     then outstanding by written notice to the Trustee may waive future
     compliance by the Company or the Guarantor with any provision of this
     Indenture or the Securities.

               Notwithstanding the provisions of this Section 9.02, without the
     consent of each Holder affected, an amendment or waiver, including a waiver
     pursuant to Section 6.04, may not:

               (i)  change the Stated Maturity of the principal of, or any
          installment of interest on, any Security, or reduce the principal
          amount at maturity thereof or the rate of interest thereon or any
          premium payable upon the redemption thereof, or adversely affect any
          right of repayment at the option of any Holder of any Security, or the
          currency in which, any Security or any premium or the interest thereon
          is payable, or impair the right to institute suit for the enforcement
          of any such payment on or after the Stated Maturity thereof (or, in
          the case of redemption, on or after the Redemption Date);

               (ii) reduce the percentage in principal amount at maturity of
          outstanding Securities the consent of whose Holders is required for
          any such supplemental indenture, for any waiver of compliance with
          certain provisions of this Indenture or certain Defaults and their
          consequences provided for in this Indenture;

               (iii)     waive a Default in the payment of principal of,
          premium, if any, or interest on, any Security;

               (iv) release the Guarantor from its Security Guarantee; or

               (v)  modify any of the provisions of this Section 9.02, except to
          increase any such percentage or to provide that certain other
          provisions of this Indenture cannot be modified or waived without the
          consent of the Holder of each outstanding Security affected thereby.

               It shall not be necessary for the consent of the Holders under
     this Section 9.02 to approve the particular form of any proposed amendment,
     supplement or waiver, but it shall be sufficient if such consent approves
     the substance thereof.

               After an amendment, supplement or waiver under this Section 9.02
     becomes effective, the Company shall mail to the Holders affected thereby a
     notice briefly describing the amendment, supplement or waiver.  The Company
     will mail supplemental indentures to Holders upon request.  Any failure of
     the Company to mail such notice, or any defect therein, shall not, however,
     in any way impair or affect the validity of any such supplemental indenture
     or waiver.

               SECTION 9.03.  Revocation and Effect of Consent.  Until an 
                            --------------------------------
     amendment or waiver becomes effective, a consent to it by a Holder is a
     continuing consent by the Holder and every subsequent Holder of a Security
     or portion of a Security that evidences the same debt as the Security of
     the consenting Holder, even if notation of the consent is not made on any
     Security.  However, any such Holder or subsequent Holder may revoke the
     consent as to its Security or portion of its Security.  Such revocation
     shall be effective only if the Trustee receives the notice of revocation
     before the date the amendment, supplement or waiver becomes effective.  An
     amendment, supplement or waiver shall become effective on receipt by the
     Trustee of written consents from the Holders of the requisite percentage in
     principal amount at maturity of the outstanding Securities.

               The Company may, but shall not be obligated to, fix a record date
     for the purpose of determining the Holders entitled to consent to any
     amendment, supplement or waiver.  If a record date is fixed, then,
     notwithstanding the last two sentences of the immediately preceding
     paragraph, those persons who were Holders at such record date (or their
     duly designated proxies) and only those persons shall be entitled to
     consent to such amendment, supplement or waiver or to revoke any consent
     previously given, whether or not such persons continue to be Holders after
     such record date.  No such consent shall be valid or effective for more
     than 90 days after such record date.

               After an amendment, supplement or waiver becomes effective, it
     shall bind every Holder unless it is of the type described in any of
     clauses (i) through (v) of Section 9.02.  In case of an amendment or waiver
     of the type described in clauses (i) through (v) of Section 9.02, the
     amendment or waiver shall bind each Holder who has consented to it and
     every subsequent Holder of a Security that evidences the same indebtedness
     as the Security of the consenting Holder.

               SECTION 9.04.  Notation on or Exchange of Securities.  If an 
                            -------------------------------------
     amendment, supplement or waiver changes the terms of a Security, the
     Trustee may require the Holder to deliver it to the Trustee.  The Trustee
     may place an appropriate notation on the Security about the changed terms
     and return it to the Holder and the Trustee may place an appropriate
     notation on any Security thereafter authenticated.  Alternatively, if the
     Company or the Trustee so determines, the Company in exchange for the
     Security shall issue and the Trustee shall authenticate a new Security that
     reflects the changed terms.

               SECTION 9.05.  Trustee to Sign Amendments, Etc.  The Trustee 
                            -------------------------------
     shall be entitled to receive, and shall be fully protected in relying upon,
     an Opinion of Counsel stating that the execution of any amendment,
     supplement or waiver authorized pursuant to this Article Nine is authorized
     or permitted by this Indenture.  Subject to the preceding sentence, the
     Trustee shall sign such amendment, supplement or waiver if the same does
     not adversely affect the rights of the Trustee.  The Trustee may, but shall
     not be obligated to, execute any such amendment, supplement or waiver that
     affects the Trustee's own rights, duties or immunities under this Indenture
     or otherwise.

               SECTION 9.06.  Conformity with Trust Indenture Act.  Every 
                            -----------------------------------
     supplemental indenture executed pursuant to this Article Nine shall conform
     to the requirements of the TIA as then in effect.


                                     ARTICLE TEN
                               GUARANTEE OF SECURITIES

               SECTION 10.01.  Security Guarantee.  Subject to the provisions of
                             ------------------
     this Article Ten, the Guarantor hereby fully, unconditionally and
     irrevocably guarantees to each Holder and to the Trustee on behalf of the
     Holders:  (i) the due and punctual payment of the principal of, premium, if
     any, on and interest on each Security, when and as the same shall become
     due and payable, whether at maturity, by acceleration or otherwise, the due
     and punctual payment of interest on the overdue principal of and interest,
     if any, on the Securities, to the extent lawful, and the due and punctual
     performance of all other obligations of the Company to the Holders or the
     Trustee, all in accordance with the terms of such Security and this
     Indenture and (ii) in the case of any extension of time of payment or
     renewal of any Securities or any of such other obligations, that the same
     will be promptly paid in full when due or performed in accordance with the
     terms of the extension or renewal, at Stated Maturity, by acceleration or
     otherwise.  The Guarantor hereby waives diligence, presentment, demand of
     payment, filing of claims with a court in the event of merger or bankruptcy
     of the Company, any right to require a proceeding first against the
     Company, the benefit of discussion, protest or notice with respect to any
     such Security or the debt evidenced thereby and all demands whatsoever, and
     covenants that this Security Guarantee will not be discharged as to any
     such Security except by payment in full of the principal thereof and
     interest thereon and as provided in Section 8.01 and Section 8.02 (subject
     to Section 8.06).  The maturity of the obligations guaranteed hereby may be
     accelerated as provided in Article Six for the purposes of this Article
     Ten.  In the event of any declaration of acceleration of such obligations
     as provided in Article Six, such obligations (whether or not due and
     payable) shall forthwith become due and payable by the Guarantor for the
     purpose of this Article Ten.  In addition, without limiting the foregoing
     provisions, upon the effectiveness of an acceleration under Article Six,
     the Trustee shall promptly make a demand for payment on the Securities
     under the Security Guarantee provided for in this Article Ten.

               If the Trustee or the Holder of any Security is required by any
     court or otherwise to return to the Company or the Guarantor, or any
     custodian, receiver, liquidator, trustee, sequestrator or other similar
     official acting in relation to the Company or the Guarantor, any amount
     paid to the Trustee or such Holder in respect of a Security, this Security
     Guarantee, to the extent theretofore discharged, shall be reinstated in
     full force and effect.  The Guarantor further agrees, to the fullest extent
     that it may lawfully do so, that, as between it, on the one hand, and the
     Holders and the Trustee, on the other hand, the maturity of the obligations
     guaranteed hereby may be accelerated as provided in Article Six hereof for
     the purposes of this Security Guarantee, notwithstanding any stay,
     injunction or other prohibition extant under any applicable bankruptcy law
     preventing such acceleration in respect of the obligations Guaranteed
     hereby.

               The Guarantor hereby irrevocably waives any claim or other rights
     which it may now or hereafter acquire against the Company that arise from
     the existence, payment, performance or enforcement of its obligations under
     this Security Guarantee and this Indenture, including, without limitation,
     any right of subrogation, reimbursement, exoneration, contribution,
     indemnification, any right to participate in any claim or remedy of the
     Holders against the Company or any collateral which any such Holder or the
     Trustee on behalf of such Holder hereafter acquires, whether or not such
     claim, remedy or right arises in equity, or under contract, statute or
     common law, including, without limitation, the right to take or receive
     from the Company, directly or indirectly, in cash or other property or by
     set-off or in any other manner, payment or security on account of such
     claim or other rights.  If any amount shall be paid to the Guarantor in
     violation of the preceding sentence and the principal of, premium, if any,
     and accrued interest on the Securities shall not have been paid in full,
     such amount shall be deemed to have been paid to the Guarantor for the
     benefit of, and held in trust for the benefit of, the Holders, and shall
     forthwith be paid to the Trustee for the benefit of the Holders to be
     credited and applied upon the principal of, premium, if any, and accrued
     interest on the Securities.  The Guarantor acknowledges that it will
     receive direct and indirect benefits from the issuance of the Securities
     pursuant to this Indenture and that the waivers set forth in this Section
     10.01 are knowingly made in contemplation of such benefits.

               The Security Guarantee set forth in this Section 10.01 shall not
     be valid or become obligatory for any purpose with respect to a Security
     until the certificate of authentication on such Security shall have been
     signed by or on behalf of the Trustee.

               SECTION 10.02.  Obligations Unconditional.  Subject to Section 
                             -------------------------
     10.05, nothing contained in this Article Ten or elsewhere in this Indenture
     or in the Securities is intended to or shall impair, as among the Guarantor
     and the holders of the Securities, the obligation of the Guarantor, which
     is absolute and unconditional, upon failure by the Company, to pay to the
     holders of the Securities the principal of, premium, if any, and interest
     on the Securities as and when the same shall become due and payable in
     accordance with their terms, or is intended to or shall affect the relative
     rights of the holders of the Securities and creditors of the Guarantor, nor
     shall anything herein or therein prevent the holder of any Security or the
     Trustee on their behalf from exercising all remedies otherwise permitted by
     applicable law upon default under this Indenture.

               Without limiting the foregoing, nothing contained in this Article
     Ten will restrict the right of the Trustee or the holders of the Securities
     to take any action to declare the Security Guarantee to be due and payable
     prior to the Stated Maturity of the Securities pursuant to Section 6.02 or
     to pursue any rights or remedies hereunder.

               SECTION 10.03.  Notice to Trustee.  The Guarantor shall give
                             -----------------
     prompt written notice to the Trustee of any fact known to the Guarantor
     which would prohibit the making of any payment to or by the Trustee in
     respect of the Security Guarantee pursuant to the provisions of this
     Article Ten.

               SECTION 10.04.  This Article Not to Prevent Events of Default.  
                             ---------------------------------------------
     The failure to make a payment on account of principal of, premium, if any,
     or interest on the Securities by reason of any provision of this Article
     will not be construed as preventing the occurrence of an Event of Default.

               SECTION 10.05.  Net Worth Limitation.  Notwithstanding any other
                             --------------------
     provision of this Indenture or the Securities, the Security Guarantee shall
     not be enforceable against the Guarantor in an amount in excess of the net
     worth of the Guarantor at the time that determination of such net worth is,
     under applicable law, relevant to the enforceability of the Security
     Guarantee.  Such net worth shall include any claim of the Guarantor against
     the Company for reimbursement and any claim against any grantor of a
     Subsidiary Guarantee for contribution.


                                    ARTICLE ELEVEN
                                    MISCELLANEOUS

               SECTION 11.01.  Trust Indenture Act of 1939.  Prior to the 
                             ---------------------------
     effectiveness of the Registration Statement, this Indenture shall
     incorporate and be governed by the provisions of the TIA that are required
     to be part of and to govern indentures qualified under the TIA.  After the
     effectiveness of the Registration Statement, this Indenture shall be
     subject to the provisions of the TIA that are required to be a part of this
     Indenture and shall, to the extent applicable, be governed by such
     provisions.

               SECTION 11.02.  Notices.  Any notice or communication shall be 
                             -------
     sufficiently given if in writing and delivered in person or mailed by first
     class mail addressed as follows:

               if to the Company:
               -----------------

                    ICG Holdings, Inc.
                    9605 East Maroon Circle
                    P.O. Box 6742
                    Englewood, Colorado  80155-6742
                    Attention:  President

               if to the Guarantor:
               -------------------

                    ICG Communications, Inc.
                    9605 East Maroon Circle
                    P.O. Box 6742
                    Englewood, Colorado  80155-6742
                    Attention:  President

               if to the Trustee:
               -----------------

                    Norwest Bank Colorado, National Association
                    1740 Broadway
                    Denver, Colorado  80274-8693
                    Attention:  Corporate Trust and Escrow Services

               The Company, the Guarantor or the Trustee by notice to the other
     may designate additional or different addresses for subsequent notices or
     communications.

               Any notice or communication mailed to a Holder shall be mailed to
     him at his address as it appears on the Security Register by first class
     mail and shall be sufficiently given to him if so mailed within the time
     prescribed.  Copies of any such communication or notice to a Holder shall
     also be mailed to the Trustee and each Agent at the same time.

               Failure to mail a notice or communication to a Holder or any
     defect in it shall not affect its sufficiency with respect to other
     Holders.  Except for a notice to the Trustee, which is deemed given only
     when received, and except as otherwise provided in this Indenture, if a
     notice or communication is mailed in the manner provided in this Section
     11.02, it is duly given, whether or not the addressee receives it.

               Where this Indenture provides for notice in any manner, such
     notice may be waived in writing by the Person entitled to receive such
     notice, either before or after the event, and such waiver shall be the
     equivalent of such notice.  Waivers of notice by Holders shall be filed
     with the Trustee, but such filing shall not be a condition precedent to the
     validity of any action taken in reliance upon such waiver.

               In case by reason of the suspension of regular mail service or by
     reason of any other cause it shall be impracticable to give such notice by
     mail, then such notification as shall be made with the approval of the
     Trustee shall constitute a sufficient notification for every purpose
     hereunder.

               SECTION 11.03.  Certificate and Opinion as to Conditions 
                             -----------------------------------------
     Precedent.  Upon any request or application by the Company or the Guarantor
     ---------
     to the Trustee to take any action under this Indenture, the Company or the
     Guarantor shall furnish to the Trustee:

               (i)  an Officers' Certificate stating that, in the opinion of the
          signers, all conditions precedent, if any, provided for in this
          Indenture relating to the proposed action have been complied with; and

               (ii) an Opinion of Counsel stating that, in the opinion of such
          Counsel, all such conditions precedent have been complied with.

               SECTION 11.04.  Statements Required in Certificate or Opinion.  
                             ---------------------------------------------
     Each certificate or opinion with respect to compliance with a condition or
     covenant provided for in this Indenture shall include:

               (i)  a statement that each person signing such certificate or
          opinion has read such covenant or condition and the definitions herein
          relating thereto;

               (ii) a brief statement as to the nature and scope of the
          examination or investigation upon which the statement or opinion
          contained in such certificate or opinion is based;

               (iii)     a statement that, in the opinion of each such person,
          he has made such examination or investigation as is necessary to
          enable him to express an informed opinion as to whether or not such
          covenant or condition has been complied with; and

               (iv) a statement as to whether or not, in the opinion of each
          such person, such condition or covenant has been complied with;
          provided, however, that, with respect to matters of fact, an Opinion
          of Counsel may rely on an Officers' Certificate or certificates of
          public officials.

               SECTION 11.05.  Rules by Trustee, Paying Agent or Registrar.  The
                             -------------------------------------------
     Trustee may make reasonable rules for action by or at a meeting of Holders.
     The Paying Agent or Registrar may make reasonable rules for its functions.

               SECTION 11.06.  Payment Date Other Than a Business Day.  If an 
                             --------------------------------------
     Interest Payment Date, Redemption Date, Change of Control Payment Date,
     Excess Proceeds Payment Date, Stated Maturity or date of maturity of any
     Security shall not be a Business Day, then payment of principal of,
     premium, if any, or interest on such Security, as the case may be, need not
     be made on such date, but may be made on the next succeeding Business Day
     with the same force and effect as if made on the Interest Payment Date,
     Change of Control Payment Date, Excess Proceeds Payment Date, or Redemption
     Date, or at the Stated Maturity or date of maturity of such Security;
     provided that no interest shall accrue for the period from and after such
     Interest Payment Date, Change of Control Payment Date, Excess Proceeds
     Payment Date, Redemption Date, Stated Maturity or date of maturity, as the
     case may be.

               SECTION 11.07.  Governing Law; Submission to Jurisdiction.  The 
                             -----------------------------------------
     laws of the State of New York applicable to contracts to be performed
     entirely in that state shall govern this Indenture and the Securities. 
     Each of the Guarantor and the Company agrees to submit to the jurisdiction
     of any federal or state court located in the City of New York in any suit,
     action or proceeding with respect to this Indenture or the Securities and
     for actions brought under the U.S. federal or state securities laws brought
     in any such court.

               SECTION 11.08.  No Adverse Interpretation of Other Agreements.  
                             ---------------------------------------------
     This Indenture may not be used to interpret another indenture, loan or debt
     agreement of the Company, the Guarantor or any Subsidiary of the Guarantor.
     Any such indenture, loan or debt agreement may not be used to interpret
     this Indenture.

               SECTION 11.09.  No Recourse Against Others.  No recourse for the 
                             --------------------------
     payment of the principal of, premium, if any, or interest on any of the
     Securities, or for any claim based thereon or otherwise in respect thereof,
     and no recourse under or upon any obligation, covenant or agreement of the
     Company or the Guarantor contained in this Indenture, or in any of the
     Securities, or because of the creation of any Indebtedness represented
     thereby, shall be had against any incorporator or against any past, present
     or future partner, shareholder, other equityholder, officer, director,
     employee or controlling person, as such, of the Company or the Guarantor or
     of any successor Person, either directly or through the Company or the
     Guarantor or any successor Person, whether by virtue of any constitution,
     statute or rule of law, or by the enforcement of any assessment or penalty
     or otherwise; it being expressly understood that all such liability is
     hereby expressly waived and released as a condition of, and as a
     consideration for, the execution of this Indenture and the issue of the
     Securities.

               SECTION 11.10.  Successors.  All agreements of the Company in 
                               ----------
     this Indenture and the Securities shall bind its successors.  All
     agreements of the Guarantor in this Indenture and the Securities shall bind
     its successors.  All agreements of the Trustee in this Indenture shall bind
     its successors.

               SECTION 11.11.  Duplicate Originals.  The parties may sign any 
                             -------------------
     number of copies of this Indenture.  Each signed copy shall be an original,
     but all of them together represent the same agreement.

               SECTION 11.12.  Separability.  In case any provision in this
                             ------------
     Indenture or in the Securities shall be invalid, illegal or unenforceable,
     the validity, legality and enforceability of the remaining provisions shall
     not in any way be affected or impaired thereby.

               SECTION 11.13.  Table of Contents, Headings, Etc.  The Table of 
                             --------------------------------
     Contents, Cross-Reference Table and headings of the Articles and Sections
     of this Indenture have been inserted for convenience of reference only, are
     not to be considered a part hereof and shall in no way modify or restrict
     any of the terms and provisions hereof.


     


                                      SIGNATURES

               IN WITNESS WHEREOF, the parties hereto have caused this Indenture
     to be duly executed, all as of the date first written above.


                                         ICG HOLDINGS, INC.


                                         By:  /s/ James D. Grenfell
                                             ---------------------------------
                                            Name:  James D. Grenfell
                                            Title:  Executive Vice President,
                                                    Chief Financial Officer
                                                    and Treasurer



                                         ICG COMMUNICATIONS, INC.


                                         By: /s/ James D. Grenfell
                                            ----------------------------------
                                            Name:  James D. Grenfell
                                            Title:  Executive Vice President,
                                                    Chief Financial Officer
                                                    and Treasurer



                                         NORWEST BANK COLORADO,
                                         NATIONAL ASSOCIATION


                                         By: /s/ Amy E. Buck           
                                            --------------------------------
                                            Name:  Amy E. Buck
                                            Title: Vice President




     

                                                                    EXHIBIT A
                                                                    ---------


                                    [FACE OF NOTE]

                                  ICG HOLDINGS, INC.

                        11 5/8% Senior Discount Note Due 2007

                                                       [CUSIP] [CINS]           
                                                                    ----------


     No.                                                            $_________


               The following information is supplied for purposes of Sections
     1273 and 1275 of the Internal Revenue Code:


     Issue Date:    March 11, 1997

     Yield to maturity for period from Issue Date to March 15, 2007:  11.62%
     (rounded to two decimal places), compounded semiannually on March 15 and
     September 15 commencing March 11, 1997 (computed without giving effect to
     the additional payments of interest in the event the issuer fails to
     commence the exchange offer and fails to cause the shelf registration
     statement to be declared effective, each as referred to on the reverse
     hereof)

     Original issue discount under Section 1273 of the Internal Revenue Code
     (for each $1,000 principal amount at maturity):   $1,013.59

     Issue Price (for each $1,000 principal amount at maturity):  $567.66

               ICG HOLDINGS, INC., a Colorado corporation (the "Company", which
     term includes any successor under the Indenture hereinafter referred to),
     for value received, promises to pay to [            ], or its registered 
                                             ------------
     assigns, the principal sum of [     ] ($[     ]) on March 15, 2007.
                                    -----     -----

               Interest Payment Dates:  March 15 and September 15, commencing
     September 15, 2002.

               Regular Record Dates:  March 1 and September 1.



     



               Reference is hereby made to the further provisions of this Note
     set forth on the reverse hereof, which further provisions shall for all
     purposes have the same effect as if set forth at this place.

               IN WITNESS WHEREOF, the Company has caused this Note to be signed
     manually or by facsimile by its duly authorized officers.


     Date:  [               ]               ICG HOLDINGS, INC.
             ---------------


                                            By:

                                               --------------------------------
                                               Name:
                                               Title:

     Attest:
                Name:
                Title:



                  (Form of Trustee's Certificate of Authentication)

     This is one of the 11 5/8% Senior Discount Notes due 2007 described in the
     within-mentioned Indenture.


                                            NORWEST BANK COLORADO,
                                            NATIONAL ASSOCIATION, as Trustee


                                            By:
                                               --------------------------------
                                                     Authorized Signatory

     



                                [REVERSE SIDE OF NOTE]

                                  ICG HOLDINGS, INC.

                        11 5/8% Senior Discount Note due 2007



     1.   Principal and Interest.
           ----------------------

               The Company will pay the principal of this 11 5/8% Senior
     Discount Note due 2007 (the "Note") on March 15, 2007.

               The Company promises to pay interest on the principal amount of
     this Note on each Interest Payment Date, as set forth below, at the rate
     per annum shown above.

               Interest will be payable semiannually (to the holders of record
     of the Notes at the close of business on the March 1 or September 1
     immediately preceding the Interest Payment Date) on each Interest Payment
     Date, commencing September 15, 2002; provided that no interest shall accrue
     on the principal amount of this Note prior to March 15, 2002 and no
     interest shall be paid on this Note prior to September 15, 2002, except as
     provided in the next paragraph.

               If an exchange offer registered under the Securities Act is not
     consummated, and a shelf registration statement under the Securities Act
     with respect to resales of the Notes is not declared effective by the
     Commission, on or before September 11, 1997 in accordance with the terms of
     the Registration Rights Agreement dated March 11, 1997 among the Company,
     the Guarantor and Morgan Stanley & Co. Incorporated, interest (in addition
     to the accrual of original discount during the period ending March 15, 2002
     and in addition to the interest otherwise due on the Notes after such date)
     will accrue, at an annual rate of 0.5% of the Accreted Value on the
     preceding Semi-Annual Accrual Date on the Notes, from September 11, 1997,
     payable in cash semiannually, in arrears, on each March 15 and
     September 15, commencing March 15, 1998.  The Holder of this Note is
     entitled to the benefits of such Registration Rights Agreement.

               From and after March 15, 2002, interest on the Notes will accrue
     from the most recent date to which interest has been paid or, if no
     interest has been paid, from March 15, 2002; provided that, if there is no
     existing default in the payment of interest and this Note is authenticated
     between a Regular Record Date referred to on the face hereof and the next
     succeeding Interest Payment Date, interest shall accrue from such Interest
     Payment Date.  Interest will be computed on the basis of a 360-day year of
     twelve 30-day months.

               The Company shall pay interest on overdue principal and premium,
     if any, and interest on overdue installments of interest, to the extent
     lawful, at a rate per annum that is 2% in excess of the rate otherwise
     payable.

     2.   Method of Payment.
          -----------------

               The Company will pay principal as provided above and interest
     (except defaulted interest) on the principal amount of the Notes as
     provided above on each March 15 and September 15 to the persons who are
     Holders (as reflected in the Security Register at the close of business on
     such March 1 and September 1, immediately preceding the Interest Payment
     Date), in each case, even if the Note is cancelled on registration of
     transfer or registration of exchange after such record date; provided that,
     with respect to the payment of principal, the Company will not make payment
     to the Holder unless this Note is surrendered to a Paying Agent.

               The Company will pay principal, premium, if any, and as provided
     above, interest in money of the United States that at the time of payment
     is legal tender for payment of public and private debts.  However, the
     Company may pay principal, premium, if any, and interest by its check
     payable in such money.  It may mail an interest check to a Holder's
     registered address (as reflected in the Security Register).  If a payment
     date is a date other than a Business Day at a place of payment, payment may
     be made at that place on the next succeeding day that is a Business Day and
     no interest shall accrue for the intervening period.

     3.   Paying Agent and Registrar.
          --------------------------

               Initially, the Trustee will act as authenticating agent, Paying
     Agent and Registrar.  The Company may change any authenticating agent,
     Paying Agent or Registrar without notice.  The Company, any Subsidiary or
     any Affiliate of any of them may act as Paying Agent, Registrar or
     co-Registrar.

     4.   Indenture; Issuance of Additional Notes.
          ---------------------------------------

               The Company issued the Notes under an Indenture dated as of
     March 11, 1997 (the "Indenture"), among the Company, ICG Communications,
     Inc., a Delaware corporation (the "Guarantor"), and Norwest Bank Colorado,
     National Association, as trustee (the "Trustee").  Capitalized terms herein
     are used as defined in the Indenture unless otherwise indicated.  The terms
     of the Notes include those stated in the Indenture and those made part of
     the Indenture by reference to the Trust Indenture Act.  The Notes are
     subject to all such terms, and Holders are referred to the Indenture and
     the Trust Indenture Act for a statement of all such terms.  To the extent
     permitted by applicable law, in the event of any inconsistency between the
     terms of this Note and the terms of the Indenture, the terms of the
     Indenture shall control.

               The Notes are general unsecured obligations of the Company.  The
     Indenture provides for an initial original issuance of an aggregate
     principal amount at maturity of Notes  of $176,000,000, plus any Exchange
     Securities that may be issued pursuant to the Registration Rights
     Agreement, and, subject to Article Four of the Indenture, the issuance from
     time to time of additional Notes under the Indenture.

     5.   Redemption.
          ----------

               The Notes will be redeemable, at the Company's option, in whole
     or in part, at any time and from time to time on or after March 15, 2002
     and prior to maturity, upon not less than 30 nor more than 60 days' prior
     notice mailed by first-class mail to each Holder's last address as it
     appears in the Security Register, at the following Redemption Prices
     (expressed in percentages of their principal amount at maturity), plus
     accrued and unpaid interest, if any, to the Redemption Date (subject to the
     right of Holders of record on the relevant Regular Record Date that is on
     or prior to the Redemption Date to receive interest due on an Interest
     Payment Date that is on or prior to the Redemption Date) if redeemed during
     the 12-month period commencing on March 15 of the applicable year set forth
     below:

                                             Redemption
                    Year                         Price    
                    ----                     -------------
                    2002                     105.81250% 
                    2003                     102.90625
                    2004 and thereafter      100.00000

               In addition, at any time on or prior to March 15, 2000, the
     Company may, at its option from time to time, redeem Securities having an
     aggregate principal amount of up to 35% of the aggregate principal amount
     of all Securities issued, at a redemption price equal to 111 5/8% of the
     Accreted Value thereof on the Redemption Date, with proceeds of one or more
     Public Equity Offerings of Common Stock of (A) the Guarantor or (B) the
     Company, provided that (i) with respect to a Public Equity Offering
     referred to in clause (A) above, cash proceeds of such Public Equity
     Offering in an amount sufficient to effect the redemption of Securities to
     be so redeemed are contributed by the Guarantor to the Company prior to
     such redemption and used by the Company to effect such redemption and
     (ii) such redemption occurs within 180 days after consummation of such
     Public Equity Offering.

     6.   Notice of Redemption.
          --------------------

               Notice of any optional redemption will be mailed at least 30 days
     but not more than 60 days before the Redemption Date to each Holder of
     Notes to be redeemed at his last address as it appears in the Security
     Register.  Notes in original denominations larger than $1,000 may be
     redeemed in part.  On and after the Redemption Date, interest ceases to
     accrue on Notes or portions of Notes called for redemption, unless the
     Company defaults in the payment of the Redemption Price.

     7.   Repurchase upon Change in Control.
          ---------------------------------

               Upon the occurrence of any Change of Control, each Holder shall
     have the right to require the repurchase of its Notes by the Company in
     cash pursuant to the offer described in the Indenture at a purchase price
     equal to 101% of the Accreted Value thereof plus accrued and unpaid
     interest, if any, to the date of purchase (the "Change of Control
     Payment").

               A notice of such Change of Control will be mailed within 30 days
     after any Change of Control occurs to each Holder at his last address as it
     appears in the Security Register.  Notes in original denominations larger
     than $1,000 may be sold to the Company in part.  On and after the date of
     the Change of Control Payment, interest ceases to accrue on Notes or
     portions of Notes surrendered for purchase by the Company, unless the
     Company defaults in the payment of the Change of Control Payment.

     8.   Denominations; Transfer; Exchange.
          ---------------------------------

               The Notes are in registered form without coupons in denominations
     of $1,000 of principal amount at maturity and multiples of $1,000 in excess
     thereof.  A Holder may register the transfer or exchange of Notes in
     accordance with the Indenture.  The Registrar may require a Holder, among
     other things, to furnish appropriate endorsements and transfer documents
     and to pay any taxes and fees required by law or permitted by the
     Indenture.  The Registrar need not register the transfer or exchange of any
     Notes selected for redemption.  Also, it need not register the transfer or
     exchange of any Notes for a period of 15 days before a selection of Notes
     to be redeemed is made.

     9.   Persons Deemed Owners.
          ---------------------

               A Holder shall be treated as the owner of a Note for all
     purposes.

     10.  Unclaimed Money.
          ---------------

               If money for the payment of principal, premium, if any, or
     interest remains unclaimed for two years, the Trustee and the Paying Agent
     will pay the money back to the Company at its request.  After that, Holders
     entitled to the money must look to the Company for payment, unless an
     abandoned property law designates another Person, and all liability of the
     Trustee and such Paying Agent with respect to such money shall cease.

     11.  Discharge Prior to Redemption or Maturity.
          -----------------------------------------

               If the Company or the Guarantor deposits with the Trustee money
     or U.S. Government Obligations sufficient to pay the then outstanding
     principal of, premium, if any, and accrued interest on the Notes (a) to
     redemption or maturity, the Company will be discharged from the Indenture
     and the Notes, except in certain circumstances for certain sections
     thereof, and (b) to the Stated Maturity, the Company and the Guarantor will
     be discharged from certain covenants set forth in the Indenture.

     12.  Amendment; Supplement; Waiver.
          -----------------------------

               Subject to certain exceptions, the Indenture or the Notes may be
     amended or supplemented with the consent of the Holders of at least a
     majority in principal amount at maturity of the Notes then outstanding, and
     any existing default or compliance with any provision may be waived with
     the consent of the Holders of at least a majority in principal amount at
     maturity of the Notes then outstanding.  Without notice to or the consent
     of any Holder, the parties thereto may amend or supplement the Indenture or
     the Notes to, among other things, cure any ambiguity, defect or
     inconsistency and make any change that does not materially and adversely
     affect the rights of any Holder.

     13.  Restrictive Covenants.
          ---------------------

               The Indenture imposes certain limitations on the ability of the
     Company and the Guarantor and its Restricted Subsidiaries, among other
     things, to Incur Indebtedness, make Restricted Payments, use the proceeds
     from Asset Sales, engage in transactions with Affiliates or, with respect
     to each of the Company and the Guarantor, merge, consolidate or transfer
     substantially all of its assets.  Within 45 days after the end of each
     fiscal quarter (90 days after the end of the last fiscal quarter of each
     year), the Company must report to the Trustee on compliance with such
     limitations.

     14.  Successor Persons.
          -----------------

               When a successor person or other entity assumes all the
     obligations of its predecessor under the Notes and the Indenture, the
     predecessor person will be released from those obligations.

     15.  Defaults and Remedies.
          ---------------------

               The following events constitute "Events of Default" under the
     Indenture:  (a) default in the payment of principal of (or premium, if any,
     on) any Note when the same becomes due and payable at maturity, upon
     acceleration, redemption or otherwise; (b) default in the payment of
     interest on any Note when the same becomes due and payable, and such
     default continues for a period of 30 days; (c) the Company or the Guarantor
     defaults in the performance of or breaches any other covenant or agreement
     of the Company or the Guarantor in the Indenture or under the Notes and
     such default or breach continues for a period of 30 consecutive days after
     written notice by the Trustee or the Holders of 25% or more in aggregate
     principal amount at maturity of the Notes; (d) there occurs with respect to
     any issue or issues of Indebtedness of the Company, the Guarantor or any
     Significant Subsidiary having an outstanding principal amount at maturity
     of $10 million or more in the aggregate for all such issues of all such
     Persons, whether such Indebtedness now exists or shall hereafter be
     created, (I) an event of default that has caused the holder thereof to
     declare such Indebtedness to be due and payable prior to its Stated
     Maturity and such Indebtedness has not been discharged in full or such
     acceleration has not been rescinded or annulled within 30 days of such
     acceleration and/or (II) the failure to make a principal payment at the
     final (but not any interim) fixed maturity and such defaulted payment shall
     not have been made, waived or extended within 30 days of such payment
     default; (e) any final judgment or order (not covered by insurance) for the
     payment of money in excess of $10 million in the aggregate for all such
     final judgments or orders against all such Persons (treating any
     deductibles, self-insurance or retention as not so covered) shall be
     rendered against the Company, the Guarantor or any Significant Subsidiary
     and shall not be paid or discharged, and there shall be any period of 30
     consecutive days following entry of the final judgment or order that causes
     the aggregate amount for all such final judgments or orders outstanding and
     not paid or discharged against all such Persons to exceed $10 million
     during which a stay of enforcement of such final judgment or order, by
     reason of a pending appeal or otherwise, shall not be in effect; (f) a
     court having jurisdiction in the premises enters a decree or order for (A)
     relief in respect of the Company, the Guarantor or any Significant
     Subsidiary in an involuntary case under any applicable bankruptcy,
     insolvency or other similar law now or hereafter in effect, (B) appointment
     of a receiver, liquidator, assignee, custodian, trustee, sequestrator or
     similar official of the Company, the Guarantor or any Significant
     Subsidiary or for all or substantially all of the property and assets of
     the Company, the Guarantor or any Significant Subsidiary or (C) the winding
     up or liquidation of the affairs of the Company, the Guarantor or any
     Significant Subsidiary and, in each case, such decree or order shall remain
     unstayed and in effect for a period of 30 consecutive days; or (g) the
     Company, the Guarantor or any Significant Subsidiary (A) commences a
     voluntary case under any applicable bankruptcy, insolvency or other similar
     law now or hereafter in effect, or consents to the entry of an order for
     relief in an involuntary case under any such law, (B) consents to the
     appointment of or taking possession by a receiver, liquidator, assignee,
     custodian, trustee, sequestrator or similar official of the Company, the
     Guarantor or any Significant Subsidiary or for all or substantially all of
     the property and assets of the Company, the Guarantor or any Significant
     Subsidiary or (C) effects any general assignment for the benefit of
     creditors.  

               If an Event of Default (other than an Event of Default specified
     in clause (f) or (g) above that occurs with respect to the Company or the
     Guarantor) occurs and is continuing under the Indenture, the Trustee or the
     Holders of at least 25% in aggregate principal amount at maturity of the
     Notes, then outstanding, by written notice to the Company (and to the
     Trustee if such notice is given by the Holders), may, and the Trustee at
     the request of such Holders shall, declare the Accreted Value of, premium,
     if any, and accrued interest, if any, on the Notes to be immediately due
     and payable.

               If an Event of Default, as defined in the Indenture, occurs and
     is continuing, the Trustee or the Holders of at least 25% in principal
     amount at maturity of the Notes may declare all the Notes to be due and
     payable.  If a bankruptcy or insolvency default with respect to the Company
     or any Restricted Subsidiary occurs and is continuing, the Notes
     automatically become due and payable.  Holders may not enforce the
     Indenture or the Notes except as provided in the Indenture.  The Trustee
     may require indemnity satisfactory to it before it enforces the Indenture
     or the Notes.  Subject to certain limitations, Holders of at least a
     majority in principal amount at maturity of the Notes then outstanding may
     direct the Trustee in its exercise of any trust or power.

     16.  Guarantee.
          ---------

               The Company's obligations under the Notes are fully and
     irrevocably guaranteed by the Guarantor.

     17.  Trustee Dealings with Company or Guarantor.
         ------------------------------------------

               The Trustee under the Indenture, in its individual or any other
     capacity, may make loans to, accept deposits from and perform services for
     the Company, the Guarantor or their Affiliates and may otherwise deal with
     the Company, the Guarantor or their Affiliates as if it were not the
     Trustee.

     18.  No Recourse Against Others.
          --------------------------

               No incorporator or any past, present or future partner,
     shareholder, other
     equity holder, officer, director, employee or controlling person as such,
     of the Company or the Guarantor or of any successor Person shall have any
     liability for any obligations of the Company or the Guarantor under the
     Notes or the Indenture or for any claim based on, in respect of or by
     reason of, such obligations or their creation.  Each Holder by accepting a
     Note waives and releases all such liability.  The waiver and release are
     part of the consideration for the issuance of the Notes.

     19.  Authentication.
          --------------

               This Note shall not be valid until the Trustee or authenticating
     agent signs the certificate of authentication on the other side of this
     Note.

     20.  Abbreviations.
          -------------

               Customary abbreviations may be used in the name of a Holder or an
     assignee, such as:  TEN COM (= tenants in common), TEN ENT (= tenants by
     the entireties), JT TEN (= joint tenants with right of survivorship and not
     as tenants in common), CUST (= Custodian) and U/G/M/A (= Uniform Gifts to
     Minors Act).

               The Company will furnish to any Holder upon written request and
     without charge a copy of the Indenture.  Requests may be made to ICG
     Holdings, Inc., 9605 East Maroon Circle, P.O. Box 6742, Englewood,
     Colorado, 80155-6742, Attention:  Chief Financial Officer.


                              [FORM OF TRANSFER NOTICE]


               FOR VALUE RECEIVED the undersigned registered holder hereby
     sell(s), assign(s) and transfer(s) unto

     Insert Taxpayer Identification No.
     ----------------------------------

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

     Please print or typewrite name and address including zip code of assignee
                                                                                
     ---------------------------------------------------------------------------
                                        
     -----------------------------------

     the within Note and all rights thereunder, hereby irrevocably constituting
     and appointing                                                             
                    ------------------------------------------------------------
             attorney to transfer said Note on the books of the Company with 
     -------
     full power of substitution in the premises.


                       [THE FOLLOWING PROVISION TO BE INCLUDED
                  ON ALL SECURITIES OTHER THAN EXCHANGE SECURITIES,
                      UNLEGENDED OFFSHORE GLOBAL SECURITIES AND
                       UNLEGENDED OFFSHORE PHYSICAL SECURITIES]

          In connection with any transfer of this Note occurring prior to the
     date which is the earlier of (i) the date of an effective Registration or
     (ii) the end of the period referred to in Rule 144(k) under the Securities
     Act, the undersigned confirms that without utilizing any general
     solicitation or general advertising that:

                                     [Check One]
                                         ---------

     [  ] (a)  this Note is being transferred in compliance with the exemption
               from registration under the Securities Act of 1933, as amended,
               provided by Rule 144A thereunder.

                                          or
                                          --

     [  ] (b)  this Note is being transferred other than in accordance with
               (a) above and documents are being furnished which comply with the
               conditions of transfer set forth in this Note and the Indenture.

     If none of the foregoing boxes is checked, the Trustee or other Registrar
     shall not be obligated to register this Note in the name of any Person
     other than the Holder hereof unless and until the conditions to any such
     transfer of registration set forth herein and in Section 2.08 of the
     Indenture shall have been satisfied.

     Date:
          ---------------------------------------------------------------------
                              NOTICE:  The signature to this assignment must
                              correspond with the name as written upon the face
                              of the within-mentioned instrument in every
                              particular, without alteration or any change
                              whatsoever.



     TO BE COMPLETED BY PURCHASER IF (a) ABOVE IS CHECKED.

          The undersigned represents and warrants that it is purchasing this
     Note for its own account or an account with respect to which it exercises
     sole investment discretion and that it and any such account is a "qualified
     institutional buyer" within the meaning of Rule 144A under the Securities
     Act of 1933, as amended, and is aware that the sale to it is being made in
     reliance on Rule 144A and acknowledges that it has received such
     information regarding the Company as the undersigned has requested pursuant
     to Rule 144A or has determined not to request such information and that it
     is aware that the transferor is relying upon the undersigned's foregoing
     representations in order to claim the exemption from registration provided
     by Rule 144A.

     Dated:
           --------------------------------------------------------------------
                                   NOTICE:  To be executed by an executive
                                   officer

     


                          OPTION OF HOLDER TO ELECT PURCHASE


               If you wish to have this Note purchased by the Company pursuant
     to Section 4.11 or Section 4.12 of the Indenture, check the Box:  [ ]

               If you wish to have a portion of this Note purchased by the
     Company pursuant to Section 4.11 or Section 4.12 of the Indenture, state
     the amount (in principal amount at maturity):  $                   .
                                                     -------------------

     Date:                      
            -----------------

     Your Signature:  
                    -----------------------------------------------------------
              (Sign exactly as your name appears on the other side of this Note)

     Signature Guarantee:  
                           ------------------------------

     



                                                                     EXHIBIT B
                                                                       ---------


                                 Form of Certificate
                                 -------------------



     Norwest Bank Colorado, N.A.                                          , 19  
                                                             ---------- --    --
     1740 Broadway
     Denver, Colorado  80274-8693
     Attention:  Corporate Trust and Escrow Services

                   Re:  ICG Holdings, Inc. (the "Company")
                        11 5/8% Senior Discount Notes
                        due 2007 (the "Securities")             
                        ----------------------------------------

     Ladies and Gentlemen:

                   This letter relates to U.S. $                principal amount
                                                ---------------
     at maturity of Securities represented by a Note (the "Legended Note") which
     bears a legend outlining restrictions upon transfer of such Legended Note. 
     Pursuant to Section 2.02 of the Indenture (the "Indenture") dated as of
     March 11, 1997 relating to the Securities, we hereby certify that we are
     (or we will hold such Securities on behalf of) a person outside the United
     States to whom the Securities could be transferred in accordance with Rule
     904 of Regulation S promulgated under the U.S. Securities Act of 1933, as
     amended.  Accordingly, you are hereby requested to exchange the legended
     certificate for an unlegended certificate representing an identical
     principal amount at maturity of Securities, all in the manner provided for
     in the Indenture.

                   You and the Company are entitled to rely upon this letter and
     are irrevocably authorized to produce this letter or a copy hereof to any
     interested party in any administrative or legal proceedings or official
     inquiry with respect to the matters covered hereby.  Terms used in this
     certificate have the meanings set forth in Regulation S.

                                        Very truly yours,

                                        [Name of Holder]



                                        By:
                                           ------------------------------------
                                                   Authorized Signature


     
                                                                     EXHIBIT C
                                                                     ---------



                         Form of Certificate to Be Delivered
                            in Connection with Transfers 
                              Pursuant to Regulation S      
                         -----------------------------------




     Norwest Bank Colorado, N.A.                                          , 19  
                                                             ---------- --    --
     1740 Broadway
     Denver, Colorado  80274-8693
     Attention:  Corporate Trust and Escrow Services

                   Re:  ICG Holdings, Inc. (the "Company")
                        11 5/8% Senior Discount Notes
                        due 2007 (the "Securities")            
                        ---------------------------------------

     Ladies and Gentlemen:

                   In connection with our proposed sale of U.S.$                
                                                                 ------------
     aggregate principal amount at maturity of the Securities, we confirm that
     such sale has been effected pursuant to and in accordance with Regulation S
     under the Securities Act of 1933, as amended, and, accordingly, we
     represent that:

                   (1)  the offer of the Securities was not made to a person in
     the United States;

                   (2)  at the time the buy order was originated, the transferee
              was outside the United States or we and any person acting on our
              behalf reasonably believed that the transferee was outside the
              United States;

                   (3)  no directed selling efforts have been made by us in the
              United States in contravention of the requirements of Rule 903(b)
              or Rule 904(b) of Regulation S, as applicable; and

                   (4)  the transaction is not part of a plan or scheme to evade
              the registration requirements of the U.S. Securities Act of 1933.

                   You and the Company are entitled to rely upon this letter and
     are irrevocably authorized to produce this letter or a copy hereof to any
     interested party in any administrative or legal proceedings or official
     inquiry with respect to the matters covered hereby.  Terms used in this
     certificate have the meanings set forth in Regulation S.

                                                Very truly yours,

                                                [Name of Transferor]


                                                By:
                                                   ----------------------------
                                                       Authorized Signature

     


                                                                    EXHIBIT D
                                                                    ---------

                              Form of Certificate to Be
                             Delivered in Connection with
                      Transfers to Non-QIB Accredited Investors
                      -----------------------------------------





     Norwest Bank Colorado, N.A.                                       , 19 
                                                           ---------- --    --
     1740 Broadway
     Denver, Colorado  80274-8693
     Attention:  Corporate Trust and Escrow Services

                   Re:  ICG Holdings, Inc. (the "Company")
                        11 5/8% Senior Discount Notes
                        due 2007 (the "Securities")            
                        ---------------------------------------

     Dear Sirs:

                   In connection with our proposed purchase of $
                                                            -----------
     aggregate principal amount of the Securities, we confirm that:

                   1.   We understand that any subsequent transfer of the
              Securities is subject to certain restrictions and conditions set
              forth in the Indenture dated as of March 11, 1997 relating to the
              Securities (the "Indenture") and the undersigned agrees to be
              bound by, and not to resell, pledge or otherwise transfer the
              Securities except in compliance with, such restrictions and
              conditions and the Securities Act of 1933, as amended (the
              "Securities Act").

                   2.   We understand that the offer and sale of the Securities
              have not been registered under the Securities Act, and that the
              Securities may not be offered or sold except as permitted in the
              following sentence.  We agree, on our own behalf and on behalf of
              any accounts for which we are acting as hereinafter stated, that
              if we should sell any Securities, we will do so only (A) to the
              Company or any subsidiary thereof, (B) in accordance with
              Rule 144A under the Securities Act to a "qualified institutional
              buyer" (as defined therein), (C) to an institutional "accredited
              investor" (as defined below) that, prior to such transfer,
              furnishes (or has furnished on its behalf by a U.S. broker-dealer)
              to you and to the Company a signed letter substantially in the
              form of this letter, (D) outside the United States in accordance
              with Rule 904 of Regulation S under the Securities Act, (E)
              pursuant to the provisions of Rule 144 under the Securities Act,
              or (F) pursuant to an effective registration statement under the
              Securities Act, and we further agree to provide to any person
              purchasing any of the Securities from us a notice advising such
              purchaser that resales of the Securities are restricted as stated
              herein.

                   3.   We understand that, on any proposed resale of any
              Securities, we will be required to furnish to you and the Company
              such certifications, legal opinions and other information as you
              and the Company may reasonably require to confirm that the
              proposed sale complies with the foregoing restrictions.  We
              further understand that the Securities purchased by us will bear a
              legend to the foregoing effect.

                   4.   We are an institutional "accredited investor" (as
              defined in Rule 501(a)(1), (2), (3) or (7) of Regulation D under
              the Securities Act) and have such knowledge and experience in
              financial and business matters as to be capable of evaluating the
              merits and risks of our investment in the Securities, and we and
              any accounts for which we are acting are each able to bear the
              economic risk of our or its investment.

                   5.   We are acquiring the Securities purchased by us for our
              own account or for one or more accounts (each of which is an
              institutional "accredited investor") as to each of which we
              exercise sole investment discretion.

                   You and the Company are entitled to rely upon this letter and
     are irrevocably authorized to produce this letter or a copy hereof to any
     interested party in any administrative or legal proceedings or official
     inquiry with respect to the matters covered hereby.

                                                Very truly yours,

                                                [Name of Transferee]


                                                By:
                                                   ----------------------------
                                                       Authorized Signature