EXHIBIT 1.1
                               25,000,000 SHARES

                       CROWN CASTLE INTERNATIONAL CORP.

                                 COMMON STOCK

                          U.S. UNDERWRITING AGREEMENT
                          ---------------------------

                                                                 August __, 1998

Lehman Brothers Inc.
Credit Suisse First Boston Corporation
Goldman, Sachs & Co.
Smith Barney Inc.
As Representatives of the several
 U.S. Underwriters named in Schedule 1,
c/o Lehman Brothers Inc.
Three World Financial Center
New York, New York 10285

Dear Sirs:

          Crown Castle International Corp., a Delaware corporation (the
"Company") and Robert A. Crown, Barbara A. Crown, Robert A. Crown and PNC Bank,
Delaware, Trustees of the Robert A. Crown Grantor Retained Annuity Trust and
Barbara A. Crown and PNC Bank, Delaware, Trustees of the Barbara A. Crown
Grantor Retained Annuity Trust (collectively, the "Crown Selling Stockholders")
propose to sell an aggregate of 25,000,000 shares (the "Firm Stock") of the
Company's Common Stock, par value $.01 per share (the "Common Stock").  Of the
25,000,000 shares of the Firm Stock, 21,250,000 are being sold by the Company
and 3,750,000 by the Crown Selling Stockholders.  It is understood that, subject
to the conditions hereinafter stated, 25,000,000 shares of Common Stock will be
sold to the several U.S. underwriters named in Schedule 1 hereto (the "U.S.
Underwriters") in connection with the offering and sale of such Common Stock in
the United States and Canada to United States and Canadian Persons (as such
terms are defined in the Agreement Between U.S. Underwriters and International
Managers) (as defined).  In addition, certain executive officers of the Company
named in Schedule 2 hereto (the "Executive Selling Stockholders"), certain non-
executive employee stockholders of the Company named in Schedule 2 hereto (the
"Employee Selling Stockholders") and certain financial sponsor stockholders,
certain other stockholders who are affiliates of such financial sponsors and
certain directors of the Company named on Schedule 2 hereto (collectively, the
"Sponsor Selling Stockholders" and, together with the Executive Selling
Stockholders and the Employee Selling Stockholders, the "Option Selling
Stockholders") propose to grant to the U.S. Underwriters named in Schedule 1
hereto (the "U.S. Underwriters") an option to purchase up to an additional
4,687,500 shares of the Common Stock on the terms and for the purposes set forth
in Section 5 (the "Option Stock").  This is to confirm the agreement concerning
the purchase by the U.S. Underwriters of the Firm Stock from the Company and the
Crown Selling Stockholders and of the Option Stock, if purchased, from the

 
Option Selling Stockholders. The Firm Stock and the Option Stock, if purchased,
are hereinafter collectively called the "Stock," and the Crown Selling
Stockholders and the Option Selling Stockholders are hereinafter collectively
referred to as the "Selling Stockholders."

          It is understood by all parties that the Company is concurrently
entering into an agreement dated the date hereof (the "International
Underwriting Agreement") providing for the sale by the Company of an aggregate
of 6,250,000 shares of Common Stock (the "International Stock") through
arrangements with certain underwriters outside the United States and Canada (the
"International Managers"), for whom Lehman Brothers International (Europe),
Credit Suisse First Boston (Europe) Limited, Goldman Sachs International and
Smith Barney Inc. are acting as lead managers.  The U.S. Underwriters and the
International Managers simultaneously are entering into an agreement between the
U.S. and international underwriting syndicates (the "Agreement Between U.S.
Underwriters and International Managers") which provides for, among other
things, the transfer of shares of Common Stock between the two syndicates.  Two
forms of prospectus are to be used in connection with the offering and sale of
shares of Common Stock contemplated by the foregoing, one relating to the Stock
and the other relating to the International Stock.  The latter form of
prospectus will be identical to the former except for certain substitute pages
as included in the registration statement and amendments thereto referred to
below.  Except as used in Sections 5, 6, 7, 16, 17 and 18 herein, and except as
the context may otherwise require, references herein to the Stock shall include
all the shares of the Common Stock which may be sold pursuant to either this
Agreement or the International Underwriting Agreement, and references herein to
any prospectus, whether in preliminary or final form, and whether as amended or
supplemented, shall include both the U.S. and the international versions
thereof.

          1.  Representations, Warranties And Agreements Of The Company.  The
Company represents, warrants and agrees that:

               (a) A registration statement on Form S-1 and any amendments
          thereto with respect the Stock has (i) been prepared by the Company in
          conformity with the requirements of the United States Securities Act
          of 1933 (the "Securities Act") and the rules and regulations (the
          "Rules and Regulations") of the United States Securities and Exchange
          Commission (the "Commission") thereunder, (ii) been filed with the
          Commission under the Securities Act and (iii) become effective under
          the Securities Act.  Copies of such registration statement and the
          amendments thereto have been delivered by the Company to you as the
          representatives (the "Representatives") of the U.S. Underwriters.  As
          used in this Agreement, "Effective Time" means the date and the time
          as of which such registration statement, or the most recent post-
          effective amendment thereto, if any, was declared effective by the
          Commission; "Effective Date" means the date of the Effective Time;
          "Preliminary Prospectus" means each prospectus included in such
          registration statement, or amendments thereto, before it became
          effective under the Securities Act and any prospectus filed with the
          Commission by the Company with the consent of the Representatives
          pursuant to Rule 424(a) of the Rules and Regulations; "Registration
          Statement" means such registration

                                       2

 
          statement, as amended at the Effective Time, including all information
          contained in the final prospectus filed with the Commission pursuant
          to Rule 424(b) of the Rules and Regulations in accordance with Section
          8 hereof and deemed to be a part of the registration statement as of
          the Effective Time pursuant to paragraph (b) of Rule 430A of the Rules
          and Regulations and including any registration statement registering
          additional shares of Common Stock filed with the Commission pursuant
          to Rule 462(b) of the Rules and Regulations; and "Prospectus" means
          such final prospectus, as first filed with the Commission pursuant to
          paragraph (1) or (4) of Rule 424(b) of the Rules and Regulations. The
          Commission has not issued any order preventing or suspending the use
          of any Preliminary Prospectus.

               (b) The Registration Statement conforms, and the Prospectus and
          any further amendments or supplements to the Registration Statement or
          the Prospectus will, when they become effective or are filed with the
          Commission, as the case may be, conform, in all respects to the
          requirements of the Securities Act and the Rules and Regulations and
          do not and will not, as of the applicable effective date (as to the
          Registration Statement and any amendment thereto) and as of the
          applicable filing date (as to the Prospectus and any amendment or
          supplement thereto) contain an untrue statement of a material fact or
          omit to state a material fact required to be stated therein or
          necessary to make the statements therein not misleading; provided that
          no representation or warranty is made as to information contained in
          or omitted from the Registration Statement or the Prospectus in
          reliance upon and in conformity with written information furnished to
          the Company through the Representatives by or on behalf of any U.S.
          Underwriter or International Manager specifically for inclusion
          therein.

               (c) The industry-related and tower-related data and estimates
          included in the Prospectus are based on or derived from sources which
          the Company believes to be reliable and accurate.

               (d) The Company is a corporation duly incorporated and validly
          existing and in good standing under the laws of Delaware with all
          requisite corporate power and authority to own, lease and operate its
          properties and to conduct its business as described in the Prospectus,
          and is duly registered and qualified to conduct its business and is in
          good standing in each jurisdiction or place where the nature of its
          properties or the conduct of its business requires such registration
          or qualification, except where the failure so to register or qualify
          or to be in good standing would not have a material adverse effect on
          the condition (financial or other), business, prospects, properties or
          results of operations of the Company, Crown Communication, Inc.
          ("CCI"), Crown Network Systems, Inc. ("Network"), Crown Mobile
          Systems, Inc. ("Mobile"), TEA Group Incorporated ("TEA"), Spectrum
          Site Management Corporation ("Spectrum"), TeleStructures, Inc.
          ("TeleStructures"), Crown Castle International Corp. de Puerto Rico
          ("CCIC

                                       3

 
          (PR)"), Crown Communication New York, Inc. ("CCNY") and Castle
          Transmission Services (Holdings) Ltd. ("CTSH"), Castle Transmission
          International, Ltd. ("CTI") and Castle Transmission (Finance) Plc
          ("CTF" and, together with CCI, Network, Mobile, TEA, Spectrum,
          TeleStructures, CCIC (PR), CCNY, CTSH, CTI and CTF, the
          "Subsidiaries") taken as a whole (a "Material Adverse Effect").

               (e) None of the subsidiaries of the Company (other than CCI and,
          following the consummation of the transactions contemplated hereby,
          CTI (collectively, the "Significant Subsidiaries")) is a "significant
          subsidiary," as such term is defined in Rule 405 of the Rules and
          Regulations.

               (f) CTI is a corporation duly incorporated and validly existing
          under the laws of the jurisdiction of its incorporation with all
          requisite corporate power and authority to own, lease and operate its
          properties and to conduct its business as described in the Prospectus,
          and is duly registered and qualified to conduct its business in each
          jurisdiction or place where the nature of its properties or the
          conduct of its business requires such registration or qualification,
          except where the failure so to register or qualify or to be in good
          standing would not have a Material Adverse Effect.

               (g) As of the First Delivery Date (as defined), the Company will
          have an authorized capitalization as set forth in the Prospectus, and
          all of the issued shares of capital stock of the Company have been
          duly and validly authorized and issued, are fully paid and non-
          assessable and conform to the description thereof contained in the
          Prospectus; and all of the issued shares of capital stock of each
          subsidiary of the Company have been duly and validly authorized and
          issued and are fully paid and non-assessable and (except for
          directors' qualifying shares and except as set forth in the
          Registration Statement (including the exhibits thereto) with respect
          to shares subject to liens under the Company's Senior Credit Facility)
          are owned directly or indirectly by the Company, free and clear of all
          liens, encumbrances, equities or claims.

               (h) The unissued shares of the Stock to be issued and sold by the
          Company to the U.S. Underwriters hereunder and to the International
          Managers under the International Underwriting Agreement have been duly
          and validly authorized and, when issued and delivered against payment
          therefor as provided herein, will be duly and validly issued, fully
          paid and non-assessable; and the Stock will conform to the description
          thereof contained in the Prospectus.

               (i) The Company has all requisite corporate power and authority
          to execute, deliver and perform its obligations under this Agreement.

                                       4

 
               (j) The application for the inclusion of the Stock on the NASDAQ
          National Market System has been approved, subject only to official
          notice of issuance and evidence of satisfactory distribution.

               (k) This Agreement has been duly authorized, executed and
          delivered by the Company, and, assuming due authorization, execution
          and delivery by the U.S. Underwriters, constitutes the valid and
          binding agreement of the Company, enforceable against the Company in
          accordance with its terms (subject to applicable bankruptcy,
          insolvency, reorganization, moratorium, fraudulent transfer and other
          similar laws affecting creditors' rights generally from time to time
          in effect and to general principles of equity, including, without
          limitation, concepts of materiality, reasonableness, good faith and
          fair dealing, regardless of whether in a proceeding in equity or at
          law).

               (l) The execution, delivery and performance of this Agreement and
          the International Underwriting Agreement by the Company and the
          consummation of the transactions contemplated hereby, and the
          transactions described in the Prospectus under the caption "The Roll-
          Up" (such transactions are herein collectively called the "Roll-Up")
          will not conflict with or result in a breach or violation of any of
          the terms or provisions of, or (with the giving of notice or the lapse
          of time or both) constitute a default under, (i) any indenture,
          mortgage, deed of trust, loan agreement or other agreement or
          instrument to which the Company or any of the Subsidiaries is a party
          or by which the Company or any of the Subsidiaries is bound or to
          which any of the properties or assets of the Company or any of the
          Subsidiaries is subject, (ii) the provisions of the charter, by-laws
          or other constitutive documents of the Company or any of the
          Subsidiaries or (iii) any statute or any order, rule or regulation of
          any court or governmental agency or body having jurisdiction over the
          Company or any of the Subsidiaries or any of their properties or
          assets, except in the cases of clause (i) or (iii), such breaches,
          violations or defaults that in the aggregate would not have a Material
          Adverse Effect; and except for (A) the registration of the Stock under
          the Securities Act and (B) such consents, approvals, authorizations,
          registrations or qualifications (1) as may be required under the
          Exchange Act and applicable state or foreign securities laws in
          connection with the purchase and distribution of the Stock by the U.S.
          Underwriters and the International Managers, (2) as may have already
          been obtained or made and (3) the failure to obtain or make would not,
          individually or in the aggregate, have a Material Adverse Effect, no
          consent, approval, authorization or order of, or filing or
          registration with, any court or governmental agency or body is
          required for the execution, delivery and performance of this Agreement
          or the International Underwriting Agreement by the Company and the
          consummation of the transactions contemplated hereby and in the Roll-
          Up.

                                       5

 
               (m) Except as described in the Prospectus, there are no
          contracts, agreements or understandings between the Company or any of
          the Subsidiaries and any person granting such person the right to
          require the Company or any of the Subsidiaries to file a registration
          statement under the Securities Act with respect to any securities of
          the Company and the Subsidiaries owned or to be owned by such person
          or to require the Company or any of the Subsidiaries to include such
          securities in the securities registered pursuant to the Registration
          Statement or in any securities being registered pursuant to any other
          registration statement filed by the Company or any of the Subsidiaries
          under the Securities Act.

               (n) Except as described in the Prospectus, the Company has not
          sold or issued any shares of Common Stock during the six-month period
          preceding the date of the Prospectus, including any sales pursuant to
          Rule 144A under, or Regulation D or Regulation S of, the Securities
          Act other than shares issued pursuant to employee benefit plans or
          other employee compensation plans or pursuant to outstanding options,
          rights or warrants.

               (o) Neither the Company nor any of its subsidiaries has
          sustained, since the date of the latest audited financial statements
          included in the Prospectus, any material loss or interference with its
          business from fire, explosion, flood or other calamity, whether or not
          covered by insurance, or from any labor dispute or court or
          governmental action, order or decree, otherwise than as set forth or
          contemplated in the Prospectus; and, since such date, except as
          described or contemplated in the Prospectus, there has not been any
          change in the capital stock or long-term debt of the Company or any of
          its subsidiaries or any adverse change, or any development involving a
          prospective adverse change, which individually or in the aggregate has
          had or would have a Material Adverse Effect.

               (p) The consolidated historical and pro forma financial
          statements, together with the related notes thereto filed as part of
          the Registration Statement or included in the Prospectus comply as to
          form in all material respects with the requirements of Regulation S-X
          under the Act applicable to registration statements on Form S-1 under
          the Act.  Such historical financial statements fairly present the
          financial position of the Company at the respective dates indicated
          and the results of operations and cash flows for the respective
          periods indicated, in each case in accordance with generally accepted
          accounting principles ("GAAP") consistently applied throughout such
          periods.  Such pro forma financial statements have been prepared on a
          basis consistent with such historical statements, except for the pro
          forma adjustments specified therein, and give effect to assumptions
          made on a reasonable basis and in good faith and present fairly the
          pro forma position, results of operations and the other information
          purported to be shown therein at the respective dates or the
          respective periods therein specified.  The other financial and
          statistical information and data filed as part of the

                                       6

 
          Registration Statement or included in the Prospectus, historical and
          pro forma, are, in all material respects, fairly presented and
          prepared on a basis consistent with such financial statements and the
          books and records of the Company.

               (q) KPMG Peat Marwick LLP, who have certified certain financial
          statements of the Company, whose report appears in the Prospectus and
          who have delivered the initial letter referred to in Section 14(k)
          hereof, are independent public accountants as required by the
          Securities Act and the Rules and Regulations during the periods
          covered by the financial statements on which they reported contained
          in the Prospectus.

               (r) The Company and each of the Subsidiaries has good and
          indefeasible title to all property (real and personal) described in
          the Prospectus as being owned by it, free and clear of all liens,
          claims, security interests or other encumbrances except such as are
          described in the Prospectus, and all the material property described
          in the Prospectus as being held under lease by the Company and any
          such Subsidiary is held by it under valid, subsisting and enforceable
          leases, with only such exceptions as would not in the aggregate have a
          Material Adverse Effect. In addition, except as described in the
          Prospectus, the consummation of the transactions contemplated by this
          Agreement and the Roll-Up will not give rise to any third party rights
          of first refusal under any agreement as to which the Company and any
          of the Subsidiaries or any of their property or assets may be subject.

               (s) The Company and each of the Significant Subsidiaries carry,
          or are covered by, insurance in such amounts and covering such risks
          as is adequate for the conduct of its businesses and the value of its
          properties and as is customary for companies engaged in similar
          businesses in similar industries.

               (t) The Company and each of the Significant Subsidiaries has such
          permits, licenses, franchises, certificates of need and other
          approvals or authorizations of any governmental or regulatory
          authority ("Permits"), including, without limitation, any permits
          required by the Federal Communications Commission ("FCC"), the Federal
          Aviation Administration ("FAA") or the Office of Telecommunications
          ("OFTEL"), as are necessary under applicable law to own their
          respective properties and to conduct their respective businesses in
          the manner described in the Prospectus, except to the extent that the
          failure to have such Permits would not have a Material Adverse Effect.
          The Company and the Significant Subsidiaries have fulfilled and
          performed in all material respects, all their respective obligations
          with respect to the Permits, and no event has occurred which allows,
          or after notice or lapse of time would allow, revocation or
          termination thereof or results in any other material impairment of the
          rights of the holder of any such Permit, subject in each case to such
          qualification as may be set forth in the Prospectus and except to the
          extent that any such revocation or

                                       7

 
          termination would not have a Material Adverse Effect. Except as
          described in the Prospectus, none of the Permits contains any
          restriction that has not previously been satisfied and that is
          materially burdensome to the Company or any of the Significant
          Subsidiaries.

               (u) For each existing tower of the Company not yet registered
          with the FCC where registration will be required, the FCC's grant of
          an application for registration of such tower will not have a
          significant environmental effect as defined under Section 1.1307(a) of
          the FCC's rules.

               (v) The consummation of the transactions contemplated by this
          Agreement shall not cause any third party to have any rights of first
          refusal with respect to the acquisition of towers under any Material
          Agreement that has not already been described in the Prospectus as to
          which the Company and any of the Significant Subsidiaries or any of
          their property or assets may be subject.

               (w) The Company and each of the Significant Subsidiaries owns or
          possesses all patents, trademarks, trademark registration, service
          marks, service mark registrations, trade names, copyrights, licenses,
          inventions, trade secrets and rights described in the Prospectus as
          being owned by any of them or necessary for the conduct of their
          respective businesses, and neither the Company nor any of the
          Significant Subsidiaries is aware of any claim to the contrary or any
          challenge by any other person to the rights of the Company or any of
          the Significant Subsidiaries with respect to such rights that, if
          determined adversely to the Company or any such Significant
          Subsidiary, would in the aggregate have a Material Adverse Effect.

               (x) There are no legal or governmental proceedings pending or, to
          the knowledge of the Company, threatened, against the Company or any
          Subsidiary or to which any of their respective properties is subject,
          that are not disclosed in the Prospectus and which are reasonably
          likely to have a Material Adverse Effect.  The descriptions in the
          Prospectus of all agreements, contracts, indentures, leases or other
          instruments are accurate in all material respects and fairly present
          the information purported to be described therein.

               (y) Neither the Company nor any of the Subsidiaries is involved
          in any strike, job action or labor dispute with any group of
          employees, and, to the knowledge of the Company and the Subsidiaries,
          no such action or dispute is threatened.

               (z) The Company and each of the Subsidiaries are in compliance in
          all material respects with all presently applicable provisions of the
          Employee Retirement Income Security Act of 1974, as amended, including
          the regulations and published interpretations thereunder ("ERISA"); no
          "reportable event" (as defined in ERISA) has occurred with respect to
          any "pension plan" (as defined in

                                       8

 
          ERISA) for which the Company would have any liability; the Company has
          not incurred and does not expect to incur liability under (i) Title IV
          of ERISA with respect to termination of, or withdrawal from, any
          "pension plan" or (ii) Sections 412 or 4971 of the Internal Revenue
          Code of 1986, as amended, including the regulations and published
          interpretations thereunder (the "Code"); and each "pension plan" for
          which the Company would have any liability that is intended to be
          qualified under Section 401(a) of the Code is so qualified in all
          material respects and nothing has occurred, whether by action or by
          failure to act, which would cause the loss of such qualification.

               (aa) The Company and each of the Subsidiaries have filed all
          federal, state and local income and franchise tax returns required to
          be filed through the date hereof and have paid all taxes due thereon,
          and no tax deficiency has been determined adversely to the Company or
          any of the Subsidiaries nor does the Company or any of the
          Subsidiaries have any knowledge of any tax deficiency which, if
          determined adversely to the Company or any of the Subsidiaries, would
          have a Material Adverse Effect.

               (bb) Since the date as of which information is given in the
          Prospectus through the date hereof, and except as may otherwise be
          disclosed in the Prospectus, the Company has not (i) issued or granted
          any securities, (ii) incurred any liability or obligation, direct or
          contingent, or entered into any transaction, in each case not in the
          ordinary course of business which is material to the Company and its
          Subsidiaries taken as a whole or (iii) declared or paid any dividend
          on its capital stock (excluding payment in lieu of fractional shares
          upon conversion of certain senior preferred convertible stock of the
          Company).

               (cc) The Company (i) makes and keeps accurate books and records
          and (ii) maintains a system of internal accounting controls sufficient
          to provide reasonable assurance that (A) transactions are executed in
          accordance with management's authorization, (B) transactions are
          recorded as necessary to permit preparation of its financial
          statements in conformity with GAAP and to maintain accountability for
          assets, (C) access to its assets is permitted only in accordance with
          management's general or specific authorization and (D) the reported
          accountability for its assets is compared with existing assets at
          reasonable intervals and appropriate action is taken with respect to
          any differences.

               (dd) Neither the Company nor any of the Subsidiaries (i) is in
          violation of its charter or by-laws, (ii) is in default in any
          material respect, and no event has occurred which, with notice or
          lapse of time or both, would constitute such a default, in the due
          performance or observance of any term, covenant or condition contained
          in any material indenture, mortgage, deed of trust, loan agreement or
          other agreement or instrument to which it is a party or by which it is
          bound or to which any of its properties or assets is subject or (iii)
          is in violation in any

                                       9

 
          material respect of any law, ordinance, governmental rule, regulation
          or court decree to which it or its property or assets may be subject
          or has failed to obtain any material license, permit, certificate,
          franchise or other governmental authorization or permit necessary to
          the ownership of its property or to the conduct of its business.

               (ee) Neither the Company nor any of the Subsidiaries, nor any
          director, officer, agent, employee or other person associated with or
          acting on behalf of the Company or any of the Subsidiaries, has used
          any corporate funds for any unlawful contribution, gift, entertainment
          or other unlawful expense relating to political activity; made any
          direct or indirect unlawful payment to any foreign or domestic
          government official or employee from corporate funds; violated or is
          in violation of any provision of the Foreign Corrupt Practices Act of
          1977; or made any bribe, rebate, payoff, influence payment, kickback
          or other unlawful payment.

               (ff) There has been no storage, disposal, generation,
          manufacture, refinement, transportation, handling or treatment of
          toxic wastes, medical wastes, hazardous wastes or hazardous substances
          by the Company or any of the Subsidiaries (or, to the knowledge of the
          Company, any of their predecessors in interest) at, upon or from any
          of the property now or previously owned or leased by the Company or
          any of the Subsidiaries in violation of any applicable law, ordinance,
          rule, regulation, order, judgment, decree or permit or which would
          require remedial action under any applicable law, ordinance, rule,
          regulation, order, judgment, decree or permit, except for any
          violation or remedial action which would not have, or could not be
          reasonably likely to have, singularly or in the aggregate, a Material
          Adverse Effect; there has been no material spill, discharge, leak,
          emission, injection, escape, dumping or release of any kind onto such
          property or into the environment surrounding such property of any
          toxic wastes, medical wastes, solid wastes, hazardous wastes or
          hazardous substances due to or caused by the Company or any of the
          Subsidiaries or with respect to which the Company or any of the
          Subsidiaries has knowledge, except for any such spill, discharge,
          leak, emission, injection, escape, dumping or release which would not
          have or would not be reasonably likely to have, singularly or in the
          aggregate, a Material Adverse Effect; and the terms "hazardous
          wastes," "toxic wastes," "hazardous substances" and "medical wastes"
          shall have the meanings specified in any applicable local, state,
          federal and foreign laws or regulations with respect to environmental
          protection.

               (gg) Neither the Company nor any Subsidiary is an "investment
          company" within the meaning of such term under the United States
          Investment Company Act of 1940, as amended, and the rules and
          regulations of the Commission promulgated thereunder.

                                       10

 
               (hh) The Company has complied with all provisions of Section
          517.075, Florida Statutes relating to doing business with the
          Government of Cuba or with any person or affiliate located in Cuba.

          2. Representations, Warranties and Agreements of the Crown Selling
Stockholders. Each of the Crown Selling Stockholders represents, warrants and
agrees that:

               (a) Such Crown Selling Stockholder has, and immediately prior to
          the First Delivery Date (as defined in Section 7 hereof) such Crown
          Selling Stockholder will have, good and valid title to the shares of
          Stock to be sold by such Crown Selling Stockholder hereunder on such
          date, free and clear of all liens, encumbrances, equities or claims;
          and upon delivery of such shares and payment therefor pursuant hereto
          and thereto, good and valid title to such shares, free and clear of
          all liens, encumbrances, equities or claims, will pass to the several
          U.S. Underwriters.

               (b) Such Crown Selling Stockholder has placed in custody under a
          custody agreement (the "Custody Agreement") with the Company, as
          custodian (the "Custodian"), for delivery under this Agreement,
          certificates in negotiable form (with signature guaranteed by a
          commercial bank or trust company having an office or correspondent in
          the United States or a member firm of the New York or American Stock
          Exchanges) representing the shares of Stock to be sold by such Crown
          Selling Stockholder hereunder.

               (c) Such Crown Selling Stockholder has duly and irrevocably
          executed and delivered a power of attorney (the "Power of Attorney")
          appointing the Custodian and one or more other persons, as attorneys-
          in-fact, with full power of substitution, and with full authority
          (exercisable by any one or more of them) to execute and deliver this
          Agreement and to take such other action as may be necessary or
          desirable to carry out the provisions hereof on behalf of such Crown
          Selling Stockholder.

               (d) Such Crown Selling Stockholder has full right, power and
          authority to enter into this Agreement, the Power of Attorney and the
          Custody Agreement; the execution, delivery and performance of this
          Agreement, the Power of Attorney and the Custody Agreement by such
          Crown Selling Stockholder and the consummation by such Crown Selling
          Stockholder of the transactions contemplated hereby and thereby will
          not conflict with or result in a breach or violation of any of the
          terms or provisions of, or constitute a default under, any indenture,
          mortgage, deed of trust, loan agreement or other agreement or
          instrument to which such Crown Selling Stockholder is a party or by
          which such Crown Selling Stockholder is bound or to which any of the
          property or assets of such Crown Selling Stockholder is subject, nor
          will such actions result in any violation of any statute or any order,
          rule or regulation of any court or governmental agency or body having
          jurisdiction over such Crown Selling

                                       11

 
          Stockholder or the property or assets of such Crown Selling
          Stockholder; and, except for the registration of the Stock under the
          Securities Act and such consents, approvals, authorizations,
          registrations or qualifications as may be required under the Exchange
          Act and applicable state or foreign securities laws in connection with
          the purchase and distribution of the Stock by the U.S. Underwriters,
          no consent, approval, authorization or order of, or filing or
          registration with, any such court or governmental agency or body is
          required for the execution, delivery and performance of this
          Agreement, the Power of Attorney or the Custody Agreement by such
          Crown Selling Stockholder and the consummation by such Crown Selling
          Stockholder of the transactions contemplated hereby and thereby.

               (e) Such Crown Selling Stockholder has no actual knowledge (as
          defined in Section 15(g) hereof) of (i) any untrue statement or
          alleged untrue statement of a material fact contained in any
          Preliminary Prospectus, the Registration Statement or the Prospectus
          or in any amendment or supplement thereto, in each case as of its date
          or as of the First Delivery Date or (ii) the omission or alleged
          omission to state in any Preliminary Prospectus, the Registration
          Statement or the Prospectus, or in any amendment or supplement
          thereto, in each case as of its date or as of the First Delivery Date,
          any material fact required to be stated therein or necessary to make
          the statements therein not misleading.

               (f) Such Crown Selling Stockholder has not taken and will not
          take, directly or indirectly, any action which is designed to or which
          has constituted or which might reasonably be expected to cause or
          result in the stabilization or manipulation of the price of any
          security of the Company to facilitate the sale or resale of the shares
          of the Stock.

          3. Representations, Warranties and Agreements of the Executive Selling
Stockholders. Each Executive Selling Stockholder, severally and not jointly,
represents, warrants and agrees as to such Executive Selling Stockholder that:

               (a) Such Executive Selling Stockholder will have, immediately
          prior to the Second Delivery Date (as defined in Section 7 hereof),
          good and valid title to the shares of Stock to be sold by such
          Executive Selling Stockholder hereunder on such date, free and clear
          of all liens, encumbrances, equities or claims; and upon delivery of
          such shares and payment therefor pursuant hereto and thereto, good and
          valid title to such shares, free and clear of all liens, encumbrances,
          equities or claims, will pass to the several U.S. Underwriters.

               (b) Such Executive Selling Stockholder has placed in custody
          under a custody agreement (the "Custody Agreement") with the Company,
          as custodian (the "Custodian"), for delivery under this Agreement,
          certificates in negotiable form (with signature guaranteed by a
          commercial bank or trust company having an office or correspondent in
          the United States or a member firm of the New York 

                                       12

 
          or American Stock Exchanges) or an irrevocable exercise notice of
          options representing the shares of Stock to be sold by such Executive
          Selling Stockholder hereunder.

               (c) Such Executive Selling Stockholder has duly and irrevocably
          executed and delivered a power of attorney (the "Power of Attorney")
          appointing one or more persons as attorneys-in-fact, with full power
          of substitution, and with full authority (exercisable by any one or
          more of them) to execute and deliver this Agreement and to take such
          other action as may be necessary or desirable to carry out the
          provisions hereof on behalf of such Executive Selling Stockholder.

               (d) Such Executive Selling Stockholder has full right, power and
          authority to enter into this Agreement, the Power of Attorney and the
          Custody Agreement; the execution, delivery and performance of this
          Agreement, the Power of Attorney and the Custody Agreement by such
          Executive Selling Stockholder and the consummation by such Executive
          Selling Stockholder of the transactions contemplated hereby and
          thereby will not result in a material breach or violation of any of
          the terms or provisions of, or constitute a default under, any
          material indenture, mortgage, deed of trust, loan agreement or other
          similar agreement or instrument to which such Executive Selling
          Stockholder is a party or by which such Executive Selling Stockholder
          is bound or to which any of the property or assets of such Executive
          Selling Stockholder is subject, nor will such actions result in any
          material violation of any statute or any order, rule or regulation of
          any court or governmental agency or body having jurisdiction over such
          Executive Selling Stockholder or the property or assets of such
          Executive Selling Stockholder; and, except for (A) the registration of
          the Stock under the Securities Act and (B) such consents, approvals,
          authorizations, registrations or qualifications (1) as may be required
          under the Exchange Act and applicable state or foreign securities laws
          in connection with the purchase and distribution of the Stock by the
          U.S. Underwriters, (2) as may have already been obtained or made and
          (3) the failure to obtain or make would not, individually or in the
          aggregate, have a material adverse effect on such Selling
          Stockholder's ability to transfer and sell its Option Stock to the
          U.S. Underwriters, no consent, approval, authorization or order of, or
          filing or registration with, any such court or governmental agency or
          body is required for the execution, delivery and performance of this
          Agreement, the Power of Attorney or the Custody Agreement by such
          Executive Selling Stockholder and the consummation by such Executive
          Selling Stockholder of the transactions contemplated hereby and
          thereby.

               (e) Such Executive Selling Stockholder has no reason to believe
          that the representations and warranties of the Company contained in
          Section 1 hereof are not materially true and correct, is familiar with
          the Registration Statement and the Prospectus (as amended or
          supplemented) and has no knowledge of any material fact, condition or
          information not disclosed in the Registration Statement, as of

                                       13

 
          the effective date, or the Prospectus (or any amendment or supplement
          thereto), as of the applicable filing date, which has adversely
          affected or may adversely affect the business of the Company and is
          not prompted to sell shares of Common Stock by any information
          concerning the Company which is not set forth in the Registration
          Statement and the Prospectus.

               (f) Such Executive Selling Stockholder has not taken and will not
          take, directly or indirectly, any action which is designed to or which
          has constituted or which might reasonably be expected to cause or
          result in the stabilization or manipulation of the price of any shares
          of Common Stock or any security convertible into or exchangeable or
          exercisable for shares of Common Stock to facilitate the sale or
          resale of the shares of the Stock.

          4. Representations, Warranties and Agreements of the Employee Selling
Stockholders and the Sponsor Selling Stockholders. Each Employee Selling
Stockholder and each Sponsor Selling Stockholder, severally and not jointly,
represents, warrants and agrees as to such Employee Selling Stockholder or
Sponsor Selling Stockholder, as the case may be, that:

               (a) Such Selling Stockholder has, and immediately prior to the
          Second Delivery Date (as defined in Section 7 hereof) such Selling
          Stockholder will have, good and valid title to the shares of Stock to
          be sold by such Selling Stockholder hereunder on such date, free and
          clear of all liens, encumbrances, equities or claims; and upon
          delivery of such shares and payment therefor pursuant hereto and
          thereto, good and valid title to such shares, free and clear of all
          liens, encumbrances, equities or claims, will pass to the several U.S.
          Underwriters.

               (b) Such Selling Stockholder has placed in custody under a
          custody agreement (the "Custody Agreement") with the Company, as
          custodian (the "Custodian"), for delivery under this Agreement,
          certificates in negotiable form (with signature guaranteed by a
          commercial bank or trust company having an office or correspondent in
          the United States or a member firm of the New York or American Stock
          Exchanges) representing the shares of Stock to be sold by such Selling
          Stockholder hereunder.

               (c) Such Selling Stockholder has duly and irrevocably executed
          and delivered a power of attorney (the "Power of Attorney") appointing
          one or more persons as attorneys-in-fact, with full power of
          substitution, and with full authority (exercisable by any one or more
          of them) to execute and deliver this Agreement and to take such other
          action as may be necessary or desirable to carry out the provisions
          hereof on behalf of such Selling Stockholder.

               (d) Such Selling Stockholder has full right, power and authority
          to enter into this Agreement, the Power of Attorney and the Custody
          Agreement; the execution, delivery and performance of this Agreement,
          the Power of Attorney and the Custody Agreement by such Selling
          Stockholder and the consummation 

                                       14

 
          by such Selling Stockholder of the transactions contemplated hereby
          and thereby will not result in a material breach or violation of any
          of the terms or provisions of, or constitute a default under, any
          material indenture, mortgage, deed of trust, loan agreement or other
          similar agreement or instrument to which such Selling Stockholder is a
          party or by which such Selling Stockholder is bound or to which any of
          the property or assets of such Selling Stockholder is subject, nor
          will such actions result in any material violation of any statute or
          any order, rule or regulation of any court or governmental agency or
          body having jurisdiction over such Selling Stockholder or the property
          or assets of such Selling Stockholder; and, except for (A) the
          registration of the Stock under the Securities Act and (B) such
          consents, approvals, authorizations, registrations or qualifications
          (1) as may be required under the Exchange Act and applicable state or
          foreign securities laws in connection with the purchase and
          distribution of the Stock by the U.S. Underwriters, (2) as may have
          already been obtained or made and (3) the failure to obtain or make
          would not, individually or in the aggregate, have a material adverse
          effect on such Selling Stockholder's ability to transfer and sell its
          Option Stock to the U.S. Underwriters, no consent, approval,
          authorization or order of, or filing or registration with, any such
          court or governmental agency or body is required for the execution,
          delivery and performance of this Agreement, the Power of Attorney or
          the Custody Agreement by such Selling Stockholder and the consummation
          by such Selling Stockholder of the transactions contemplated hereby
          and thereby.

               (e) Such Selling Stockholder has not taken and will not take,
          directly or indirectly, any action which is designed to or which has
          constituted or which might reasonably be expected to cause or result
          in the stabilization or manipulation of the price of any shares of
          Common Stock or any security convertible into or exchangeable or
          exercisable for shares of Common Stock to facilitate the sale or
          resale of the shares of the Stock.

          5.   Purchase of the Stock by the U.S. Underwriters.  On the basis of
the representations and warranties contained in, and subject to the terms and
conditions of, this Agreement, the Company agrees to sell 21,250,000 shares of
the Firm Stock and the Crown Selling Stockholders hereby agree to sell an
aggregate of 3,750,000 shares of the Firm Stock (as allocated among the Crown
Selling Stockholders pursuant to Schedule 2 hereto) to the several U.S.
Underwriters and each U.S. Underwriter, severally and not jointly, agrees to
purchase the respective number of shares of Firm Stock set opposite that U.S.
Underwriter's name in Schedule 1 hereto at U.S. $__________ a share. Each U.S.
Underwriter shall be obligated to purchase from the Company and from each Crown
Selling Stockholder that number of shares of the Firm Stock which represents the
same proportion of the number of shares of the Firm Stock to be sold by the
Company and the Crown Selling Stockholders as the number of shares of the Firm
Stock set forth opposite the name of such U.S. Underwriter in Schedule 1
represents of the total number of shares of the Firm Stock to be purchased by
all of the U.S. Underwriters pursuant to this Agreement. The respective purchase
obligations of the U.S. Underwriters with respect to the

                                       15

 
Firm Stock shall be rounded among the U.S. Underwriters to avoid fractional
shares, as the Representatives may determine.

          In addition, the Option Selling Stockholders, severally and not
jointly, grant to the U.S. Underwriters an option to purchase up to an aggregate
of 4,687,500 shares of Option Stock (as allocated among the Option Selling
Stockholders pursuant to Schedule 2 hereto). Such option is granted solely for
the purpose of covering over-allotments in the sale of Firm Stock and is
exercisable as provided in Section 7 hereof. Shares of Option Stock shall be
purchased severally for the account of the U.S. Underwriters in proportion to
the number of shares of Firm Stock set opposite the name of such U.S.
Underwriters in Schedule 1 hereto at U.S. $__________ a share. The respective
purchase obligations of each U.S. Underwriter with respect to the Option Stock
shall be adjusted by the Representatives so that no U.S. Underwriter shall be
obligated to purchase Option Stock other than in 100 share amounts.

          The Company and the Crown Selling Stockholders shall not be obligated
to deliver any of the Stock to be delivered on the First Delivery Date (as
hereinafter defined) except upon payment for all the Stock to be purchased on
such Delivery Date as provided herein.  The Option Selling Stockholders shall
not be obligated to deliver any of the Option Stock to be delivered on the
Second Delivery Date (as hereinafter defined), except upon payment for all the
Option Stock to be purchased on such delivery date as provided herein.

          6. Offering of Stock by the U.S. Underwriters.

          Upon authorization by the Representatives of the release of the Firm
Stock, the several U.S. Underwriters propose to offer the Firm Stock for sale
upon the terms and conditions set forth in the Prospectus.  The Firm Stock is to
be offered to the public initially at U.S. $________ a share.

          Each U.S. Underwriter agrees that, except to the extent permitted by
the Agreement Between U.S. Underwriters and International Managers, it will not
offer or sell any of the Stock outside of the United States or Canada.

          7. Delivery of and Payment for the Stock.  Delivery of and payment
for the Firm Stock shall be made at the office of Cravath, Swaine & Moore, 825
Eighth Avenue, New York, NY 10019, at 10:00 A.M., New York City time, on the
third full business day following the date of this Agreement or at such other
date or place as shall be determined by agreement between the Representatives
and the Company. This date and time are sometimes referred to as the "First
Delivery Date." On the First Delivery Date, the Company and the Crown Selling
Stockholders shall deliver or cause to be delivered certificates representing
the Firm Stock to the Representatives for the account of each U.S. Underwriter
against payment to or upon the order of the Company and the Crown Selling
Stockholders of the purchase price in immediately available funds. Time shall be
of the essence, and delivery at the time and place specified pursuant to this
Agreement is a further condition of the obligation of each U.S. Underwriter
hereunder. Upon delivery, the Firm Stock shall be registered in such names and
in such denominations as the Representatives shall request in writing not less
than two full business days prior to the First

                                       16

 
Delivery Date. For the purpose of expediting the checking and packaging of the
certificates for the Firm Stock, the Company and the Crown Selling Stockholders
shall make the certificates representing the Firm Stock available for inspection
by the Representatives in New York, New York, not later than 2:00 P.M., New York
City time, on the business day prior to the First Delivery Date.

          At any time on or before the thirtieth day after the date of this
Agreement the option granted in Section 5 may be exercised by written notice
being given to the Company and to the Option Selling Stockholders by the
Representatives. Such notice shall set forth the aggregate number of shares of
Option Stock as to which the option is being exercised, the names in which the
shares of Option Stock are to be registered, the denominations in which the
shares of Option Stock are to be issued and the date and time, as determined by
the Representatives, when the shares of Option Stock are to be delivered;
provided, however, that this date and time shall not be earlier than the First
Delivery Date nor earlier than the second business day after the date on which
the option shall have been exercised nor later than the fifth business day after
the date on which the option shall have been exercised. The date and time the
shares of Option Stock are delivered are sometimes referred to as the "Second
Delivery Date" and the First Delivery Date and the Second Delivery Date are
sometimes each referred to as a "Delivery Date."

          Delivery of and payment for the Option Stock shall be made at the
place specified in the first sentence of the first paragraph of this Section 7
(or at such other place as shall be determined by agreement between the
Representatives and the Company) at 10:00 A.M., New York City time, on the
Second Delivery Date. On the Second Delivery Date, each Option Selling
Stockholder shall deliver or cause to be delivered the certificates representing
the Option Stock to be sold by such Option Selling Stockholder to the
Representatives for the account of each U.S. Underwriter against payment to or
upon the order of the Company of the purchase price in immediately available
funds. Time shall be of the essence, and delivery at the time and place
specified pursuant to this Agreement is a further condition of the obligation of
each U.S. Underwriter hereunder. Upon delivery, the Option Stock shall be
registered in such names and in such denominations as the Representatives shall
request in the aforesaid written notice. For the purpose of expediting the
checking and packaging of the certificates for the Option Stock, the Option
Selling Stockholders shall make the certificates representing the Option Stock
available for inspection by the Representatives in New York, New York, not later
than 2:00 P.M., New York City time, on the business day prior to the Second
Delivery Date.

          8.  Further Agreements of the Company.  The Company agrees:

               (a) To prepare the Prospectus in a form approved by the
          Representatives and to file such Prospectus pursuant to Rule 424(b)
          under the Securities Act not later than Commission's close of business
          on the second business day following the execution and delivery of
          this Agreement or, if applicable, such earlier time as may be required
          by Rule 430A(a)(3) under the Securities Act; to make no further
          amendment or any supplement to the Registration Statement or to the
          Prospectus 

                                       17

 
          except as permitted herein; to advise the Representatives, promptly
          after it receives notice thereof, of the time when any amendment to
          the Registration Statement has been filed or becomes effective or any
          supplement to the Prospectus or any amended Prospectus has been filed
          and to furnish the Representatives with copies thereof; to advise the
          Representatives, promptly after it receives notice thereof, of the
          issuance by the Commission of any stop order or of any order
          preventing or suspending the use of any Preliminary Prospectus or the
          Prospectus, of the suspension of the qualification of the Stock for
          offering or sale in any jurisdiction, of the initiation or threatening
          of any proceeding for any such purpose, or of any request by the
          Commission for the amending or supplementing of the Registration
          Statement or the Prospectus or for additional information; and, in the
          event of the issuance of any stop order or of any order preventing or
          suspending the use of any Preliminary Prospectus or the Prospectus or
          suspending any such qualification, to use promptly its best efforts to
          obtain its withdrawal;

               (b) To furnish promptly to each of the Representatives and to
          counsel for the U.S. Underwriters a signed copy of the Registration
          Statement as originally filed with the Commission, and each amendment
          thereto filed with the Commission, including all consents and exhibits
          filed therewith;

               (c) To deliver promptly to the Representatives such number of the
          following documents as the Representatives shall reasonably request:
          (i) conformed copies of the Registration Statement as originally filed
          with the Commission and each amendment thereto (in each case excluding
          exhibits other than this Agreement and the computation of earnings per
          share) and (ii) each Preliminary Prospectus, the Prospectus and any
          amended or supplemented Prospectus and, if the delivery of a
          prospectus is required at any time after the Effective Time in
          connection with the offering or sale of the Stock or any other
          securities relating thereto and if at such time any events shall have
          occurred as a result of which the Prospectus as then amended or
          supplemented would include an untrue statement of a material fact or
          omit to state any material fact necessary in order to make the
          statements therein, in the light of the circumstances under which they
          were made, not misleading, or, if for any other reason it shall be
          necessary to amend or supplement the Prospectus in order to comply
          with the Securities Act, to notify the Representatives and, upon their
          request, to prepare and furnish without charge to each U.S.
          Underwriter and to any dealer in securities as many copies as the
          Representatives may from time to time reasonably request of an amended
          or supplemented Prospectus which will correct such statement or
          omission or effect such compliance;

               (d) To file promptly with the Commission any amendment to the
          Registration Statement or the Prospectus or any supplement to the
          Prospectus that 

                                       18

 
          may, in the judgment of the Company or the Representatives, be
          required by the Securities Act or requested by the Commission;

               (e) Prior to filing with the Commission any amendment to the
          Registration Statement or supplement to the Prospectus or any
          Prospectus pursuant to Rule 424 of the Rules and Regulations, to
          furnish a copy thereof to the Representatives and counsel for the U.S.
          Underwriters and obtain the consent of the Representatives to the
          filing;

               (f) As soon as practicable after the Effective Date (it being
          understood that the Company shall have until at least 410 days after
          the end of the Company's current fiscal quarter), to make generally
          available to the Company's security holders and to deliver to the
          Representatives an earnings statement of the Company and its
          subsidiaries (which need not be audited) complying with Section 11(a)
          of the Securities Act and the Rules and Regulations (including, at the
          option of the Company, Rule 158);

               (g) For a period of three years following the Effective Date, to
          furnish to the Representatives copies of all materials furnished by
          the Company to its shareholders and all public reports and all reports
          and financial statements furnished by the Company to the principal
          national securities exchange upon which the Common Stock may be listed
          pursuant to requirements of or agreements with such exchange or to the
          Commission pursuant to the Exchange Act or any rule or regulation of
          the Commission thereunder;

               (h) Promptly from time to time to take such action as the
          Representatives may reasonably request to qualify the Stock for
          offering and sale under the securities laws of such jurisdictions as
          the Representatives may request and to comply with such laws so as to
          permit the continuance of sales and dealings therein in such
          jurisdictions for as long as may be necessary to complete the
          distribution of the Stock; provided that in connection therewith the
          Company shall not be required to qualify as a foreign corporation or
          to file a general consent to service of process in any jurisdiction;

               (i) For a period of 180 days from the date of the Prospectus, not
          to, directly or indirectly, offer for sale, sell or otherwise dispose
          of (or enter into any transaction or device which is designed to, or
          could be expected to, result in the disposition by any person at any
          time in the future of) any shares of Common Stock (other than the
          Stock, the International Stock and shares issued pursuant to employee
          benefit plans or other employee compensation plans existing on the
          date hereof or pursuant to currently outstanding options, warrants or
          rights), or sell or grant options, rights or warrants with respect to
          any shares of Common Stock (other than the grant of options pursuant
          to option plans existing on the date hereof), without the prior
          written consent of Lehman Brothers Inc.; to cause each person that, as
          of the date of this Agreement (i) is a recordholder of Common 

                                       19

 
          Stock or (ii) has the right to acquire shares of Common Stock upon
          conversion, reclassification, exchange or exercise of another
          security, which right will occur or may be fully vested and
          exercisable within 180 days of this Agreement (excluding the right to
          acquire shares of Common Stock pursuant to the CTSH All Employee Plan
          and the CTSH Bonus Share Plan, each as defined in the Prospectus); to
          furnish to the Representatives, prior to the First Delivery Date, a
          letter or letters, in form and substance substantially similar to
          Exhibit A attached hereto (which is substantially identical to Exhibit
          A to the International Underwriting Agreement);

               (j) Prior to filing with the Commission any reports on Form SR
          pursuant to Rule 463 of the Rules and Regulations, to furnish a copy
          thereof to the counsel for the U.S. Underwriters and receive and
          consider its comments thereon, and to deliver promptly to the
          Representatives a signed copy of each report on Form SR filed by it
          with the Commission; and

               (k) To take such steps as shall be necessary to ensure that
          neither the Company nor any subsidiary shall become an "investment
          company" within the meaning of such term under the U.S. Investment
          Company Act of 1940, as amended, and the rules and regulations of the
          Commission promulgated thereunder.

          9.  Further Agreements of the Crown Selling Stockholders.  Each Crown
Selling Stockholder agrees:

               (a) For a period of 180 days from the date of the Prospectus, not
          to, directly or indirectly, offer for sale, sell or otherwise dispose
          of (or enter into any transaction or device which is designed to, or
          could be expected to, result in the disposition by any person at any
          time in the future of) any shares of Common Stock (other than the
          Stock) without the prior written consent of Lehman Brothers Inc.;
          provided, however, that the foregoing provision shall not apply to
          transfers, without consideration, of the Common Stock or any
          securities convertible into, or exercisable or exchangeable for Common
          Stock, to immediate family members, to trusts established for the
          benefit of one or more immediate family members, or to trusts
          established for charitable purposes, provided that, in each case
          referred to in this proviso, the transferee executes and delivers to
          Lehman Brothers Inc. an agreement whereby the transferee agrees to be
          bound by all of the foregoing terms and provisions set forth in this
          Section 9(a);

               (b) That the Stock to be sold by such Crown Selling Stockholder
          hereunder which is represented by the certificates held in custody for
          such Crown Selling Stockholder is subject to the interest of the U.S.
          Underwriters, that the arrangements made by such Crown Selling
          Stockholder for such custody are to that extent irrevocable, and that
          the obligations of such Crown Selling Stockholder hereunder shall not
          be terminated by any act of such Crown Selling 

                                       20

 
          Stockholder, by operation of law, by the death or incapacity of any
          individual Crown Selling Stockholder or, in the case of a trust, by
          the death or incapacity of any executor or trustee or the termination
          of such trust, or the occurrence of any other event; and

               (c) To deliver to the Representatives prior to the First Delivery
          Date a properly completed and executed United States Treasury
          Department Form W-8 (if such Crown Selling Stockholder is a non-United
          States person or Form W-9 (if such Crown Selling Stockholder is a
          United States person).

          10.  Further Agreements of the Executive Selling Stockholders.  Each
Executive Selling Stockholder, severally and not jointly, agrees with respect
only to such Executive Selling Stockholder:

               (a) For a period of 180 days from the date of the Prospectus, not
          to, directly or indirectly, offer for sale, sell or otherwise dispose
          of (or enter into any transaction or device which is designed to, or
          could be expected to, result in the disposition by any person at any
          time in the future of) any shares of Common Stock without the prior
          written consent of Lehman Brothers, Inc.; provided, however, that on
          the Second Delivery Date each Executive Selling Stockholder may sell
          the number of shares of Common Stock listed opposite such Executive
          Selling Stockholder's name on Schedule 2 hereto to the Underwriters
          pursuant to Section 5 hereof, it being understood that such number of
          shares represents an amount not in excess of 12% of such Executive
          Selling Stockholder's beneficial ownership interest in Common Stock of
          the Company on a fully diluted basis, as of the date of the
          Prospectus, after giving effect to the conversion of all shares of the
          Company's Series A Preferred Stock, Series B Preferred Stock and
          Series C Preferred Stock into shares of Common Stock (the
          "Conversions"), the reclassification of shares of the Company's Class
          B Common Stock into shares of Common Stock (the "Reclassification")
          and the Roll-Up.

               (b) That the Stock to be sold by such Executive Selling
          Stockholder hereunder which is represented by the certificates or
          option exercise notices held in custody for such Executive Selling
          Stockholder is subject to the interest of the U.S. Underwriters, that
          the arrangements made by such Executive Selling Stockholder for such
          custody are to that extent irrevocable, and that the obligations of
          such Executive Selling Stockholder hereunder shall not be terminated
          by any act of such Executive Selling Stockholder, by operation of law,
          by the death or incapacity of such Executive Selling Stockholder or,
          in the case of a trust, by the death or incapacity of any executor or
          trustee or the termination of such trust, or the occurrence of any
          other event.

               (c) To deliver to the Representatives prior to the Second
          Delivery Date a properly completed and executed United States Treasury
          Department Form W-8 

                                       21

 
          (if such Executive Selling Stockholder is a non-United States person)
          or Form W-9 (if such Executive Selling Stockholder is a United States
          person).

          11.  Further Agreements of the Employee Selling Stockholders.  Each
Employee Selling Stockholder, severally and not jointly, agrees with respect
only to such Employee Selling Stockholder:

               (a) For a period of 180 days from the date of the Prospectus, not
          to, directly or indirectly, offer for sale, sell or otherwise dispose
          of (or enter into any transaction or device which is designed to, or
          could be expected to, result in the disposition by any person at any
          time in the future of) any shares of Common Stock without the prior
          written consent of Lehman Brothers Inc.; provided, however, that on
          the Second Delivery Date each Employee Selling Stockholder  may sell
          the number of shares of Common Stock listed opposite such Employee
          Selling Stockholder's name on Schedule 2 hereto to the U.S.
          Underwriters pursuant to Section 5 hereof, it being understood that
          such number of shares represents an amount not in excess of 12% of
          such Employee Selling Stockholder's beneficial ownership interest in
          Common Stock of the Company on a fully diluted basis as of the date of
          the Prospectus, after giving effect to the Conversions, the
          Reclassification and the Roll-Up; provided further, that to the extent
          the total number of shares listed opposite of any Employee Selling
          Stockholder's name on Schedule 2 hereto are not sold to the U.S.
          Underwriters pursuant to Section 5 hereof for any reason, such
          Employee Selling Stockholder may sell to third parties any shares that
          could have been sold but were not sold pursuant to Section 5 hereof in
          compliance with the registration requirements of the Securities Act or
          pursuant to a valid exemption therefrom.

               (b) That the Stock to be sold by such Employee Selling
          Stockholder hereunder which is represented by the certificates or
          option exercise notices held in custody for such Employee Selling
          Stockholder is subject to the interest of the U.S. Underwriters, that
          the arrangements made by such Employee Selling Stockholder for such
          custody are to that extent irrevocable, and that the obligations of
          such Employee Selling Stockholder hereunder shall not be terminated by
          any act of such Employee Selling Stockholder, by operation of law, by
          the death or incapacity of such Employee Selling Stockholder or, in
          the case of a trust, by the death or incapacity of any executor or
          trustee or the termination of such trust, or the occurrence of any
          other event.

               (c) To deliver to the Representatives prior to the Second
          Delivery Date a properly completed and executed United States Treasury
          Department Form W-8 (if such Employee Selling Stockholder is a non-
          United States person) or Form W-9 (if such Employee Selling
          Stockholder is a United States person).

                                       22

 
          12.  Further Agreements of the Sponsor Selling Stockholders.  Each
Sponsor Selling Stockholder, severally and not jointly, agrees with respect only
to such Sponsor Selling Stockholder:

               (a) For a period of 180 days from the date of the Prospectus, not
          to, directly or indirectly, offer for sale, sell or otherwise dispose
          of (or enter into any transaction or device which is designed to, or
          could be expected to, result in the disposition by any person at any
          time in the future of) any shares of Common Stock without the prior
          written consent of Lehman Brothers Inc.; provided, however, that on
          the Second Delivery Date each Sponsor Selling Stockholder  may sell
          the number of shares of Common Stock listed opposite such Sponsor
          Selling Stockholder's name on Schedule 2 hereto to the U.S.
          Underwriters pursuant to Section 5 hereof, it being understood that
          such number of shares represents a pro rata allocation among Sponsor
          Selling Stockholders of Option Stock in an amount equal to the
          difference between the total number of Option Stock and the aggregate
          number of Option Stock sold by the Executive Selling Stockholders and
          the Employee Selling Stockholders pursuant to Section 5 hereof.

               (b) That the Stock to be sold by such Sponsor Selling Stockholder
          hereunder which is represented by the certificates held in custody for
          such Sponsor Selling Stockholder is subject to the interest of the
          U.S. Underwriters, that the arrangements made by such Sponsor Selling
          Stockholder for such custody are to that extent irrevocable, and that
          the obligations of such Sponsor Selling Stockholder hereunder shall
          not be terminated by any act of such Sponsor Selling Stockholder, by
          operation of law, by the death or incapacity of such Sponsor Selling
          Stockholder or, in the case of a trust, by the death or incapacity of
          any executor or trustee or the termination of such trust, or the
          occurrence of any other event.

               (c) To deliver to the Representatives prior to the Second
          Delivery Date a properly completed and executed United States Treasury
          Department Form W-8 (if such Sponsor Selling Stockholder is a non-
          United States person or Form W-9 (if such Sponsor Selling Stockholder
          is a United States person).

          13.  Expenses.  The Company agrees to pay (a) the costs incident to
the authorization, issuance, sale and delivery of the Stock and any taxes
payable in connection therewith; (b) the costs incident to the preparation,
printing and filing under the Securities Act of the Registration Statement and
any amendments, supplements and exhibits thereto; (c) the costs of distributing
the Registration Statement as originally filed and each amendment thereto and
any post-effective amendments thereof (including, in each case, exhibits), any
Preliminary Prospectus, the Prospectus and any amendment or supplement to the
Prospectus, all as provided in this Agreement; (d) the costs of delivering and
distributing the Custody Agreement and the Power of Attorney; (e) the filing
fees incident to securing any required review by the National Association of
Securities Dealers, Inc. of the terms of sale of the Stock; (f) any applicable
listing 

                                       23

 
or other fees; (g) the fees and expenses (not in excess, in the
aggregate, of $__________) of qualifying the Stock under the securities laws of
the several jurisdictions as provided in Section 8(h) and of preparing, printing
and distributing a Blue Sky Memorandum (including related fees and expenses of
counsel to the U.S. Underwriters); (h) all fees and expenses of an independent
underwriter; (i) all costs and expenses of the U.S. Underwriters, including the
fees and disbursements of counsel for the U.S. Underwriters, incident to the
offer and sale of shares of the Stock by the U.S. Underwriters to employees and
persons having business relationships with the Company and its subsidiaries; (k)
all fees and expenses of Hutchins, Wheeler & Dittmar, counsel to the Sponsor
Selling Stockholders, incurred in connection with the Public Offering; and (l)
all other costs and expenses incident to the performance of the obligations of
the Company and the Selling Stockholders under this Agreement; provided that,
except as provided in this Section 13 and in Section 18, the U.S. Underwriters
shall pay their own costs and expenses, including the costs and expenses of
their counsel, any transfer taxes on the Stock which they may sell and the
expenses of advertising any offering of the Stock made by the U.S. Underwriters.

          14.  Conditions of U.S. Underwriters' Obligations.  The respective
obligations of the U.S. Underwriters hereunder are subject to the accuracy, when
made and on each Delivery Date, of the representations and warranties of the
Company and the Selling Stockholders contained herein, to the performance by the
Company and the Selling Stockholders of their obligations hereunder, and to each
of the following additional terms and conditions:

               (a) The Prospectus shall have been timely filed with the
          Commission in accordance with Section 8(a); no stop order suspending
          the effectiveness of the Registration Statement or any part thereof
          shall have been issued and no proceeding for that purpose shall have
          been initiated or threatened by the Commission; and any request of the
          Commission for inclusion of additional information in the Registration
          Statement or the Prospectus or otherwise shall have been complied
          with.

               (b) No U.S. Underwriter or International Manager shall have
          discovered and disclosed to the Company on or prior to such Delivery
          Date that the Registration Statement or the Prospectus or any
          amendment or supplement thereto contains an untrue statement of a fact
          which, in the opinion of Latham & Watkins, counsel for the U.S.
          Underwriters, is material or omits to state a fact which, in the
          opinion of such counsel, is material and is required to be stated
          therein or is necessary to make the statements therein not misleading.

               (c) All corporate proceedings and other legal matters incident to
          the authorization, form, validity, execution and delivery of this
          Agreement, the International Underwriting Agreement, the Custody
          Agreement, the Power of Attorney, the Stock, the Registration
          Statement and the Prospectus, and all other legal matters relating to
          this Agreement and the transactions contemplated hereby shall be
          reasonably satisfactory in all material respects to counsel for the
          U.S. Underwriters, and the Company and the Selling Stockholders shall
          have furnished 

                                       24

 
          to such counsel all documents and information that they may reasonably
          request to enable them to pass upon such matters.

               (d) Cravath, Swaine & Moore shall have furnished to the
          Representatives its written opinion, as counsel to the Company,
          addressed to the U.S. Underwriters and dated such Delivery Date, in
          form and substance reasonably satisfactory to the Representatives, to
          the effect that:

                    (i)    Each of the Company and CCI is a corporation validly
               existing and in good standing under the laws of the state of its
               incorporation (which opinion may be based solely on a certificate
               of the Secretary of State of such state), and the Company has all
               requisite corporate power and authority to own, lease and operate
               its properties and to conduct its business as described in the
               Prospectus.  Each of the Company and CCI is duly registered and
               qualified to conduct its business and is in good standing (which
               opinion may be based solely on a certificate of the Secretary of
               State of such state), in each jurisdiction or place where, based
               on a certificate of an officer of the Company, the nature of its
               properties or the conduct of its business requires such
               registration or qualification, except where the failure so to
               register or qualify or to be in good standing would not have a
               Material Adverse Effect;

                    (ii)   The Company has an authorized capitalization as set
               forth in the Prospectus, and all of the issued shares of capital
               stock of the Company (including the shares of Stock being
               delivered on such Delivery Date) have been duly and validly
               authorized and issued, are fully paid and non-assessable and
               conform to the description thereof contained in the Prospectus;

                    (iii)  Except as described in the Prospectus, there are no
               preemptive or other rights to subscribe for or to purchase, nor
               any restriction upon the voting or transfer of, any shares of the
               Stock pursuant to the Company's charter or by-laws or any
               agreement or other instrument known to such counsel;

                    (iv)   To knowledge of such counsel, there are no legal or
               governmental proceedings pending or threatened against the
               Company or any of the Significant Subsidiaries, or to which any
               of their respective properties is subject, that are not disclosed
               in the Prospectus and which are reasonably likely to have a
               Material Adverse Effect or to materially affect the issuance of
               the shares of capital stock or the consummation of the
               transactions contemplated by this Agreement and the Roll-Up.  To
               the knowledge of such counsel, there are no agreements,
               contracts, indentures, leases or other instruments to which the
               Company or any of the Significant 

                                       25

 
               Subsidiaries is a party or to which any of their respective
               properties or assets is subject that are required to be described
               in, or filed as exhibits to, the Registration Statement and the
               Prospectus that have not been so described or filed;

                    (v)    The Registration Statement was declared effective
               under the Securities Act as of the date and time specified in
               such opinion, the Prospectus was filed with the Commission
               pursuant to the subparagraph of Rule 424(b) of the Rules and
               Regulations specified in such opinion on the date specified
               therein and no stop order suspending the effectiveness of the
               Registration Statement has been issued and, to the knowledge of
               such counsel, no proceeding for that purpose is pending or
               threatened by the Commission;

                    (vi)   The Registration Statement and the Prospectus and any
               further amendments or supplements thereto made by the Company
               prior to such Delivery Date (other than the financial statements
               and related schedules therein, as to which such counsel need
               express no opinion) comply as to form in all material respects
               with the requirements of the Securities Act and the Rules and
               Regulations;

                    (vii)  The statements contained (A) in the Prospectus under
               the captions "Description of Capital Stock", "Shares Eligible for
               Future Sale", "Certain United States Federal Tax Consequences to
               Non-United States Holders" and paragraphs 1, 2, 3, 4, 5, 6, 10,
               11, 12, 13, 14, 15, 16, 17, 18, 19, 20 and 21 under the caption
               "Underwriting" and (B) in the Registration Statement in Items 14
               and 15, in each case insofar as they are descriptions of
               contracts, agreements or other legal documents, or refer to
               statements of law or legal conclusions, are accurate in all
               material respects and present fairly the information purported to
               be described therein;

                    (viii) This Agreement and the International Underwriting
               Agreement have each been duly and validly authorized, executed
               and delivered by the Company and CCI;

                    (ix)   None of the issuance, offer or sale of the shares of
               Common Stock, the execution, delivery or performance by the
               Company of this Agreement and the International Underwriting
               Agreement, compliance by the Company with the provisions hereof
               nor consummation by the Company of the transactions contemplated
               hereby and in the Roll-Up (i) requires any consent, approval,
               authorization or other order of, or registration or filing with,
               any court, regulatory body, administrative agency or other
               governmental body, agency or official, or conflicts or will
               conflict with or constitutes or will constitute a breach of, or a
               default under, the certificate of incorporation or by-laws or
               other organizational 

                                       26

 
               documents of the Company or (ii) conflicts or will conflict with
               or constitutes or will constitute a breach of, or a default
               under, any agreement filed as an exhibit to, or incorporated by
               reference in, the Registration Statement (the "Material
               Agreements"), or violates or will violate any law, rule or
               regulation of the United States, or the State of New York or the
               General Corporation Law of the State of Delaware, or, to such
               counsel's knowledge, any order or decree of any court or
               government agency or instrumentality or will result in the
               creation or imposition of any Lien upon any property or assets of
               the Company or CCI pursuant to the terms of any agreement or
               instrument to which any of them is a party or by which any of
               them may be bound or under any to which any of their respective
               property or assets is subject, except in each case such breaches,
               conflicts or defaults that, individually or in the aggregate,
               would not have a Material Adverse Effect. For purposes of the
               foregoing opinion, such counsel may assume that any agreements
               referred to in clause (ii) above that are governed by laws other
               than the laws of the State of New York, are governed by and would
               be interpreted in accordance with the laws of the State of New
               York; and


                    (x)  The Company is not and, upon sale of the shares of
               Common Stock to be issued and sole thereby in accordance herewith
               and the application of the net proceeds to the Company of such
               sale as described in the Prospectus under the caption "Use of
               Proceeds," will not be an "investment company" within the meaning
               of the Investment Company Act of 1940, as amended.

               In addition, such counsel shall also state that such counsel has
          participated in conferences with officers of the Company and with the
          independent public accountants for the Company, concerning the
          preparation of the Registration Statement and the Prospectus, and,
          although such counsel has made certain inquiries and investigations in
          connection with the preparation of the Registration Statement and the
          Prospectus, it is not passing upon and does not assume any
          responsibility for the accuracy or completeness of the statements
          contained in the Registration Statement and the Prospectus, and has
          not made any independent check or verification thereof, except insofar
          as such statements relate to such counsel and to clause (xii) above,
          and on the basis of the foregoing such counsel's work in connection
          with this matter did not disclose any information that gave such
          counsel reason to believe that the Registration Statement and the
          Prospectus, as of its date or as of the Closing Date, included or
          includes an untrue statement of a material fact or omitted or omits to
          state a material fact necessary to make the statements therein, in the
          light of the circumstances under which they were made, not misleading
          (it being understood that such counsel need express no belief or
          opinion with respect to the financial statements and other financial
          data included therein).

                                       27

 
     The opinion of such counsel may be limited to the laws of the state of New
     York, the General Corporation Law of the state of Delaware and the Federal
     laws of the United States.

               (e) Brown, Parker & Leahy, L.L.P. shall have furnished to the
          Representatives its written opinion, as counsel to the Company,
          addressed to the U.S. Underwriters and dated such Delivery Date, in
          form and substance reasonably satisfactory to the Representatives, to
          the effect that:

                    (i)    All of the issued shares of capital stock of each
               Subsidiary of the Company have been duly and validly authorized
               and issued and are fully paid, non-assessable and (except for
               directors' qualifying shares and as described in the Prospectus
               with respect to CTI) are owned directly or indirectly by the
               Company, free and clear of all liens, encumbrances, equities or
               claims;

                    (ii)   To knowledge of such counsel, there are no legal or
               governmental proceedings pending or threatened against the
               Company or any of the Significant Subsidiaries, or to which any
               of their respective properties is subject, that are not disclosed
               in the Prospectus and which are reasonably likely to have a
               Material Adverse Effect or to materially affect the issuance of
               the shares of capital stock or the consummation of the
               transactions contemplated by this Agreement and the Roll-Up;

                    (iii)  To the knowledge of such counsel, except as described
               in the Prospectus there are no contracts, agreements or
               understandings between the Company or any of the Significant
               Subsidiaries and any person granting such person the right to
               require the Company or any of the Significant Subsidiaries to
               file a registration statement under the Securities Act with
               respect to any securities of the Company owned or to be owned by
               such person or to require the Company or any of the Significant
               Subsidiaries to include such securities in the securities
               registered pursuant to the Registration Statement or in any
               securities being registered pursuant to any other registration
               statement filed by the Company or any of the Significant
               Subsidiaries under the Securities Act; and

                    (iv)   The Senior Credit Facility has been duly and validly
               authorized, executed and delivered by CCI and CCIC (PR) and
               assuming due authorization, execution and delivery by the other
               parties thereto, constitutes the valid and binding agreement of
               CCI and CCIC (PR), enforceable against CCI and CCIC (PR) in
               accordance with its terms (subject to applicable bankruptcy,
               insolvency, reorganization, moratorium, fraudulent transfer and
               other similar laws affecting creditors' rights generally from
               time to time in effect and to general principles of equity,
               including, without limitation, concepts of materiality,
               reasonableness, 
                                     
                                      28


               good faith and fair dealing, regardless of whether in a
               proceeding in equity or at law).

          The opinion of such counsel may be limited to the laws of the state of
          Texas, the state of New York, the General Corporation Law of the state
          of Delaware and the Federal laws of the United States.

               (f) The counsel for each of the Crown Selling Stockholders shall
          have furnished to the Representatives its written opinion, as counsel
          to such Selling Stockholder, addressed to the U.S. Underwriters and
          dated the First Delivery Date, in form and substance reasonably
          satisfactory to the Representatives, to the effect that:

                   (i)     Such Selling Stockholder has full right, power and
               authority to enter into this Agreement, the Power of Attorney and
               the Custody Agreement; the execution, delivery and performance of
               this Agreement, the Power of Attorney and the Custody Agreement
               by such Selling Stockholder and the consummation by such Selling
               Stockholder of the transactions contemplated hereby and thereby
               will not conflict with or result in a breach or violation of any
               of the terms or provisions of, or constitute a default under, any
               statute, any indenture, mortgage, deed of trust, loan agreement
               or other agreement or instrument known to such counsel to which
               such Selling Stockholder is a party or by which such Selling
               Stockholder is bound or to which any of the property or assets of
               such Selling Stockholder is subject, nor will such actions result
               in any violation of any statute or any order, rule or regulation
               known to such counsel of any court or governmental agency or body
               having jurisdiction over such Selling Stockholder or the property
               or assets of such Selling Stockholder; and, except for the
               registration of the Stock under the Securities Act and such
               consents, approvals, authorizations, registrations or
               qualifications as may be required under the Exchange Act and
               applicable state or foreign securities laws in connection with
               the purchase and distribution of the Stock by the U.S.
               Underwriters and the International Managers, no consent,
               approval, authorization or order of, or filing or registration
               with, any such court or governmental agency or body is required
               for the execution, delivery and performance of this Agreement,
               the Power of Attorney or the Custody Agreement by such Selling
               Stockholder and the consummation by such Selling Stockholder of
               the transactions contemplated hereby and thereby;

                    (ii)   This Agreement has each been duly executed and
               delivered by or on behalf of such Selling Stockholder;

                    (iii)  A Power-of-Attorney and a Custody Agreement have been
               duly executed and delivered by such Selling Stockholder and
               constitute 
                                          
                                      29

 
               valid and binding agreements of such Selling Stockholder,
               enforceable in accordance with their respective terms;

                    (iv) Such Selling Stockholder has full right, power and
               authority to sell, assign, transfer and deliver the shares to be
               sold by such Selling Stockholder hereunder; and

                    (v) Upon physical delivery of the certificates representing
               the shares of Stock to be sold by such Selling Stockholder under
               this Agreement to the U.S. Underwriters in the State of New York
               with undated stock powers duly endorsed in blank, and upon
               payment therefor in accordance with the terms of this Agreement,
               the U.S. Underwriters will become the "protected purchasers" (as
               defined in Section 8-303(a) of the New York UCC) of such shares,
               free of any "adverse claim" (as defined in Section 8-102(a)(1) of
               the New York UCC), assuming that the U.S. Underwriters do not
               have notice of any adverse claim to such shares.

               In rendering such opinion, such counsel may (i) state that its
          opinion is limited to matters governed by the Federal laws of the
          United States of America, the laws of the Commonwealth of Pennsylvania
          and the General Corporation Law of the State of Delaware and that such
          counsel is not admitted in the State of New York (with all New York
          law opinions being based upon the assumption that the laws of the
          State of New York and the laws of the Commonwealth of Pennsylvania are
          identical in all material respects) and (ii) in rendering the opinions
          in Section 14(f)(i) and (iv) above, rely upon a certificate of such
          Selling Stockholder in respect of matters of fact as to ownership of
          and liens, encumbrances, equities or claims on the shares of Stock
          sold by such Selling Stockholder, provided that such counsel shall
          furnish copies thereof to the Representatives and state that they
          believe that both the U.S. Underwriters and they are justified in
          relying upon such certificate.

                   (g) The counsel for each Executive Selling Stockholder and
          each Employee Selling Stockholder shall have furnished to the
          Representatives its written opinion, as counsel to such Selling
          Stockholder, addressed to the U.S. Underwriters and dated the Second
          Delivery Date, in form and substance reasonably satisfactory to the
          Representatives, to the effect that:

                        (i)  Such Selling Stockholder has full right, power and
               authority to enter into this Agreement, the Power of Attorney and
               the Custody Agreement; the execution, delivery and performance of
               this Agreement, the Power of Attorney and the Custody Agreement
               by such Selling Stockholder and the consummation by such Selling
               Stockholder of the transactions contemplated hereby and thereby
               will not conflict with or result in a breach or violation of any
               of the terms or provisions of, or constitute a default under, any
               statute, any indenture, mortgage, deed of

                                      30

 
               trust, loan agreement or other agreement or instrument known to
               such counsel to which such Selling Stockholder is a party or by
               which such Selling Stockholder is bound or to which any of the
               property or assets of such Selling Stockholder is subject, nor
               will such actions result in any violation of any statute or any
               order, rule or regulation known to such counsel of any court or
               governmental agency or body having jurisdiction over such Selling
               Stockholder or the property or assets of such Selling
               Stockholder; and, except for the registration of the Stock under
               the Securities Act and such consents, approvals, authorizations,
               registrations or qualifications as may be required under the
               Exchange Act and applicable state or foreign securities laws in
               connection with the purchase and distribution of the Stock by the
               U.S. Underwriters, no consent, approval, authorization or order
               of, or filing or registration with, any such court or
               governmental agency or body is required for the execution,
               delivery and performance of this Agreement, the Power of Attorney
               or the Custody Agreement by such Selling Stockholder and the
               consummation by such Selling Stockholder of the transactions
               contemplated hereby and thereby;

                    (ii)      This Agreement has been duly executed and
               delivered by or on behalf of such Selling Stockholder;

                    (iii)     A Power-of-Attorney and a Custody Agreement have
               been duly executed and delivered by such Selling Stockholder and
               constitute valid and binding agreements of such Selling
               Stockholder, enforceable in accordance with their respective
               terms;

                    (iv)      Immediately prior to the Second Delivery Date,
               such Selling Stockholder had full right, power and authority to
               sell, assign, transfer and deliver such shares to be sold by such
               Selling Stockholder hereunder; and

                    (v)       Good and valid title to the shares of Stock to be
               sold by such Selling Stockholder under this Agreement, free and
               clear of all liens, encumbrances, equities or claims, has been
               transferred to each of the several U.S. Underwriters.

               In rendering such opinion, such counsel may (i) state that its
          opinion is limited to matters governed by the Federal laws of the
          United States of America, the laws of the State of Texas and the
          General Corporation Law of the State of Delaware and that such counsel
          is not admitted in the State of New York and (ii) in rendering the
          opinion in Section 14(g)(iv) above, rely upon a certificate of such
          Selling Stockholder in respect of matters of fact as to ownership of
          and liens, encumbrances, equities or claims on the shares of Stock
          sold by such Selling Stockholder, provided that such counsel shall
          furnish copies thereof to the 

                                       31

 
          Representatives and state that they believe that both the U.S.
          Underwriters and they are justified in relying upon such certificate.

               (g)  The counsel for each Sponsor Selling Stockholder shall have
          furnished to the Representatives its written opinion, as counsel to
          such Sponsor Selling Stockholder, addressed to the U.S. Underwriters
          and dated the Second Delivery Date, in form and substance reasonably
          satisfactory to the Representatives, to the effect that:

                    (i)       This Agreement has each been duly executed and
               delivered by or on behalf of such Sponsor Selling Stockholder;

                    (ii)      A Power-of-Attorney and a Custody Agreement have
               been duly executed and delivered by such Sponsor Selling
               Stockholder and constitute valid and binding agreements of such
               Sponsor Selling Stockholder, enforceable in accordance with their
               respective terms; and

                    (iii)     The delivery by each Sponsor Selling Stockholder
               to the several U.S. Underwriters of certificates for the shares
               of Common Stock being sold under this Agreement, with due
               endorsement for transfer by such Sponsor Selling Stockholder,
               against payment therefor in accordance with this Agreement, has
               transferred valid title to such shares of Stock, free and clear
               of all adverse claims, to each of the several U.S. Underwriters,
               assuming that the U.S. Underwriters are without actual notice of
               any adverse claim.

               In rendering such opinion, such counsel may (i) state that its
          opinion is limited to matters governed by the Federal laws of the
          United States of America, the laws of the Commonwealth of
          Massachusetts and the General Corporation Law of the State of Delaware
          and that such counsel is not admitted in the State of New York.


               (i)  The Representatives shall have received an opinion, dated
          the First Delivery Date, of Norton Rose, English counsel for Castle
          Transmission Services (Holdings) Ltd., substantially in the form of
          Exhibit B hereto.

               (j)  The Representatives shall have received from Latham &
          Watkins, counsel for the U.S. Underwriters, such opinion or opinions,
          dated such Delivery Date, with respect to the issuance and sale of the
          Stock, the Registration Statement, the Prospectus and other related
          matters as the Representatives may reasonably require, and the Company
          shall have furnished to such counsel such documents as they reasonably
          request for the purpose of enabling them to pass upon such matters.

                                       32

 
               (k)  At the time of execution of this Agreement, the
          Representatives shall have received from KPMG Peat Marwick LLP a
          letter, in form and substance satisfactory to the Representatives,
          addressed to the U.S. Underwriters and dated the date hereof (i)
          confirming that they are independent public accountants within the
          meaning of the Securities Act and are in compliance with the
          applicable requirements relating to the qualification of accountants
          under Rule 2-01 of Regulation S-X of the Commission, (ii) stating, as
          of the date hereof (or, with respect to matters involving changes or
          developments since the respective dates as of which specified
          financial information is given in the Prospectus, as of a date not
          more than five days prior to the date hereof), the conclusions and
          findings of such firm with respect to the financial information and
          other matters ordinarily covered by accountants' "comfort letters" to
          U.S. Underwriters in connection with registered public offerings.

               (l)  With respect to the letter of KPMG Peat Marwick LLP referred
          to in the preceding paragraph and delivered to the Representatives
          concurrently with the execution of this Agreement (the "initial
          letter"), the Company shall have furnished to the Representatives a
          letter (the "bring-down letter") of such accountants, addressed to the
          U.S. Underwriters and dated such Delivery Date (i) confirming that
          they are independent public accountants within the meaning of the
          Securities Act and are in compliance with the applicable requirements
          relating to the qualification of accountants under Rule 2-01 of
          Regulation S-X of the Commission, (ii) stating, as of the date of the
          bring-down letter (or, with respect to matters involving changes or
          developments since the respective dates as of which specified
          financial information is given in the Prospectus, as of a date not
          more than five days prior to the date of the bring-down letter), the
          conclusions and findings of such firm with respect to the financial
          information and other matters covered by the initial letter and (iii)
          confirming in all material respects the conclusions and findings set
          forth in the initial letter.

               (m)  The Company shall have furnished to the Representatives a
          certificate, dated such Delivery Date, of its Chief Executive Officer
          or President and its Chief Financial Officer stating that:

                    (i)  The representations, warranties and agreements of the
               Company in Section 1 are true and correct as of such Delivery
               Date; the Company has complied with all its agreements contained
               herein; none of the events described in clause (i) or (ii) of
               Section 14(q) have occurred or identifying all such events as
               have occurred; and the conditions set forth in Sections 14(a) and
               14(t) have been fulfilled; and

                    (ii) They have carefully examined the Registration Statement
               and the Prospectus and, in their opinion (A) as of the Effective
               Date, the Registration Statement and Prospectus did not include
               any untrue 

                                       33

 
               statement of a material fact and did not omit to state a material
               fact required to be stated therein or necessary to make the
               statements therein not misleading, and (B) since the Effective
               Date no event has occurred which should have been set forth in a
               supplement or amendment to the Registration Statement or the
               Prospectus.

               (n) Each of the Crown Selling Stockholders (or the Custodian or
          one or more attorneys-in-fact on behalf of each of the Crown Selling
          Stockholders) shall have furnished to the Representatives on the First
          Delivery Date a certificate, dated the First Delivery Date, signed by,
          or on behalf of, each of the Crown Selling Stockholders (or the
          Custodian or one or more attorneys-in-fact) stating that the
          representations, warranties and agreements of each of the Crown
          Selling Stockholders contained herein are true and correct as of the
          First Delivery Date and that each of the Crown Selling Stockholders
          has complied with all agreements contained herein to be performed by
          each of the Crown Selling Stockholders at or prior to the First
          Delivery Date.

               (o) Each Option Selling Stockholder (or one or more attorneys-in-
          fact on behalf of such Selling Stockholder), shall have furnished to
          the Representatives on the Second Delivery Date a certificate, dated
          the Second Delivery Date, signed by, or on behalf of, such Selling
          Stockholder (or the Custodian or one or more attorneys-in-fact)
          stating that the representations, warranties and agreements of such
          Selling Stockholder contained herein are true and correct as of the
          Second Delivery Date and that such Selling Stockholder has complied
          with all agreements contained herein to be performed by such Selling
          Stockholder at or prior to the Second Delivery Date.

               (p) The Company shall have furnished to the Representatives a
          certificate, substantially in the Form of Exhibit C hereto, dated the
          First Delivery Date, of its Chief Financial Officer with respect to
          certain data of the Company set forth in the Prospectus.

               (q) (i)  Neither the Company nor any of its subsidiaries shall
          have sustained since the date of the latest audited financial
          statements included in the Prospectus any loss or interference with
          its business from fire, explosion, flood or other calamity, whether or
          not covered by insurance, or from any labor dispute or court or
          governmental action, order or decree, otherwise than as set forth or
          contemplated in the Prospectus or (ii) since such date there shall not
          have been any change in the capital stock or long-term debt of the
          Company or any of its subsidiaries or any change, or any development
          involving a prospective change, in or affecting the general affairs,
          management, financial position, stockholders' equity or results of
          operations, business or prospects of the Company and its subsidiaries,
          otherwise than as set forth or contemplated in the Prospectus, the
          effect of which, in any such case described in clause (i) or (ii), is,
          in the judgment

                                       34

 
          of the Representatives, so material and adverse as to make it
          impracticable or inadvisable to proceed with the public offering or
          the delivery of the Stock being delivered on such Delivery Date on the
          terms and in the manner contemplated in the Prospectus.

               (r) Subsequent to the execution and delivery of this Agreement
          (i) no downgrading shall have occurred in the rating accorded any of
          the Company's securities by any "nationally recognized statistical
          rating organization", as that term is defined by the Commission for
          purposes of Rule 436(g)(2) of the Rules and Regulations and (ii) no
          such organization shall have publicly announced that it has under
          surveillance or review, with possible negative implications, its
          rating of any of the Company's securities.

               (s) Subsequent to the execution and delivery of this Agreement
          there shall not have occurred any of the following: (i) trading in
          securities generally on the New York Stock Exchange or the American
          Stock Exchange or in the over-the-counter market, or trading in any
          securities of the Company on any exchange or in the over-the-counter
          market, shall have been suspended or minimum prices shall have been
          established on any such exchange or such market by the Commission, by
          such exchange or by any other regulatory body or governmental
          authority having jurisdiction, (ii) a banking moratorium shall have
          been declared by Federal or state authorities, (iii) the United States
          shall have become engaged in hostilities, there shall have been an
          escalation in hostilities involving the United States or there shall
          have been a declaration of a national emergency or war by the United
          States or (iv) there shall have occurred such a material adverse
          change in general economic, political or financial conditions (or the
          effect of international conditions on the financial markets in the
          United States shall be such) as to make it, in the judgment of a
          majority in interest of the several U.S. Underwriters, impracticable
          or inadvisable to proceed with the public offering or delivery of the
          Stock being delivered on such Delivery Date on the terms and in the
          manner contemplated in the Prospectus.

               (t) The NASDAQ National Market System shall have approved the
          Stock for inclusion, subject only to official notice of issuance and
          evidence of satisfactory distribution.

               (u) CTI and CTSH shall have received from Credit Suisse First
          Boston, as arranger and agent, and J.P. Morgan Securities Ltd., as co-
          arranger, and from each lender under the Loan Amendment Agreement
          dated May 21, 1997, an irrevocable consent and waiver to certain
          changes of control provisions of such agreement as applicable to the
          Roll-Up, and the Company shall provide a copy of such consent and
          waiver to the Representatives.

                                       35

 
               (v)  The Company shall have concluded the Stock Split and the
          Conversions and shall have reclassified all shares of Class B Common
          Stock as Common Stock (each as defined in the Prospectus).

               (w)  The Company shall have delivered to the Representatives
          copies of the Governance Agreement, the Stockholders Agreement, the
          CTSH Shareholders' Agreement and the CTI Services Agreement (each as
          defined in the Prospectus) executed and delivered by all parties
          thereto.

               (x)  The Company shall have delivered to the Representatives
          copies of written documentation evidencing (i) the ruling of the FCC
          under Section 310(b)(4) of the Communications Act of 1934, as amended,
          permitting up to 49.9% foreign ownership of the Company, at least 25%
          of which will be from World Trade Organization member nations.

               (y)  The Representatives shall have received from each
          stockholder of the Company an executed letter in the form of Exhibit A
          pursuant to Section 8(i) hereto.

               (z)  The Representatives shall have received a copy of the
          executed Custody Agreement and Power of Attorney from each Selling
          Stockholder.

               (aa) The closing under the International Underwriting Agreement
          shall have occurred concurrently with the closing hereunder on the
          First Delivery Date.

          All opinions, letters, evidence and certificates mentioned above or
elsewhere in this Agreement shall be deemed to be in compliance with the
provisions hereof only if they are in form and substance  reasonably
satisfactory to counsel for the U.S. Underwriters.

          15.  Indemnification and Contribution.

               (a)  The Company, the Crown Selling Stockholders and the
          Executive Selling Stockholders, jointly and severally, shall indemnify
          and hold harmless each U.S. Underwriter, its officers and employees
          and each person, if any, who controls any U.S. Underwriter within the
          meaning of the Securities Act, from and against any loss, claim,
          damage or liability, joint or several, or any action in respect
          thereof (including, but not limited to, any loss, claim, damage,
          liability or action relating to purchases and sales of Stock), to
          which that U.S. Underwriter, officer, employee or controlling person
          may become subject, under the Securities Act or otherwise, insofar as
          such loss, claim, damage, liability or action arises out of, or is
          based upon, (i) any breach of the representations and warranties of
          such Crown Selling Stockholder or Executive Selling Stockholder, as
          the case may be, contained herein, (ii) any untrue statement or
          alleged untrue statement of a material fact contained in any
          Preliminary Prospectus, the Registration Statement or the Prospectus
          or in any amendment or supplement thereto, (iii) the omission or

                                       36

 
          alleged omission to state in any Preliminary Prospectus, the
          Registration Statement or the Prospectus, or in any amendment or
          supplement thereto, any material fact required to be stated therein or
          necessary to make the statements therein not misleading or (iv) any
          act or failure to act or any alleged act or failure to act by any U.S.
          Underwriter in connection with, or relating in any manner to, the
          Stock or the offering contemplated hereby, and which is included as
          part of or referred to in any loss, claim, damage, liability or action
          arising out of or based upon matters covered by clause (ii) or (iii)
          above (provided that the Company, the Crown Selling Stockholders and
          the Executive Selling Stockholders shall not be liable under this
          clause (iv) to the extent that it is determined in a final judgment by
          a court of competent jurisdiction that such loss, claim, damage,
          liability or action resulted directly from any such acts or failures
          to act undertaken or omitted to be taken by such U.S. Underwriter
          through its gross negligence or willful misconduct), and shall
          reimburse each U.S. Underwriter and each such officer, employee or
          controlling person promptly upon demand for any legal or other
          expenses reasonably incurred by that U.S. Underwriter, officer,
          employee or controlling person in connection with investigating or
          defending or preparing to defend against any such loss, claim, damage,
          liability or action as such expenses are incurred; provided, however,
          that the Company, the Crown Selling Stockholders and the Executive
          Selling Stockholders shall not be liable in any such case to the
          extent that any such loss, claim, damage, liability or action arises
          out of, or is based upon, any untrue statement or alleged untrue
          statement or omission or alleged omission made in any Preliminary
          Prospectus, the Registration Statement or the Prospectus, or in any
          such amendment or supplement, in reliance upon and in conformity with
          written information concerning such U.S. Underwriter furnished to the
          Company through the Representatives by or on behalf of any U.S.
          Underwriter specifically for inclusion therein; provided further that
          neither the Company nor any Crown Selling Stockholder or Executive
          Selling Stockholder shall be liable to any U.S. Underwriter under the
          indemnity agreement in this paragraph 15(a) with respect to any
          Preliminary Prospectus to the extent that any such loss, claim, damage
          or liability of such U.S. Underwriters results from the fact that such
          U.S. Underwriter sold shares of Common Stock to a person as to whom
          there was not sent or given, at or prior to written confirmation of
          such sale, a copy of the Prospectus as then amended or supplemented if
          the Company had previously furnished copies thereof in the quantity
          requested and in a timely manner in accordance with Section 8(c)
          hereof to such U.S. Underwriter and the loss, claim, damage or
          liability of such U.S. Underwriter results from an untrue statement or
          omission of a material fact contained in the Preliminary Prospectus
          and corrected in the Prospectus as amended or supplemented.
          Notwithstanding the foregoing provisions, the indemnity and
          contribution obligations of the Crown Selling Stockholders and the
          Executive Selling Stockholders shall be subject to the following
          additional limitations: (i) the U.S. Underwriters shall pursue and
          satisfy any and all claims arising under this Agreement or otherwise
          (collectively,

                                       37

 
          "Claims") by seeking recovery from the Company prior to pursuing any
          Claim against the Crown Selling Stockholders or the Executive Selling
          Stockholders, and the U.S. Underwriters shall thereafter be entitled
          to pursue any remaining unsatisfied Claims by seeking recovery from
          the Crown Selling Stockholders and the Executive Selling Stockholders
          only following the Company's failure to satisfy in full the Claims as
          a result of the Company's insolvency, bankruptcy or liquidation; (ii)
          the aggregate amount of any Selling Stockholder's indemnity and
          contribution obligations under this paragraph 15(a) shall not exceed
          the net cash proceeds received by such Selling Stockholder from its
          sale of Stock in the offering after reduction for (A) taxes, (B)
          underwriting commissions and discounts, (C) other fees and expenses
          incurred by such Selling Stockholder relating to the offering,
          including legal and financial advisory fees, and (D) the aggregate
          amount of any and all direct and indirect costs or expenses incurred
          by such Selling Stockholder in defense or settlement of any other
          claim against it relating or attributable to the offering or the sale
          of shares of Stock by such Selling Stockholder thereunder, including
          without limitation claims under the Act; and (iii) the Crown Selling
          Stockholders and the Executive Selling Stockholders shall be liable
          under this paragraph 15(a) solely with respect to any untrue statement
          of material fact contained in the Registration Statement and the
          Prospectus which was actually known by such Selling Stockholder as of
          the date of the Registration Statement or Prospectus (or such
          amendment or supplement thereto) to be untrue, or any omission to
          state a material fact which was actually known by such Selling
          Stockholder as of the date of the Registration Statement or Prospectus
          (or such amendment or supplement thereto) to be necessary to make the
          statements contained in the Registration Statement or Prospectus (or
          such amendment or supplement thereto) in the light of the
          circumstances under which they were made, not misleading as of the
          date of the Registration Statement or Prospectus (or such amendment or
          supplement thereto). The provisions of this Section 15 shall
          constitute the sole and exclusive remedy available to the U.S.
          Underwriters with respect to any claims against the Crown Selling
          Stockholders and the Executive Selling Stockholders relating to the
          offering or sale of shares by such Selling Stockholders hereunder.

               (b) Each Employee Selling Stockholder and each Sponsor Selling
          Stockholder, severally and not jointly, shall indemnify and hold
          harmless each U.S. Underwriter, its officers and employees, and each
          person, if any, who controls any U.S. Underwriter within the meaning
          of the Securities Act, from and against any loss, claim, damage or
          liability, or any action in respect thereof (including, but not
          limited to, any loss, claim, damage, liability or action relating to
          purchases and sales of Stock), to which that U.S. Underwriter,
          officer, employee or controlling person may become subject, under the
          Securities Act or otherwise, insofar as such loss, claim, damage,
          liability or action arises out of, or is based upon, (i) any
          breach of the representations and warranties of such Employee Selling
          Stockholder or Sponsor Selling Stockholder, as the case may 

                                       38

 
          be, contained herein, (ii) any untrue statement or alleged untrue
          statement of a material fact contained in any Preliminary Prospectus,
          the Registration Statement or the Prospectus or in any amendment or
          supplement thereto or (iii) the omission or alleged omission to state
          in any Preliminary Prospectus, Registration Statement or the
          Prospectus, or in any amendment or supplement thereto, any material
          fact required to be stated therein or necessary to make the statements
          therein not misleading, in each case to the extent, but only to the
          extent, that such untrue statement or alleged untrue statement or
          omission or alleged omission relates to information provided to the
          Company or the Representatives in writing by such Selling Stockholder
          specifically for use in the Registration Statement, the Preliminary
          Prospectus or the Prospectus or to any breach of the representations
          and warranties made by such Employee Selling Stockholder or such
          Sponsor Selling Stockholder in Section 4 of this Agreement; and shall
          reimburse each U.S. Underwriter, its officers and employees and each
          such controlling person for any legal or other expenses reasonably
          incurred by that U.S. Underwriter, its officers and employees or
          controlling person in connection with investigating or defending or
          preparing to defend against any such loss, claim, damage, liability or
          action as such expenses are incurred; provided, however, that such
          Employee Selling Stockholder or such Sponsor Selling Stockholder shall
          not be liable in any such case to the extent that any such loss,
          claim, damage, liability or action arises out of, or is based upon,
          any untrue statement or alleged untrue statement or omission or
          alleged omission made in any Preliminary Prospectus, the Registration
          Statement or the Prospectus or in any such amendment or supplement in
          reliance upon and in conformity with written information concerning
          such U.S. Underwriter furnished to the Company through the
          Representatives by or on behalf of any U.S. Underwriter specifically
          for inclusion therein.; provided further that no Employee Selling
          Stockholder or Sponsor Selling Stockholder shall be liable to any U.S.
          Underwriter under the indemnity agreement in this paragraph 15(a) with
          respect to any Preliminary Prospectus to the extent that any such
          loss, claim, damage or liability of such U.S. Underwriters results
          from the fact that such U.S. Underwriter sold shares of Common Stock
          to a person as to whom there was not sent or given, at or prior to
          written confirmation of such sale, a copy of the Prospectus as then
          amended or supplemented if the Company had previously furnished copies
          thereof in the quantity requested and in a timely manner in accordance
          with Section 8(c) hereof to such U.S. Underwriter and the loss, claim,
          damage or liability of such U.S. Underwriter results from an untrue
          statement or omission of a material fact contained in the Preliminary
          Prospectus and corrected in the Prospectus as amended or supplemented.
          The foregoing indemnity agreement constitutes the sole and exclusive
          remedy available to the U.S. Underwriters with respect to any claims
          against the Employee Selling Stockholders and the Sponsor Selling
          Stockholders relating to the offering or sale of Shares by such
          Selling Stockholders hereunder.

                                       39

 
               (c)  Each U.S. Underwriter, severally and not jointly, shall
          indemnify and hold harmless the Company, its officers who sign the
          Registration Statement, each of its directors (including any person
          who, with his or her consent, is named in the Registration Statement
          as about to become a director of the Company), and each person, if
          any, who controls the Company within the meaning of the Securities
          Act, from and against any loss, claim, damage or liability, joint or
          several, or any action in respect thereof, to which the Company or any
          such director, officer or controlling person may become subject, under
          the Securities Act or otherwise, insofar as such loss, claim, damage,
          liability or action arises out of, or is based upon, (i) any untrue
          statement or alleged untrue statement of a material fact contained in
          any Preliminary Prospectus, the Registration Statement or the
          Prospectus or in any amendment or supplement thereto or (ii) the
          omission or alleged omission to state in any Preliminary Prospectus,
          the Registration Statement or the Prospectus, or in any amendment or
          supplement thereto, any material fact required to be stated therein or
          necessary to make the statements therein not misleading, but in each
          case only to the extent that the untrue statement or alleged untrue
          statement or omission or alleged omission was made in reliance upon
          and in conformity with written information concerning such U.S.
          Underwriter furnished to the Company through the Representatives by or
          on behalf of that U.S. Underwriter specifically for inclusion therein,
          and shall reimburse the Company and any such director, officer or
          controlling person for any legal or other expenses reasonably incurred
          by the Company or any such director, officer or controlling person in
          connection with investigating or defending or preparing to defend
          against any such loss, claim, damage, liability or action as such
          expenses are incurred.  The foregoing indemnity agreement is in
          addition to any liability which any U.S. Underwriter may otherwise
          have to the Company or any such director, officer, employee or
          controlling person.

               (d)  Promptly after receipt by an indemnified party under this
          Section 15 of notice of any claim or the commencement of any action,
          the indemnified party shall, if a claim in respect thereof is to be
          made against the indemnifying party under this Section 15, notify the
          indemnifying party in writing of the claim or the commencement of that
          action; provided, however, that the failure to notify the indemnifying
          party shall not relieve it from any liability which it may have under
          this Section 15 except to the extent it has been materially prejudiced
          by such failure and, provided further, that the failure to notify the
          indemnifying party shall not relieve it from any liability which it
          may have to an indemnified party otherwise than under this Section 15.
          If any such claim or action shall be brought against an indemnified
          party, and it shall notify the indemnifying party thereof, the
          indemnifying party shall be entitled to participate therein and, to
          the extent that it wishes, jointly with any other similarly notified
          indemnifying party, to assume the defense thereof with counsel
          reasonably satisfactory to the indemnified party.  After notice from
          the indemnifying party to the indemnified party of its election to
          assume the defense of such claim or action, the 

                                       40

 
          indemnifying party shall not be liable to the indemnified party under
          this Section 15 for any legal or other expenses subsequently incurred
          by the indemnified party in connection with the defense thereof;
          provided, however, that if the defendants in any such action include
          both the indemnified party and the indemnifying party and the
          indemnified party shall have in good faith reasonably concluded that
          there may be defenses available to it which are different from or
          additional to those available to the indemnifying party or if the
          interests of the indemnified party may be deemed to conflict with the
          interests of the indemnifying party, the indemnified party shall have
          the right to select a separate counsel in the defense of such action,
          with the expenses and fees of such separate counsel and other expenses
          related to such participation to be reimbursed by the indemnifying
          party as incurred, provided further that in no event shall the
          foregoing proviso require the indemnifying party to bear the fees and
          expenses of more than one separate counsel to represent jointly each
          of (i) the Representatives and those other U.S. Underwriters and their
          respective officers, employees and controlling persons who may be
          subject to liability arising out of any claim in respect of which
          indemnity may be sought under this Section 15, (ii) the Company and
          its Subsidiaries, (iii) the Crown Selling Stockholders, (iv) the
          Executive Selling Stockholders, (v) the Employee Selling Stockholders
          and (vi) the Sponsor Selling Stockholders. No indemnifying party shall
          (i) without the prior written consent of the indemnified parties
          (which consent shall not be unreasonably withheld), settle or
          compromise or consent to the entry of any judgment with respect to any
          pending or threatened claim, action, suit or proceeding in respect of
          which indemnification or contribution may be sought hereunder (whether
          or not the indemnified parties are actual or potential parties to such
          claim or action) unless such settlement, compromise or consent
          includes an unconditional release of each indemnified party from all
          liability arising out of such claim, action, suit or proceeding, or
          (ii) be liable for any settlement of any such action effected without
          its written consent (which consent shall not be unreasonably
          withheld), but if settled with the consent of the indemnifying party
          or if there be a final judgment of the plaintiff in any such action,
          the indemnifying party agrees to indemnify and hold harmless any
          indemnified party from and against any loss or liability by reason of
          such settlement or judgment to the extent provided in this Section 15.

               (e)  If the indemnification provided for in this Section 15 shall
          for any reason be unavailable to or insufficient (other than by reason
          of the exceptions provided therein) to hold harmless an indemnified
          party under Section 15(a), 15(b) or 15(c) in respect of any loss,
          claim, damage or liability, or any action in respect thereof, referred
          to therein, then each indemnifying party shall, in lieu of
          indemnifying such indemnified party, contribute to the amount paid or
          payable by such indemnified party as a result of such loss, claim,
          damage or liability, or action in respect thereof, (i) in such
          proportion as shall be appropriate to reflect the relative benefits
          received by the Company, the Crown Selling Stockholders, the Executive
          Selling Stockholders, the Employee Selling Stockholders and the

                                       41

 
          Sponsor Selling Stockholders on the one hand and the U.S. Underwriters
          on the other from the offering of the Stock or (ii) if the allocation
          provided by clause (i) above is not permitted by applicable law, in
          such proportion as is appropriate to reflect not only the relative
          benefits referred to in clause (i) above but also the relative fault
          of the Company, the Crown Selling Stockholders, the Executive Selling
          Stockholders, the Employee Selling Stockholders and the Sponsor
          Selling Stockholders on the one hand and the U.S. Underwriters on the
          other with respect to the statements or omissions which resulted in
          such loss, claim, damage or liability, or action in respect thereof,
          as well as any other relevant equitable considerations. The relative
          benefits received by the Company, the Crown Selling Stockholders, the
          Executive Selling Stockholders, the Employee Selling Stockholders or
          the Sponsor Selling Stockholders, on the one hand and the U.S.
          Underwriters on the other with respect to such offering shall be
          deemed to be in the same proportion as the total net proceeds from the
          offering of the Stock purchased under this Agreement (before deducting
          expenses) received by the Company, the Crown Selling Stockholders, the
          Executive Selling Stockholders, the Employee Selling Stockholders or
          the Sponsor Selling Stockholders, on the one hand, and the total
          underwriting discounts and commissions received by the U.S.
          Underwriters with respect to the shares of the Stock purchased under
          this Agreement, on the other hand, bear to the total gross proceeds
          from the offering of the shares of the Stock under this Agreement, in
          each case as set forth in the table on the cover page of the
          Prospectus. The relative fault shall be determined by reference to
          whether the untrue or alleged untrue statement of a material fact or
          omission or alleged omission to state a material fact relates to
          information supplied by the Company, the Crown Selling Stockholders,
          the Executive Selling Stockholders, the Employee Selling Stockholders,
          the Sponsor Selling Stockholders or the U.S. Underwriters, the intent
          of the parties and their relative knowledge, access to information and
          opportunity to correct or prevent such statement or omission. The
          Company, the Crown Selling Stockholders, the Executive Selling
          Stockholders, the Employee Selling Stockholders, the Sponsor Selling
          Stockholders and the U.S. Underwriters agree that it would not be just
          and equitable if contributions pursuant to this Section 15 were to be
          determined by pro rata allocation (even if the U.S. Underwriters were
          treated as one entity for such purpose) or by any other method of
          allocation which does not take into account the equitable
          considerations referred to herein. The amount paid or payable by an
          indemnified party as a result of the loss, claim, damage or liability,
          or action in respect thereof, referred to above in this Section 15
          shall be deemed to include, for purposes of this Section 15(e), any
          legal or other expenses reasonably incurred by such indemnified party
          in connection with investigating or defending any such action or
          claim. Notwithstanding the provisions of this Section 15(e), no U.S.
          Underwriter shall be required to contribute any amount in excess of
          the amount by which the total price at which the Stock underwritten by
          it and distributed to the public was offered to the public exceeds the
          amount of any damages which such U.S. Underwriter has otherwise paid
          or become liable to pay by reason of any 

                                       42

 
          untrue or alleged untrue statement or omission or alleged omission. No
          Selling Stockholder will be required to contribute any amount in
          excess of the proceeds received by such person in respect of all
          shares of Stock offered and sold by it pursuant to the Registration
          Statement and no person guilty of fraudulent misrepresentation (within
          the meaning of Section 11(f) of the Securities Act) shall be entitled
          to contribution from any person who was not guilty of such fraudulent
          misrepresentation. The U.S. Underwriters' obligations to contribute as
          provided in this Section 15(e) are several in proportion to their
          respective underwriting obligations and not joint.

               (f)  The U.S. Underwriters severally confirm and the Company
          acknowledges that (i) the last paragraph on the cover page of the
          Prospectus, (ii) the stabilization legend at the top of page i of the
          Prospectus and (iii) the fourth, ninth, tenth, eleventh, and twenty-
          second paragraphs and the first sentence of the thirteenth paragraph
          under the caption "Underwriting" in the Prospectus constitute the only
          information concerning such U.S. Underwriters furnished in writing to
          the Company by or on behalf of the U.S. Underwriters specifically for
          inclusion in the Registration Statement and the Prospectus.

               (g)  As used herein, the phrase "actual knowledge" means, with
          respect to any natural person, the knowledge of such person and, with
          respect to any other person, the knowledge of any natural person
          exercising control (whether by ownership or management) over such
          person, and shall not imply any duty to investigate or be deemed to
          include any knowledge that might have become actually known following
          investigation. The phrase "actually known" shall have a correlative
          meaning.

          16.  Defaulting U.S. Underwriters.

          If, on either Delivery Date, any U.S. Underwriter defaults in the
performance of its obligations under this Agreement, the remaining non-
defaulting U.S. Underwriters shall be obligated to purchase the Firm Stock which
the defaulting U.S. Underwriter agreed but failed to purchase on such Delivery
Date in the respective proportions which the number of shares of the Firm Stock
set opposite the name of each remaining non-defaulting U.S. Underwriter in
Schedules 1 and 2 hereto bears to the total number of shares of the Firm Stock
set opposite the names of all the remaining non-defaulting U.S. Underwriters in
Schedules 1 and 2 hereto; provided, however, that the remaining non-defaulting
U.S. Underwriters shall not be obligated to purchase any of the Stock on such
Delivery Date if the total number of shares of the Stock which the defaulting
U.S. Underwriter or U.S. Underwriters agreed but failed to purchase on such date
exceeds 9.9% of the total number of shares of the Stock to be purchased on such
Delivery Date, and any remaining non-defaulting U.S. Underwriter shall not be
obligated to purchase more than 110% of the number of shares of the Stock which
it agreed to purchase on such Delivery Date pursuant to the terms of Section 7.
If the foregoing maximums are exceeded, the remaining non-defaulting U.S.
Underwriters, or those other U.S. Underwriters satisfactory to the

                                       43

 
Representatives who so agree, shall have the right, but shall not be obligated,
to purchase, in such proportion as may be agreed upon among them, all the Stock
to be purchased on such Delivery Date. If the remaining U.S. Underwriters or
other underwriters satisfactory to the Representatives do not elect to purchase
the shares which the defaulting U.S. Underwriter or U.S. Underwriters agreed but
failed to purchase on such Delivery Date, this Agreement (or, with respect to
the Second Delivery Date, the obligation of the U.S. Underwriters to purchase,
and of the Executive Selling Stockholders, the Employee Selling Stockholders and
the Sponsor Selling Stockholders to sell, the Option Stock) shall terminate
without liability on the part of any non-defaulting U.S. Underwriter or the
Company or the Selling Stockholders, except that the Company will continue to be
liable for the payment of expenses to the extent set forth in Sections 13 and
18. As used in this Agreement, the term "U.S. Underwriter" includes, for all
purposes of this Agreement unless the context requires otherwise, any party not
listed in Schedules 1 and 2 hereto who, pursuant to this Section 16, purchases
Firm Stock which a defaulting U.S. Underwriter agreed but failed to purchase.

          Nothing contained herein shall relieve a defaulting U.S. Underwriter
of any liability it may have to the Company and the Selling Stockholders for
damages caused by its default.  If other U.S. Underwriters are obligated or
agree to purchase the Stock of a defaulting or withdrawing U.S. Underwriter,
either the Representatives or the Company may postpone the Delivery Date for up
to seven full business days in order to effect any changes that, in the opinion
of counsel for the Company or counsel for the U.S. Underwriters, may be
necessary in the Registration Statement, the Prospectus or in any other document
or arrangement.

          17.  Termination.  The obligations of the U.S. Underwriters hereunder
may be terminated by the Representatives by notice given to and received by the
Company and the Selling Stockholders prior to delivery of and payment for Firm
Stock if, prior to that time, any of the events described in Sections 14(q),
14(r) or 14(s) shall have occurred or if the U.S. Underwriters shall decline to
purchase the Stock for any reason permitted under this Agreement.

          18.  Reimbursement of U.S. Underwriters' Expenses.  If the Company or
any of the Selling Stockholders shall fail to tender the Stock for delivery to
the U.S. Underwriters by reason of any failure, refusal or inability on the part
of the Company or any Selling Stockholder to perform any agreement on its part
to be performed, or because any other condition of the U.S. Underwriters'
obligations hereunder required to be fulfilled by the Company or the Selling
Stockholders is not fulfilled, the Company or any such defaulting Selling
Stockholder(s), as the case may be, will severally and not jointly, in
proportion to the shares of Stock to be sold by the Company or such defaulting
Selling Stockholder(s) hereunder, reimburse the U.S. Underwriters for all
reasonable out-of-pocket expenses (including fees and disbursements of counsel)
incurred by the U.S. Underwriters in connection with this Agreement and the
proposed purchase of the Stock, and upon demand the Company or such defaulting
Selling Stockholder(s), as the case may be,  shall pay the full amount thereof
to the Representatives.  Neither the Company nor any Selling Stockholder shall
have the liability to any of the U.S. Underwriters for damages on account of
loss of anticipated profits from the proposed sale by them of the Stock.

                                       44

 
          19.  Notices, etc.  All statements, requests, notices and agreements
hereunder shall be in writing, and:

               (a)  if to the U.S. Underwriters, shall be delivered or sent by
          mail, telex or facsimile transmission to Lehman Brothers Inc., Three
          World Financial Center, New York, New York 10285, Attention: Syndicate
          Department (Fax: 212-526-6588), with a copy, in the case of any notice
          pursuant to Section 15(d), to the Director of Litigation, Office of
          the General Counsel, Lehman Brothers Inc., Three World Financial
          Center, 10th Floor, New York, NY 10285;

               (b)  if to the Company, shall be delivered or sent by mail, telex
          or facsimile transmission to the address of the Company set forth in
          the Registration Statement, Attention: Charles C. Green, III, (Fax:
          (713) 570-3150), with a copy to Cravath, Swaine & Moore, Worldwide
          Plaza, 825 Eighth Avenue, New York, New York 10019, Attention: Stephen
          L. Burns (Fax: (212) 474-3700);

               (c)  if to any Selling Stockholder, shall be delivered or sent by
          mail, telex or facsimile transmission to such Selling Stockholder at
          the address set forth in the Custody Agreement executed by such
          Selling Shareholder, with a copy (a) in the case of any Crown Selling
          Stockholder, to Kirkpatrick & Lockhart, 1500 Oliver Building,
          Pittsburgh, Pennsylvania 15222, Attention: Jerry Owens (Fax: (412)
          355-6501), (b) in the case of any Executive Selling Stockholder or
          Employee Selling Stockholder, to Brown, Parker & Leahy, L.L.P., 3600
          Two Allen Center, 1200 Smith Street, Houston, Texas 77002, Attention:
          E. Blake Hawk (Fax: (713) 654-1871) or (c) in the case of any Sponsor
          Selling Stockholder, to Hutchins, Wheeler & Dittmar, 101 Federal
          Street, Boston, Massachusetts 02110, Attention: Harry A. Hanson, III
          (Fax: (617) 951-1295);

provided, however, that any notice to an U.S. Underwriter pursuant to Section
15(d) shall be delivered or sent by mail, telex or facsimile transmission to
such U.S. Underwriter at its address set forth in its acceptance telex to the
Representatives, which address will be supplied to any other party hereto by the
Representatives upon request. Any such statements, requests, notices or
agreements shall take effect at the time of receipt thereof. The Company and the
Selling Stockholders shall be entitled to act and rely upon any request,
consent, notice or agreement given or made on behalf of the U.S. Underwriters by
Lehman Brothers Inc., Credit Suisse First Boston Corporation, Goldman, Sachs &
Co., and Smith Barney Inc. and the Company and the U.S. Underwriters shall be
entitled to act and rely upon any request, consent, notice or agreement given or
made on behalf of the Selling Stockholders by their respective Custodians.

          20.  Persons Entitled to Benefit of Agreement.  This Agreement shall
inure to the benefit of and be binding upon the U.S. Underwriters, the Company
and the Selling Stockholders and their respective personal representatives and
successors. This Agreement and the terms and provisions hereof are for the sole
benefit of only those persons, except that (A) the representations, warranties,
indemnities and agreements of the Company and the Selling Stockholders contained
in this Agreement shall also be deemed to be for the benefit of the person 

                                       45

 
or persons, if any, who control any U.S. Underwriter within the meaning of
Section 17 of the Securities Act and for the benefit of each International
Manager (and controlling persons thereof) who offers or sells any shares of
Common Stock in accordance with the terms of the Agreement Between U.S.
Underwriters and International Managers and (B) the indemnity agreement of the
U.S. Underwriters contained in Section 15(c) of this Agreement shall be deemed
to be for the benefit of directors of the Company, officers of the Company who
have signed the Registration Statement and any person controlling the Company
within the meaning of Section 17 of the Securities Act. Nothing in this
Agreement is intended or shall be construed to give any person, other than the
persons referred to in this Section 20, any legal or equitable right, remedy or
claim under or in respect of this Agreement or any provision contained herein.

          21.  Survival.  The respective indemnities, representations,
warranties and agreements of the Company, the Selling Stockholders and the U.S.
Underwriters contained in this Agreement or made by or on behalf on them,
respectively, pursuant to this Agreement, shall survive the delivery of and
payment for the Stock and shall remain in full force and effect, regardless of
any investigation made by or on behalf of any of them or any person controlling
any of them.

          22.  Definition of the Terms "Business Day" and "Subsidiary".  For
purposes of this Agreement, (a) "business day" means any day on which the New
York Stock Exchange, Inc. is open for trading and (b) "subsidiary" has the
meaning set forth in Rule 405 of the Rules and Regulations.

          23.  Governing Law.  THIS AGREEMENT SHALL BE GOVERNED BY AND CONSTRUED
IN ACCORDANCE WITH THE LAWS OF NEW YORK WITHOUT GIVING EFFECT TO ANY PROVISIONS
RELATING TO CONFLICTS OF LAW.

          24.  Counterparts.  This Agreement may be executed in one or more
counterparts and, if executed in more than one counterpart, the executed
counterparts shall each be deemed to be an original but all such counterparts
shall together constitute one and the same instrument.

          25.  Headings.  The headings herein are inserted for convenience of
reference only and are not intended to be part of, or to affect the meaning or
interpretation of, this Agreement.

                                       46

 
          If the foregoing correctly sets forth the agreement among the Company,
the Crown Selling Stockholders, the Executive Selling Stockholders, the Employee
Selling Stockholders, the Sponsor Selling Stockholders and the U.S.
Underwriters, please indicate your acceptance in the space provided for that
purpose below.


                              Very truly yours,

                              Crown Castle International Corp.

                              By:_________________________________
                                 Name:____________________________
                                 Title:

                              Robert A. Crown

                              By:_________________________________
                                 Name: ___________________________
                                 Attorney-In-Fact

                              Barbara A. Crown

                              By:_________________________________
                                 Name: ___________________________
                                 Attorney-In-Fact

                              Robert A. Crown and PNC Bank, Delaware, as
                              trustees for the Robert A. Crown Grantor Retained
                              Annuity Trust

                              By:_________________________________
                                 Name: ___________________________
                                 Attorney-In-Fact

                              By:_________________________________
                                 Name: ___________________________
                                 Attorney-In-Fact

                                       47

 
                              Barbara A. Crown and PNC Bank, Delaware, as
                              trustees for the Barbara A. Crown Grantor Retained
                              Annuity Trust

                              By:_________________________________
                                 Name: ___________________________
                                 Attorney-In-Fact


                              By:_________________________________
                                 Name: ___________________________
                                 Attorney-In-Fact


                              Ted B. Miller, Jr.

                              By:_________________________________
                                 Name: ___________________________
                                 Attorney-In-Fact


                              David L. Ivy

                              By:_________________________________
                                 Name: ___________________________
                                 Attorney-In-Fact

                              
                              Charles C. Green, III

                              By:_________________________________
                                 Name: ___________________________
                                 Attorney-In-Fact


                              John L. Gwyn

                              By:_________________________________
                                 Name: ___________________________
                                 Attorney-In-Fact


                              Edward C. Hutcheson, Jr.

                              By:_________________________________
                                 Name: ___________________________
                                 Attorney-In-Fact

                                       48

 
                              J. Landis Martin

                              By:_________________________________
                                 Name: ___________________________
                                 Attorney-In-Fact


                              Robert F. McKenzie

                              By:_________________________________
                                 Name: ___________________________
                                 Attorney-In-Fact


                              Tod Bettenhausen

                              By:_________________________________
                                 Name: ___________________________
                                 Attorney-In-Fact


                              Kathy Broussard

                              By:_________________________________
                                 Name: ___________________________
                                 Attorney-In-Fact


                              Bill Cordell

                              By:_________________________________
                                 Name: ___________________________
                                 Attorney-In-Fact


                              Wesley D. Cunningham

                              By:_________________________________
                                 Name: ___________________________
                                 Attorney-In-Fact


                              Angela Dennehy

                              By:_________________________________
                                 Name: ___________________________
                                 Attorney-In-Fact

                                       49

 
                              Allyn Easter

                              By:_________________________________
                                 Name: ___________________________
                                 Attorney-In-Fact


                              Martin Ellen

                              By:_________________________________
                                 Name: ___________________________
                                 Attorney-In-Fact


                              Alan Rees

                              By:_________________________________
                                 Name: ___________________________
                                 Attorney-In-Fact


                              George Reese

                              By:_________________________________
                                 Name: ___________________________
                                 Attorney-In-Fact


                              Michael Schueppert

                              By:_________________________________
                                 Name: ___________________________
                                 Attorney-In-Fact


                              Jimmy Taylor

                              By:_________________________________
                                 Name: ___________________________
                                 Attorney-In-Fact


                              Nigel Turner

                              By:_________________________________
                                 Name: ___________________________
                                 Attorney-In-Fact

                                       50

 
                              Mark Uminski

                              By: ________________________________
                                  Name: __________________________
                                  Attorney-In-Fact


                              Ed Wallander

                              By: ________________________________
                                  Name: __________________________
                                  Attorney-In-Fact


                              John Ward

                              By: ________________________________
                                  Name: __________________________
                                  Attorney-In-Fact


                              Terry Wing

                              By: ________________________________
                                  Name: __________________________
                                  Attorney-In-Fact


                              Centennial Fund IV, L.P.

                              By: ________________________________
                                  Name: __________________________
                                  Attorney-In-Fact


                              Centennial Fund V, L.P.

                              By: ________________________________
                                  Name: __________________________
                                  Attorney-In-Fact


                              Centennial Entrepreneurs Fund V, L.P.

                              By: ________________________________
                                  Name: __________________________
                                  Attorney-In-Fact

                                       51

 
                              Nassau Capital Partners II, L.P.

                              By: ________________________________
                                  Name: __________________________
                                  Attorney-In-Fact


                              NAS Partners I, L.L.C.

                              By: ________________________________
                                  Name: __________________________
                                  Attorney-In-Fact


                              American Home Assurance Company

                              By: ________________________________
                                  Name: __________________________
                                  Attorney-In-Fact


                              Harvard Private Capital Holding Inc.

                              By: ________________________________
                                  Name: __________________________
                                  Attorney-In-Fact


                              Fay, Richwhite Communications Limited

                              By: ________________________________
                                  Name: __________________________
                                  Attorney-In-Fact


                              New York Life Insurance Company

                              By: ________________________________
                                  Name: __________________________
                                  Attorney-In-Fact

                                       52

 
                              The Northwestern Mutual Life Insurance 
                                  Company

                              By: ________________________________
                                  Name: __________________________
                                  Attorney-In-Fact


                              PNC Venture Corp.

                              By: ________________________________
                                  Name: __________________________
                                  Attorney-In-Fact


                              Prime VIII, L.P.

                              By: ________________________________
                                  Name: __________________________
                                  Attorney-In-Fact


                              Win J. Neuger

                              By: ________________________________
                                  Name: __________________________
                                  Attorney-In-Fact


                              David B. Pinkerton

                              By: ________________________________
                                  Name: __________________________
                                  Attorney-In-Fact


                              Peter F. Smith

                              By: ________________________________
                                  Name: __________________________
                                  Attorney-In-Fact

                                       53

 
Accepted:

Lehman Brothers Inc.
Credit Suisse First Boston Corporation
Goldman, Sachs & Co.
Smith Barney Inc.

For themselves and as Representatives
of the several U.S. Underwriters named
in Schedule 1 hereto

     By Lehman Brothers Inc.

     By: __________________________
         Name:
         Title:

                                       54

 
                                  SCHEDULE 1

                                                                  Number of  
U.S. Underwriters                                                   Shares   
- -----------------                                                 ---------  
                                                                             
Lehman Brothers Inc. ..........................................              
Credit Suisse First Boston Corporation.........................              
Goldman, Sachs & Co. ..........................................              
Smith Barney Inc. .............................................              
                                                                             
                                                                  __________ 
                                                                             
     Total.....................................................   25,000,000 
                                                                  ==========  

                                       55

 
                                  SCHEDULE 2

 
 
                                                                                       NUMBER OF
CROWN SELLING STOCKHOLDERS                                                               SHARES  
- --------------------------                                                             --------- 
                                                                                    
Robert A. Crown.................................................................       1,744,875
Barbara A. Crown................................................................       1,744,875
Robert A. Crown and PNC Bank, Delaware as Trustees of the Robert A. Crown
 Grantor Retained Annuity Trust.................................................         130,125
Barbara A. Crown and PNC Bank, Delaware, as Trustees of the Barbara A. Crown
 Grantor Retained Annuity Trust.................................................         130,125
                                                                                       --------- 
  Total.........................................................................       3,750,000
                                                                                       =========

EXECUTIVE SELLING STOCKHOLDERS
- ------------------------------

Ted B. Miller, Jr...............................................................         480,535
David L. Ivy....................................................................         174,600
Charles C. Green, III...........................................................         142,800
John L. Gwyn....................................................................          57,300
Edward C. Hutcheson, Jr.........................................................          78,000
J. Landis Martin................................................................         101,285
Robert F. McKenzie..............................................................          23,700
                                                                                       ---------
  Total.........................................................................       1,058,220
                                                                                       =========

EMPLOYEE SELLING STOCKHOLDERS
- -----------------------------

Tod Bettenhausen................................................................          27,000
Kathy Broussard.................................................................          16,800
Bill Cordell....................................................................          22,000
Wesley D. Cunningham............................................................          17,395
Angela Dennehy..................................................................          25,245
Allyn Easter....................................................................          21,000
Martin Ellen....................................................................          25,245
Alan Rees.......................................................................          69,215
George Reese....................................................................         110,400
Michael Schueppert..............................................................          22,730
Jimmy Taylor....................................................................          15,000
Nigel Turner....................................................................          25,245
Mark Uminski....................................................................          15,000
Ed Wallander....................................................................          18,000
John Ward.......................................................................          25,245
Terry Wing......................................................................          24,430
                                                                                         -------
  Total.........................................................................         479,950
                                                                                         =======


                                       56

 
 
Sponsor Selling Stockholders
- ----------------------------
                                                                                    
Centennial Fund IV, L.P.........................................................         476,183
Centennial Fund V, L.P..........................................................         297,849
Centennial Entrepreneurs Fund V, L.P............................................           9,213
Nassau Capital Partners II, L.P.................................................         401,985
NAS Partners I, L.L.C...........................................................           2,500
American Home Assurance Company.................................................         220,875
Harvard Private Capital Holding Inc.............................................         172,360
Fay, Richwhite Communications Limited...........................................         222,465
New York Life Insurance Company.................................................          84,415
The Northwestern Mutual Life Insurance Company..................................         132,955
PNC Venture Corp................................................................         159,465
Prime VIII, L.P.................................................................          65,590
Win J. Neuger...................................................................             670
David B. Pinkerton..............................................................             270
Peter F. Smith..................................................................             400
                                                                                       ---------
  Total.........................................................................       2,247,195
                                                                                       =========


                                       57

 
                                                                       Exhibit A
                                                                       ---------

                               Lock-up Agreement

                                August __, 1998

Crown Castle International Corp.
 510 Bering Drive
 Suite 500
 Houston, Texas 77057

Lehman Brothers Inc.
Credit Suisse First Boston Corporation
Goldman, Sachs & Co.
Smith Barney Inc.
 As Representatives of the
 several U.S. Underwriters
  c/o Lehman Brothers Inc.
  Three World Financial Center
  New York, New York 10285

Lehman Brothers International (Europe)
Credit Suisse First Boston (Europe) Limited
Goldman, Sachs International
Smith Barney Inc.
 As Representatives of the several
 International Managers
  c/o Lehman Brothers Inc.
  Three World Financial Center
  New York, New York 10285

Ladies and Gentlemen:

          The undersigned understands that Lehman Brothers Inc., Credit Suisse
First Boston Corporation, Goldman, Sachs & Co., and Smith Barney Inc., as the
U.S. representatives of the several U.S. underwriters and Lehman Brothers
International (Europe), Credit Suisse First Boston (Europe) Limited, Goldman
Sachs International and Smith Barney Inc., as the lead managers (together with
the U.S. representatives, the "Representatives") of the several International
Managers (together with the U.S. underwriters, the "Underwriters"), propose to
enter into a U.S. underwriting agreement (the "U.S. Underwriting Agreement") and
an international underwriting agreement (the "International Underwriting
Agreement"), respectively, with Crown Castle International Corp. (the "Company")
and the other Selling Stockholders named therein, providing for the public
offering by the Underwriters, including the Representatives, of Common Stock,
par value $.01 per share (the "Common Stock"), of the 

                                       1

 
Company (the "Public Offering"). Capitalized terms not defined herein shall have
the meaning given them in the U.S. Underwriting Agreement.

          In consideration of the Underwriters' agreement to purchase and
undertake the Public Offering of the Common Stock of the Company and the Crown
Selling Stockholders and for other good and valuable consideration, receipt of
which is hereby acknowledged, the undersigned agrees that, without the prior
written consent of Lehman Brothers Inc., he, she or it will not, during the
period commencing on the date hereof and ending 180 days after the date of the
Prospectus, (i) offer, pledge, sell, contract to sell, sell any option or
contract to purchase, purchase any option or contract to sell, grant any option,
right or warrant to purchase, or otherwise transfer or dispose of, directly or
indirectly, any shares of the Common Stock or any securities convertible into or
exercisable or exchangeable for Common Stock or any right to acquire Common
Stock, or (ii) enter into any swap or similar agreement that transfers, in whole
or in part, the economic risk of ownership of the Common Stock, whether any such
transaction described in clause (i) or (ii) above is to be settled by delivery
of Common Stock or such other securities, in cash or otherwise.  The foregoing
provisions shall not apply to:  (a) the exercise of options or warrants, (b) the
sale of shares of Common Stock to the Underwriters in connection with the Public
Offering pursuant to the provisions of the U.S. Underwriting Agreement and the
International Underwriting Agreement, as applicable, (c) if the undersigned is
an individual and is an employee of the Company as of the date of the Prospectus
(other than any Crown Selling Stockholder or Executive Selling Stockholder), the
sale of up to 12% of the shares of Common Stock in the aggregate beneficially
owned by the undersigned as of the date of the Prospectus in compliance with the
registration requirements of the Securities Act pursuant to a valid exemption
therefrom; provided that if the undersigned relies on the exception in clause
(b) above, then the aggregate number of shares that may be sold pursuant to this
clause (c) shall be reduced by the number of shares sold pursuant to clause (b)
above, or (d) transfers, without consideration, of the Common Stock or any
securities convertible into, or exercisable or exchangeable for, Common Stock
(1) if the undersigned is a natural person, to family members of the
undersigned, to one or more trusts established for the benefit of one or more
family members of the undersigned or to trusts established by the undersigned
for charitable purposes or (2) if the undersigned is not a natural person, to
affiliates, members, partners, shareholders or beneficiaries of the undersigned,
provided in each case that each transferee executes and delivers to Lehman
Brothers Inc. an agreement whereby such transferee agrees to be bound by all of
the foregoing terms and provisions.

          In addition, the undersigned agrees that the Company may (i) with
respect to any shares of Common Stock for which the undersigned is the record
holder, cause the transfer agent for the Company to note stop-transfer
instructions with respect to such shares of Common Stock consistent with the
foregoing paragraph on the transfer books and records of the Company and (ii)
with respect to any shares of Common Stock for which the undersigned is the
beneficial holder but not the record holder, cause the record holder of such
shares of Common Stock to cause the transfer agent for the Company to note stop-
transfer instructions with respect to such shares of Common Stock consistent
with the foregoing paragraph on the transfer books and records of the Company.

                                       2

 
          The undersigned hereby represents and warrants that the undersigned
has full power and authority to enter into this letter agreement, and that, upon
request, the undersigned will execute any additional documents necessary or
desirable in connection with the enforcement hereof. All authority herein
conferred or agreed to be conferred shall survive the death or incapacity of the
undersigned and any obligations of the undersigned shall be binding upon the
heirs, personal representatives, successors, and assigns of the undersigned.

                                    Very truly yours,

                                    __________________________

__________________________
(Name - Please Type)

__________________________
__________________________
__________________________
(Address)

__________________________
(Social Security or Taxpayer Identification No.)

                                       3

 
                                                                       Exhibit B
                                                                       ---------


                  FORM OF OPINION FOR ENGLISH COUNSEL FOR CTI

 
                                                                       Exhibit C
                                                                       ---------


                    CERTIFICATE OF CHIEF FINANCIAL OFFICER

          The undersigned, Charles C. Green, III, Chief Financial Officer of
Crown Castle International Corp., a Delaware corporation (the "Company"),
pursuant to Section 14(p) of that certain U.S. Underwriting Agreement, dated
August __, 1998 by and among the Company, the Crown Selling Stockholders named
therein, the Executive Selling Stockholders named therein, the Employee Selling
Stockholders named therein, the Sponsor Selling Stockholders named therein,
Lehman Brothers Inc., Credit Suisse First Boston Corporation, Goldman, Sachs &
Co. and Smith Barney Inc., and pursuant to Section 7(j) of that certain
International Underwriting Agreement, dated August __, 1998, by and among the
Company, Lehman Brothers International (Europe), Credit Suisse First Boston
(Europe) Limited, Goldman Sachs International and Smith Barney Inc., does hereby
certify on behalf of the Company with respect to the registration statement on
Form S-1 (File No. 333-57283) relating to the initial public offering of shares
of the Company's common stock, and the Prospectus contained therein dated as of
August __, 1998 and as filed with the U.S. Securities and Exchange Commission
pursuant to Rule 424(b) (the "Prospectus"), that:

          1.   All data for numbers of tower, rooftop and communication sites
(collectively, "Towers") owned, leased, managed, licensed, marketed, shared
pursuant to contract, or otherwise utilized by or under the management of the
Company and each of its subsidiaries (collectively, "CCIC") or Castle
Transmission Services (Holdings) Ltd and its subsidiaries (collectively, "CTSH"
and, together with CCIC, the "Businesses"), as presented in the Prospectus,
including but not limited to such data presented under the captions identified
on Schedule I hereto (such data, whether presented in tabular or text format,
the "Tower Data"), have been prepared by officers of the Businesses, including
the Chief Financial Officer of the Company (such officers, the "Responsible
Officers").

          2.   All data for numbers of transmitters owned, leased, managed,
licensed, marketed, shared pursuant to contract, or otherwise utilized by or
under the management of the Businesses, as presented in the Prospectus,
including but not limited to such data presented under the captions identified
on Schedule I hereto (such statements, the "Transmitter Data"), have been
prepared by the Responsible Officers.

          3.   All financial data for the revenue derived from or related to
Tower Data and Transmitter Data, as presented in the Prospectus, including but
not limited to such data presented under the captions identified on Schedule I
hereto (such statements, the "Tower Revenue Statements") have been prepared by
the Responsible Officers.

          4.   The statements regarding percentage of population coverage of
analog television transmitters owned and managed by the Company, as presented in
the Prospectus under the captions identified on Schedule I hereto (such
statements, the "Population Coverage Statements") have been prepared by the
Responsible Officers.

          5.   In collecting and preparing the Tower Data and the Transmitter
Data, the undersigned (i) participated in meetings and conversations with the
Responsible Officers and 

                                       1

 
such officers of subsidiaries of the Company and CTSH responsible for the
management and evaluation of the areas of the Company's operations described in
the Prospectus (the "Subsidiary Officers") and (ii) examined the books and
records of the Company (including its subsidiaries), together with such
schedules prepared by the Responsible Officers and the Subsidiary Officers.

          6.   The Tower Data and Transmitter Data is compiled by the Subsidiary
Officers and Responsible Officers in a database managed by computer software
sufficiently capable of maintaining and manipulating such data.

          7.   The Tower Data and Transmitter Data is collected in the database
pursuant to established procedures for tracking the number of Towers owned,
leased, managed, licensed, marketed, shared pursuant to contract, or otherwise
utilized by or under the management of the Company, indicating (i) which
corporate entity of the Businesses exercises control over such Tower or
installed transmitter, (ii) the geographic location of such Tower or installed
transmitter and (iii) in the case of communications sites, the number of towers
located at such site and the status of such site (e.g., site identification,
acquisition, development, construction, commissioning or operational), and such
procedures include:

               (a)  in the case of Tower ownership, (1) each tower constructed
     by the Businesses is entered into the database at the time of commissioning
     of such tower and (2) each tower acquired by the Businesses, whether
     individually or in connection with the acquisition of a business that owns
     such tower, is entered into the database at the time of acquisition, and if
     any owned tower is sold to a third party not part of the Businesses, such
     tower is removed from the database at the time of such sale;

               (b)  in the case of Tower leasing or licensing, each tower,
     rooftop or communications site leased or licensed to the Businesses is
     entered into the database at the time the lease is executed or the license
     is granted, and removed from the database at the time the lease is
     terminated or license is revoked or terminated; and

               (c)  in the case of Tower management, marketing, sharing pursuant
     to contract or other utilization, each Tower managed, marketed, shared or
     utilized by the Businesses is entered into the database at the time the
     contract relating to such tower is executed and is removed from the
     database at the time the contract is terminated.

          8.   In preparing the Tower Revenue Statements, the undersigned (i)
participated in meetings and conversations with the Responsible Officers and the
Subsidiary Officers and (ii) examined the books and records of the Company
(including its subsidiaries), together with such schedules prepared by the
Responsible Officers and the Subsidiary Officers.

          9.   The Tower Revenue Statements were prepared by the Subsidiary
Officers and Responsible Officers based on the Tower Data and the Transmitter
Data and the Company's consolidated financial statements and the financial
statements of the subsidiaries of the Company.  The preparation of the Tower
Revenue Statements included:

                                       2

 
               (a)  in the case of owned towers, each Tower Revenue Statement
     states the actual gross revenue paid to the Company by all tenants and
     users of the relevant tower, rooftop or communication site during the
     period indicated (and unless specifically indicated otherwise in the
     Prospectus, all such Tower Revenue Statements measure actual gross revenue
     paid to the Company on a monthly basis); and

               (b)  in the case of tower leasing, licensing, management or
     marketing, each Tower Revenue Statement states the actual net income to the
     Company paid by all tenants and users of the relevant tower, rooftop or
     communication site during the period indicated (and unless specifically
     indicated otherwise in the Prospectus, all such Tower Revenue Statements
     measure actual net income paid to the Company on a monthly basis).

          10.  The Businesses are implementing procedures that will enable the
Company's independent auditors to verify the Tower Data, the Transmitter Data
and the Tower Revenue Statements.

          11.  The Population Coverage Statements are based on propagation
characteristics of the geographic area surrounding the broadcast transmission
sites and the range capability of the typical transmitters installed by the
Businesses at such sites; and to the knowledge of the undersigned after
reasonable inquiry with the Responsible Officers and the Subsidiary Officers,
such Population Coverage Statements or comparable coverage data have not been
contradicted by the Director General of the U.K. Office of Telecommunications or
any other relevant regulatory agency.

          12.  The undersigned hereby represents and warrants that the Tower
Data, Transmission Data, the Tower Revenue Statements and the Population
Coverage Statements presented in the Prospectus are true and accurate.  The
undersigned hereby further represents and warrants that the procedures outlined
above were undertaken by the Responsible Officers and the Subsidiary Officers
and that the compilation of the data that comprise the Tower Data, Transmission
Data, the Tower Revenue Statements and the Population Coverage Statements was
performed by the Responsible Officers and Subsidiary Officers in good faith and
using such judgment and is typically used by them in the management and
evaluation of the Company's operations.

          IN WITNESS WHEREOF, the undersigned has hereunto signed his name on
behalf of the Company this __ day of  August, 1998.

                                             By:________________________________
                                             Name:  Charles C. Green, III
                                             Title:  Chief Financial Officer

                                       3

 
                                  SCHEDULE I

          The Tower Data, Transmitter Data, Tower Revenue Statements and
Population Coverage Statements are principally located under the following
captions in the Prospectus:

 .    "Prospectus Summary--The Company"
 .    "Prospectus Summary--Background"
 .    "Prospectus Summary--Summary Unaudited Pro Forma Financial and Other Data"
     and the notes thereto
 .    "Prospectus Summary--Summary Financial and Other Data of CCIC" and the
     notes thereto
 .    "Prospectus Summary--Summary Financial and Other Data of CTI" and the notes
     thereto
 .    "Risk Factors--Risks Associated with Construction and Acquisition of
     Towers"
 .    "Risk Factors--Reliance on Significant Agreements"
 .    "Selected Financial and Other Data of CCIC" and the notes thereto
 .    "Selected Financial and Other Data of Crown"
 .    "Selected Financial and Other Data of CTI"
 .    "Management's Discussion and Analysis of Financial Condition and Results of
     Operations--Results of Operations"
 .    "Management's Discussion and Analysis of Financial Condition and Results of
     Operations--Liquidity and Capital Resources"
 .    "Industry Background--Trends in the Wireless Communications and
     Broadcasting Industries"
 .    "Business"
 .    "Business--Background"
 .    "Business--U.S. Operations"
 .    "Business--U.K. Operations"