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                                                                   EXHIBIT 10.23

               AMENDED AND RESTATED MASTER DESIGN BUILD AGREEMENT

     THIS AMENDED AND RESTATED MASTER DESIGN BUILD AGREEMENT ("AGREEMENT"),
dated as of the 21st day of March, 2000 is made by and between Texas
Telecommunications, L.P., a Texas limited partnership and Alamosa Wisconsin
Limited Partnership, a Wisconsin limited partnership (collectively, "CARRIER")
and SBA Towers, Inc., a Florida corporation ("BTS COMPANY").

     WHEREAS, Carrier and BTS Company entered into a Master Design Build
Agreement, dated as of February 22, 2000 (the "EXISTING MASTER DESIGN BUILD
AGREEMENT"); and

     WHEREAS, Carrier and BTS Company have agreed to amend and restate the
Existing Master Design Build Agreement to make certain changes, including the
addition of confidentiality provisions, on the terms and conditions set forth
herein;

     NOW, THEREFORE, in consideration of the mutual promises set forth herein,
the parties hereto agree that on the date set forth above, the Existing Master
Design Build Agreement shall be amended and restated in its entirety as follows:

                           I. RELATIONSHIP OF PARTIES

     1.1 INDEPENDENT CONTRACTOR RELATIONSHIP. The parties intend by this
Agreement to establish an independent contractor relationship. Neither party
nor their employees shall be agents or legal representatives of the other party
for any purpose. Neither party shall have the authority to act for, bind, or
commit the other party. BTS Company and Carrier agree that this Agreement does
not establish or create a relationship of employer-employee, principal-agent, or
a franchise, joint venture, or partnership for any purpose whatsoever.

     1.2 CONTRACTS WITH AFFILIATES. BTS Company may contract with any Affiliate
(as hereinafter defined) of BTS Company to provide goods or services beyond
those which its employees would perform, if it deems the same to be necessary or
advisable for development and/or construction of the Sites (as hereinafter
defined).

     1.3 LANDLORD AND TENANT RELATIONSHIP. BTS Company and Carrier have executed
the Master Site Agreement ("MSA"), dated as of February 22, 2000, which governs
the relationship of BTS Company, as landlord, and Carrier, as tenant, on those
BTS Sites (as hereinafter defined) which are accepted by Carrier pursuant to
SECTION 2.7(b) of this Agreement. A copy of the MSA is attached hereto as
EXHIBIT A. BTS Company and Carrier shall execute a Site Lease Agreement ("SLA")
with respect to each BTS Site in accordance with SECTION 2.7. The parties agree
to cooperate and act reasonably while performing under this Agreement, the MSA
and all SLAs.

     1.4 EXCLUSIVITY. During the term of this Agreement, BTS Company shall be
the exclusive build-to-suit service provider, site acquisition service provider,
line and antenna installation provider (except as to structural collocations
that are installed on a structure that is not a tower or in an instance where a
collocation tower owner requires the use of a designated contractor for
installation of Carrier's equipment on

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such tower), and construction company for wireless telecommunications tower
sites for Carrier and its Affiliates in the BTAs listed on SCHEDULE A attached
hereto and those BTAs agreed upon by the parties made subject to this Agreement
by amendment (the "APPLICABLE GEOGRAPHIC AREA"). For purposes of this Agreement,
"AFFILIATES" with respect to either party, shall mean companies which control,
are controlled by, or under common control with that party. For purposes of this
Agreement, the word "control" shall mean the ownership, directly or indirectly,
of the power to direct or cause the direction of the management and policies of
an entity, or the power to veto major policy decisions of any such entity,
whether through the ownership of voting securities, by contract or otherwise.
During the term of this Agreement, Carrier shall not engage any third party or
Affiliate directly or indirectly to perform build-to-suit, site acquisition,
construction, or equipment installation services in the Applicable Geographic
Area and will not enter into any discussions with any third party or Affiliate
concerning, or furnish any information relating to such services to any third
party or Affiliate, for the purpose of considering, soliciting or inducing any
offer by such third party.

     1.5 RESTRICTIONS ON SERVICES TO OTHERS. During the term of this Agreement,
BTS Company will not provide build-to-suit or site acquisition services for any
other person or entity in the BTAs that are subject to the exclusivity
restrictions set forth in SECTION 1.4, with the exception of (a) any of such
services being provided prior to the date of this Agreement and disclosed to
Carrier in SCHEDULE A attached hereto, and (b) any of such services commenced
after the date of this Agreement for which BTS Company has obtained the prior
approval of Carrier, such approval not to be unreasonably withheld.

                         II. SITE ACQUISITION SERVICES.

     2.1 SITE ACQUISITION SERVICES.

     (a) Carrier shall establish small geographic areas within the Applicable
Geographic Area within which a cell site or transmission tower shall be located,
based on the network grid's RF design (a "SEARCH RING"). For each Search Ring,
Carrier shall provide (i) minimum tower specifications, (ii) desired mounting
height, (iii) a description of the equipment that Carrier intends to put on the
tower, including any expansion plans, and (iv) any other technical data
reasonably necessary to permit SBA to effectively identify the candidate sites
that meet Carrier's needs. Carrier will provide to BTS Company its system
network grid, with the established Search Rings overlaid thereon. Carrier will
from time to time, assign Search Rings to BTS Company. BTS Company shall provide
the personnel and facilities which are necessary to locate and lease or license
existing towers, buildings or other structures by Carrier to be used for the
installation of Carrier's equipment ("COLLOCATION SITES") or locate and lease,
license or purchase unimproved real property suitable for the construction and
installation of a communications tower and related facilities by BTS Company
("BTS SITE") and the installation of Carrier's equipment. As used herein,
"SITES" shall refer to both Collocation Sites and BTS Sites. BTS Company shall
perform site acquisition services with respect to each Search Ring in accordance
with the scope of work attached hereto as SCHEDULE B ("SITE ACQUISITION
SERVICES"). BTS Company shall be entitled to compensation from Carrier for the
Site Acquisition Services performed on Collocation Sites as set forth on
SCHEDULE D attached hereto. BTS Company shall be entitled to compensation from
Carrier for the Site Acquisition Services performed on BTS Sites under SECTIONS
2.2, 2.3, 2.4(c), 2.4(f) AND 2.7(c) as set forth on SCHEDULE D attached hereto.
BTS Company hereby acknowledges that Carrier maintains a preference to fulfill
its needs for wireless communications installations via suitable Collocation
Sites that may be available within the respective Search Rings designated
hereunder. In the performance of the Site Acquisition Services, BTS Company
shall use diligent and good faith efforts to maximize collocation opportunities
as a primary responsibility, with BTS Sites to be a secondary fulfillment of
Carrier's needs.

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     (b) Upon receipt of a Search Ring designated hereunder by Carrier, BTS
Company shall promptly, diligently and professionally perform the Site
Acquisition Services with respect to such Search Ring in accordance with this
Agreement, including, without limitation, the objectives and procedures set
forth in SCHEDULE B attached hereto ("OBJECTIVES AND PROCEDURES").

     (c) Except as expressly authorized in this Agreement or otherwise expressly
authorized by Carrier in writing, BTS Company shall provide all labor,
equipment, material and supplies necessary or appropriate to perform Site
Acquisition Services.

     (d) During the performance of Site Acquisition Services with respect to any
designated Search Ring, BTS Company shall at all times apprise Carrier of any
expressed opposition, protest, litigation or other efforts, whether by an
individual, group, neighborhood association or other organization, to restrict,
alter or prohibit the construction, installation or operation of any structure,
structures or other facilities that Carrier or BTS Company proposes to construct
or operate on any Site within such Search Ring.

     2.2 WITHDRAWAL OF SITE. In the event Carrier elects to withdraw a
Collocation Site at any time or a BTS Site pursuant to the terms of this
Agreement, Carrier shall give BTS Company notice of such withdrawal. In the
event that the withdrawn Site is a Collocation Site, Carrier shall pay BTS
Company 50% of the milestone installment that would be due if the work currently
in progress was completed, 100% of the reimbursable costs which were incurred
prior to the date on which BTS Company receives notice of the withdrawn Site,
and 100% of all other amounts due hereunder for work completed on the Site as of
the date BTS Company receives Carrier's withdrawal notice and shall substitute
the withdrawn Site with an alternative Site or Search Ring within sixty (60)
days ("ALTERNATIVE SITE"), if available. In the event that a withdrawn Site is a
BTS Site, Carrier shall pay BTS Company for the Services (as hereinafter
defined), except where BTS Company otherwise so chooses to develop such BTS Site
for its own purposes, including, without limitation, Site Acquisition Services,
in connection with such Site in the same percentage as though such site was a
Collocation Site using the milestones and amounts set forth in SECTION B(1)(b)
of SCHEDULE D attached hereto. Notwithstanding anything to the contrary
contained in this Agreement, in the event that Carrier rejects or withdraws a
Site due to the Carrier's reasonable conclusion based upon the Carrier's due
diligence pursuant to Section 2.7(b)(v), that there is a material defect
existing with respect to the Site that will materially adversely affect
Carrier's use of the Site as contemplated under this Agreement, then Carrier
shall only be obligated to reimburse BTS Company for third party services in
connection with the withdrawn or rejected Site.

     2.3 SEARCH RINGS DESIGN. Carrier shall have the right at any time in its
sole and absolute discretion to expand or reconfigure a previously designated
Search Ring. In the event that Carrier redesigns a Search Ring for a Collocation
Site beyond 0.5 miles of an urban or suburban Site or 1.5 miles of a rural Site
for which BTS Company has begun but not yet completed all Site Acquisition
Services, then Carrier shall pay BTS Company 100% for all Site Acquisition
Services completed at the time that the notice of redesign is received by BTS
Company, 100% of the reimbursable costs which were incurred prior to the date on
which BTS Company receives notice of such reconfigured Search Ring, and 50% of
the milestone installment that would be due if the work currently in progress
was completed. In the event that such Search Ring was a BTS Site, Carrier shall
pay BTS Company for such Site Acquisition Services in connection with the
original Search Ring in the same percentage as though such site was a
Collocation Site using the milestones and amounts set forth in SECTION B(1)(b)
of SCHEDULE D attached hereto. For all Site Acquisition Services rendered for
the redesigned search ring, in the event that the Site in the redesigned Search
Ring is a Collocation Site, Carrier shall pay BTS Company 100% for all
milestones performed and 100% of the reimbursable costs which are incurred.
Carrier agrees not to develop any site within any withdrawn Search

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Rings or an original Search Ring which has been subsequently redesigned as a
tower site and each party hereto further agrees not to transfer the associated
Work Product to any third party, including Affiliates

     2.4 TERM OF SITE ACQUISITION SERVICES AGREEMENT; DEFAULT.

     (a) The term of this Agreement (the "Site Acquisition Term") commenced as
of February 22, 2000 and shall expire on December 31, 2001.

     (b) A party shall be in default under this Agreement with respect to a Site
or a Search Ring if such party breaches an obligation or covenant under this
Agreement to be performed with respect to that Search Ring or Site, which breach
is not cured within thirty (30) days after the breaching party's receipt of
written notice; provided, however, that so long as the defaulting party
commenced appropriate curative action within such thirty (30) day period, and
thereafter diligently prosecutes such cure to completion as promptly as
possible, the cure period will be extended until the cure is completed.

     (c) If BTS Company is in default under this Agreement with respect to a
Site or Search Ring, Carrier shall have the right to terminate this Agreement as
to the applicable Site or Search Ring only. In the event of such a termination,
Carrier shall have the right to terminate BTS Company's right to complete the
Services with respect to the Site or Search Ring subject to the default, and
Carrier shall have the right to complete or engage a third party to complete
such Services.

     (d) If Carrier is in default under this Agreement with respect to a Site or
Search Ring, BTS Company shall have the right to terminate this Agreement as to
the applicable Site or Search Ring only.

     (e) Neither a termination as to any particular Search Ring or Site, nor the
expiration of this Agreement shall affect:

               (i) the terms of the MSA or any SLA as such agreements affect any
          Site or Search Ring not subject to a default, which has been entered
          into by the parties prior to the date of termination of this Agreement
          as to any particular Search Ring or Site, which shall continue in
          accordance with its terms and conditions;

               (ii) the terms of this Agreement that apply to any SLA which has
          been entered into by the parties prior to the date of termination of
          this Agreement and is not subject to a default;

               (iii) any duties or obligations for payment or performance that
          are or become owing hereunder prior to the effective date of such
          termination;

               (iv) the terms of this Agreement that apply to any Search Ring
          which was issued prior to the date of termination of this Agreement
          that is not the subject of a default; or

               (v) any other duties or obligations that expressly survive the
          termination or expiration hereof.

     (f) A default regarding one Search Ring or Site shall not constitute a
default under this Agreement or with respect to any other Search Ring or Site.
Notwithstanding the previous sentence, in the event that BTS Company is in
default with respect to the greater of (i) fifteen (15) Search Rings in a BTA,
or (ii) twenty percent (20%) or more of the Search Rings issued in such BTA, BTS
Company's right to provide exclusive services under SECTION 1.4 shall terminate
with respect to the BTA subject to such defaults. Upon

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such termination, BTS Company's obligation to provide exclusive Services under
SECTION 1.5 in such BTA shall terminate. BTS Company's and Carrier's rights and
obligations with respect to the Sites and Search Rings subject to the default
shall be governed by SECTION 2.4(c). With respect to Search Rings issued in the
BTA subject to the default after BTS Company's exclusivity rights have
terminated, Carrier shall have the right to perform the Services or to engage a
third party to perform the Services with the exception of the construction
services described in the next sentence. Notwithstanding the termination of BTS
Company's rights of exclusivity under SECTION 1.4 with respect to a BTA subject
to a default described in the second sentence of this section and provided that
BTS Company is not in default with respect to the Construction Management
Services or construction scope of work or deliverable work product, BTS Company
shall have the right to construct the Tower Facilities (as hereinafter defined)
and perform the Construction Management Services with respect to BTS Sites, and
may perform Carrier Installation Services with respect to such BTS Sites upon
Carrier's request on a Site resulting from Search Rings issued in the BTA
subject to the default after BTS Company's rights of exclusivity under SECTION
1.4 are terminated. BTS Company shall be paid for those Services pursuant to the
terms of this Agreement. With respect to all Search Rings issued in a BTA
subject to a default described in the second sentence of this section after the
termination of BTS Company's rights of exclusivity under SECTION 1.4, Provided
that the Services that were not performed by BTS Company with respect to such a
BTS Site are performed to the satisfaction of BTS Company, Carrier shall convey
the Tower Facilities and any site development material not subject to
confidentiality requirements, including, without limitation, ground leases,
title reports, environmental reports and geotechnical reports to BTS Company
upon completion of the Services with respect to such Search Ring lien free
pursuant to assignment documentation reasonably acceptable to both parties, and
BTS Company shall reimburse Carrier for the reasonable costs of completing the
Services, provided that Carrier provides BTS Company with reasonable
substantiation for such costs. BTS Company and Carrier shall execute an SLA for
the applicable Site simultaneously with the conveyance of the site development
material and such Site shall be subject to the terms of the MSA as though BTS
Company had completed all of the Services for such Site.

     2.5 GROUND LEASES. The acquisition of BTS Sites by BTS Company pursuant to
this Agreement shall be accomplished by BTS Company purchasing the BTS Site or
leasing the BTS Site using a lease agreement between BTS Company and the lessor
(hereafter the "GROUND LEASE") as approved by Carrier or Carrier's authorized
representatives in accordance with SECTION 2.7(b)(v). The acquisition of
Collocation Sites by BTS Company pursuant to this Agreement shall be
accomplished using a lease agreement between Carrier and the lessor, which
Carrier shall provide to BTS Company or on such other form which Carrier may, in
its sole discretion, approve.

     2.6. ACCEPTANCE AND REJECTION OF COLLOCATION SITES. Carrier may at any time
in its sole and absolute discretion accept or reject any proposed Collocation
Site. Without limiting the foregoing, Carrier may withdraw its prior acceptance
of a Collocation Site and thereby reject such Collocation Site. A withdrawal or
any rejection by Carrier of a Collocation Site shall not affect its obligation
for fees earned through the date of termination for Site Acquisition Services as
more particularly described in SECTION 2.2.

     2.7 ACCEPTANCE AND REJECTION OF BTS SITES; EXECUTION AND DELIVERY OF SLAS

     (a) A BTS Site shall be deemed to be an accepted BTS Site from and after
the date that the Candidate Site which corresponds to the BTS Site has been
approved by Carrier pursuant to SECTION 2(a) of SCHEDULE B attached hereto and
shall continue to be deemed an accepted BTS Site unless and until Carrier
rejects the BTS Site pursuant to SECTION 2.7(b) hereof or Carrier terminates the
applicable SLA pursuant to the terms of the MSA.

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     (b) Carrier may at any time prior to the parties' execution and delivery of
an SLA corresponding thereto, and in Carrier's sole and absolute discretion,
reject any BTS Site. In the case of a BTS Site that is accepted by Carrier, the
following shall apply:

               (i) BTS Company shall continue the diligent, thorough and
          professional prosecution of Site Acquisition Services (including the
          completion of Ground Lease negotiations and required zoning, land use
          and permitting matters) necessary for the construction of a
          communications tower and related facilities consistent with the
          criteria theretofore identified by Carrier;

               (ii) Subject to SECTION 2.7(b)(iii) below, BTS Company and
          Carrier shall prepare and finalize the SLA (and exhibits thereto)
          applicable to such BTS Site;

               (iii) Within ten (10) days following Carrier's notice from BTS
          Company that BTS Company has received all necessary zoning or other
          land use permits or approvals applicable to the improvements to be
          constructed by BTS Company on the BTS Site and the completion of Site
          Acquisition Services in accordance with the Objectives and Procedures,
          but subject to SECTION 2.7(b)(iv) below, BTS Company shall prepare an
          SLA for such BTS Site, Carrier shall provide to BTS Company all
          information reasonably requested by BTS Company to enable BTS Company
          to prepare the SLA and Carrier and BTS Company shall execute and
          deliver the SLA applicable thereto. Upon the full execution of an SLA,
          BTS Company shall thereafter perform its obligations thereunder in
          accordance with the SLA and this Agreement. Notwithstanding any
          provision of this Agreement to the contrary, in the event that Carrier
          neither accepts nor rejects the BTS Site within ten (10) days as
          provided herein, but subject to SECTIONS 2.7(b)(iv) AND 2.7(b)(v)
          below, BTS Company may, at BTS Company's sole option either (A) deem
          the BTS Site approved (in which event BTS Company shall be entitled to
          compel Carrier to execute a SLA with respect to the BTS Site or
          execute the SLA on behalf of Carrier) or (B) deem the BTS Site to be
          rejected and make demand on Carrier for payment of the fees earned for
          Site Acquisition Services.

               (iv) Carrier may in its sole and absolute discretion withdraw its
          prior acceptance of a BTS Site, and thereby reject said BTS Site, at
          any time prior to the BTS Company parties' execution and delivery of
          the SLA for such BTS Site, subject to Carrier's right to terminate an
          SLA pursuant to the MSA.

               (v) Notwithstanding anything to the contrary contained in this
          Agreement, in the event that Carrier's due diligence investigation or
          review of BTS Company's due diligence investigation with respect to a
          Site causes Carrier to reasonably believe that Carrier's use and
          occupancy of the Site would be adversely affected as a result of such
          review, Carrier shall have the right through its legal counsel to
          reject such Site by providing BTS Company with notice prior to BTS
          Company's commencement of construction at the Site, but no later than
          within thirty (30) days of Carrier's receipt of notice from BTS
          Company that BTS Company has provided Carrier with all documentation
          required pursuant to this Agreement. It further being agreed and
          acknowledged that no SLA shall be executed or construction commenced
          until such time as BTS Company has received Carrier's approval as
          required under this paragraph, provided, however, that Carrier and
          Carrier's counsel's failure to respond within such thirty (30) day
          period shall be deemed an approval.

     (c) In the event of a rejection by Carrier of a BTS Site, including a
rejection after a prior acceptance thereof (except as specified in the last
sentence of Section 2.2) as described above in SECTION 2.7(b) hereof, Carrier
shall be obligated for the payment to BTS Company for Site Acquisition Services

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incurred prior to such rejection with respect to the Search Ring containing such
BTS Site in accordance with SECTION 2.2. In the event of such a rejection,
Carrier agrees not to develop the rejected BTS Site as a tower site and further
agrees not to transfer the associated Work Product to any third party, including
Affiliates.

     (d) In the event of a rejection by Carrier of a BTS Site, BTS Company may
elect to forego the compensation set forth in SECTION 2.2 and retain the Work
Product.

     (e) In the event that BTS Company's due diligence investigation of a BTS
Site reveals any defect in such site which BTS Company reasonably believes would
materially adversely affect BTS Company's use or ownership of such BTS Site, or
would limit BTS Company's ability to lease space on the applicable Tower to one
broad band tenant, BTS Company shall be entitled to reject such Site upon notice
to Carrier. In such event, Carrier shall have the right to designate another
candidate site as the preferred candidate. BTS Company shall bear all costs
associated with Site Acquisition Activities and all costs associated with the
due diligence investigation, zoning, and permitting of such Site.

     2.8 CONTINUED PERFORMANCE OF SITE ACQUISITION SERVICES FOLLOWING SITE
ACCEPTANCE OR REJECTION. Unless otherwise notified by Carrier, BTS Company
shall:

     (a) Following Carrier's acceptance of any Site, continue to perform Site
Acquisition Services with respect to such accepted Site in accordance with this
Agreement, including, without limitation, the Objectives and Procedures; and

     (b) Following Carrier's rejection of any Site (including a rejection after
Carrier's prior acceptance thereof), continue to perform Site Acquisition
Services with respect to the Search Ring pertaining thereto (including a
modified Search Ring as described above in SECTION 2.3 hereof) in accordance
with the terms and conditions of this Agreement, including, without limitation,
the Objectives and Procedures.

     2.9 COMPLIANCE WITH LAWS. BTS Company represents and warrants that it
shall: (a) comply with all federal, state and local laws, regulations and
ordinances with respect to its performance of the Site Acquisition Services; (b)
file all reports relating to the Site Acquisition Services and required under
applicable law (including, without limitation, tax returns); (c) pay all filing
fees and federal, state and local taxes applicable to BTS Company's business as
the same shall become due; and (d) pay all amounts required under local, state
and federal workers' compensation, disability benefit, unemployment insurance,
and other employee benefit laws and regulations when due. BTS Company shall
provide Carrier with such documents and other supporting materials as Carrier
may reasonably request to evidence BTS Company's continuing compliance with this
SECTION 2.9.

     2.10 INSURANCE. BTS Company and Carrier shall each maintain in effect,
without interruption, on an annual basis, during the term of this Agreement, the
following insurance policies:

          (a) Commercial General Liability (Bodily Injury and Property Damage).
     Insurance coverage with endorsement evidencing coverage for contractual
     liability. The limits of this insurance shall not be less than:

               (i) Each Occurrence Limit $1,000,000

               (ii) General Aggregate Limit $2,000,000

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          (b) Comprehensive Automobile Liability insurance covering the
     ownership, operation and maintenance of allowed, non-owed, and hired motor
     vehicles, in limits not less than $1,000,000 for bodily injury and property
     damage per occurrence.

          (c) Worker's Compensation Insurance with statutory limits and
     Employer's Liability Insurance with limits of not less than $1,000,00 for
     each accident.

          (d) Professional Liability (errors and omissions) insurance of not
     less than $1,000,000 for each occurrence, with endorsement evidencing
     coverage for contractual liability.

          (e) All foregoing insurance shall provide for an effective date no
     later than February 22, 2000. Carrier and BTS Company agrees to maintain
     such coverage in effect without interruption on an annual basis for so long
     as this Agreement is in effect. Carrier shall be included as an additional
     insured on BTS Company's Commercial General Liability insurance, and BTS
     Company shall be included as an additional insured on Carrier's Commercial
     General Liability insurance. Carrier and BTS Company agree to obtain such
     insurance from nationally recognized carriers at commercially reasonable
     rates. Carrier's and BTS Company's obligations under this Agreement,
     including its indemnification obligations under SECTION 2.11, will not be
     affected by obtaining or the failure to obtain any insurance coverage
     required under this SECTION 2.10.

          (f) Carrier and BTS Company shall each provide the other with
     Certificates of Insurance from its insurance agent or broker or insurance
     company evidencing the above coverage and limits.

          (g) All insurance policies required to be maintained hereunder shall
     be issued by companies that hold a current rating of not less than "A",
     according to Best Key Rating Guide, unless this requirement is expressly
     waived in writing by the other party.

     2.11 INDEMNIFICATION. The following indemnities shall survive the
expiration or termination of this Agreement:

     (a) By Carrier. Carrier shall indemnify, defend and hold harmless BTS
Company, its Affiliates, directors, officers, shareholders, agents, and
employees thereof from and against any fine, penalty, loss, cost, damage,
injury, claim, expense (including reasonable attorney and other professional
fees and costs and all reasonable fees and costs associated with enforcing this
indemnification), or liability incurred by BTS Company as the result of (i) any
breach of Carrier's obligations under this Agreement, or (ii) the negligence or
intentional misconduct of Carrier arising directly out of the performance of
this Agreement, including any election by Carrier to pursue certain rights under
this Agreement.

     (b) By BTS Company. BTS Company shall indemnify, defend and hold harmless
Carrier, its Affiliates, directors, officers, shareholders, agents, and
employees thereof from and against any fine, penalty, loss, cost, damage,
injury, claim, expense (including reasonable attorney and other professional
fees and costs and all reasonable fees and costs associated with enforcing this
indemnification), or liability incurred by Carrier as the result of (i) any
breach of BTS Company's obligations under this Agreement, or (ii) the negligence
or intentional misconduct of BTS Company arising directly out of the performance
of this Agreement, including any election by BTS Company to pursue certain
rights under this Agreement.

     (c) NOTWITHSTANDING ANYTHING TO THE CONTRARY CONTAINED IN THIS SECTION
2.11, THE INDEMNITY OBLIGATIONS OF EITHER PARTY HERETO WILL NOT APPLY

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TO ANY INJURY, LOSS, DAMAGE, LIABILITY, PENALTY OR OBLIGATION (OR ANY CLAIM IN
RESPECT OF THE FOREGOING) RESULTING FROM THE NEGLIGENCE OR INTENTIONAL
MISCONDUCT OF THE OTHER PARTY HERETO OR OF SUCH OTHER PARTY'S AGENTS, EMPLOYEES
OR CONTRACTORS. TO THE FULLEST EXTENT PERMITTED BY LAW, ALL CLAIMS AGAINST THE
OTHER PARTY FOR LOST PROFITS OR EARNINGS OR OTHER INDIRECT OR CONSEQUENTIAL
DAMAGES OTHERWISE RECOVERABLE UNDER APPLICABLE LAW AS A RESULT OF THE BREACH OF
THIS AGREEMENT OR OTHERWISE PURSUANT TO THE FOREGOING INDEMNITY PROVISIONS ARE
HEREBY WAIVED BY THE AGGRIEVED PARTY.

     (d) Notwithstanding anything to the contrary contained in this Agreement,
the terms and conditions of this SECTION 2.11 shall survive the termination or
expiration of this Agreement for a one (1) year period.

     2.12 ASSIGNMENT. The rights of the parties under this Agreement are
personal and may not be assigned without the prior written consent of the other
party, except that either party (a) may delegate any of its obligations
hereunder to any Affiliates thereof and assign any rights relating thereto to
such Affiliates without the prior written consent of the other, provided that
such delegation or assignment shall not relieve or release the delegating party
from any obligations hereunder, (b) may assign this Agreement without the prior
written consent of the other to any entity by way of merger, consolidation or
other reorganization, (c) may assign this Agreement without the prior written
consent of the other party to any entity acquiring all or substantially all of
the other party's assets, so long as the acquiring party is reputable entity in
the same business as the party being whose assets are being acquired and agrees
to assume the obligations of the party whose assets are being acquired, and (d)
as collateral in connection with financing. The prohibition against assignment
contained in this SECTION 2.12 shall not prohibit BTS Company from
subcontracting portions of its work under this Agreement.

       III. DESIGN AND CONSTRUCTION OF WIRELESS COMMUNICATIONS FACILITIES

     3.1 CONSTRUCTION OBLIGATIONS.

     (a) At each Collocation Site, except for those structural Collocation Sites
noted in SECTION 1.4, BTS Company shall perform the construction management
services set forth in SECTION 1 of SCHEDULE C attached hereto ("CONSTRUCTION
MANAGEMENT SERVICES") and the Carrier Equipment (as hereinafter defined)
installation services set forth in SECTION 2 of SCHEDULE C attached hereto
("CARRIER EQUIPMENT INSTALLATION SERVICES"). As part of the Carrier Equipment
Installation Services, BTS Company will install Carrier's Equipment to agreed
upon specifications, perform sweep tests and document results meeting or
exceeding Carrier's standards and set Carrier's BTS equipment and connect to
grounding system. As part of the Carrier Equipment Installation Services, BTS
Company shall also provide conduit for electrical and telephone connections from
the central demarcation point to Carrier's BTS Equipment location and will pull
coaxial cables into the "doghouse" and install jumpers. Carrier shall be
responsible for connecting power, telephone and coaxial cable jumpers to
Carrier's BTS equipment.

     (b) At each BTS Site, BTS Company shall perform the Construction Management
Services and the Carrier Equipment Installation Services. At each BTS Site, BTS
Company shall also be responsible for constructing the towers, fencing,
grounding systems, power and telephone connections to a central demarcation
point within the tower compound, and a concrete equipment pad as specified by
site diagrams

                                       9
<PAGE>   10

for Carrier's Equipment (the "TOWER FACILITIES"; the Site Acquisition Services,
the Construction Management Services, the Carrier Equipment Installation
Services and the construction of the Tower Facilities shall be referred to
collectively as the "SERVICES"). BTS Company shall act with due diligence to
construct the Tower Facilities at minimum in accordance with Carrier's minimum
specifications provided to BTS Company in the applicable Search Ring. BTS
Company shall use due diligence to obtain all necessary permits and approval of
the plans and specifications from all applicable governmental agencies.

     3.2 CHANGE ORDERS. Carrier shall have the right to issue reasonable change
orders to BTS Company on any given Site provided that such changes are tendered
to BTS Company in writing and that Carrier pays the increase in the cost of
construction of the Tower Facilities attributable to such change orders, and
further that BTS Company shall credit Carrier with any decrease in cost due to
such change order, but in no event shall any change order have the effect of
limiting the intended use of such Site by either party.

     3.3 CONSTRUCTION COSTS AND PAYMENTS.

     (a) Except as otherwise expressly authorized in this Agreement, BTS Company
shall be responsible for the payment of all costs associated with the
Construction Management Services, the Carrier Equipment Installation Services
and the costs of constructing the Tower Facilities. Notwithstanding anything to
the contrary contained in this Agreement, BTS Company shall not be responsible
for the cost of Carrier's Equipment. Carrier shall be responsible for the cost
of purchasing, insurance and delivery of the Carrier's Equipment to each Site by
the date required by BTS Company, and all associated costs. As used herein,
"CARRIER'S EQUIPMENT" shall mean all antennas, microwave antennas, icebridge,
GPS antennas, miscellaneous hardware, coaxial cable, jumpers, connectors,
waterproof kits, hoisting grips, mounting brackets, generators, battery backup
kits, BTS equipment and BTS mounting platforms or equipment, or any costs
associated with the delivery or installation thereof.

     (b) Carrier shall pay BTS Company for the Construction Management Services
and Carrier Equipment Installation Services performed at Collocation Sites in
accordance with SECTIONS B(2) and (3) of SCHEDULE D attached hereto.

     (c) Carrier shall pay BTS Company for the Construction Management Services
and Carrier Equipment Installation Services performed at BTS Sites in accordance
with SECTIONS B(2) and (3) of SCHEDULE D attached hereto. BTS Company shall be
solely responsible for the costs associated with the construction of the Tower
Facilities on each BTS Site. Notwithstanding the previous sentence, Carrier
shall pay for all costs incurred exceeding $40,000 in connection with the
provision of appropriate utilities and/or access to a BTS Site in the form of a
lump sum payment or as an increase in Rent (as defined in the MSA) in the amount
of $18 for each $1,000 (or portion thereof) increment exceeding $40,000. In the
event that BTS Company determines that the cost to provide the appropriate
utilities and access to a BTS Site will exceed $40,000, BTS Company shall notify
Carrier of the estimated cost. Carrier will have ten (10) days from receipt of
BTS Company's notice to notify BTS Company which payment option Carrier elects.
If Carrier fails to give BTS Company such notice within the ten (10) day period,
Carrier will be deemed to have chosen to make the payment in a lump sum. Upon
completion of access and utilities at a BTS Site, BTS Company shall notify
Carrier of the amount by which the provision of access and utilities to the
applicable BTS Site exceeded $40,000. In the event that Carrier had previously
given notice, or is deemed to have given notice, that Carrier will pay the
excess in a lump sum, Carrier shall make the payment requested within 30 days of
receipt of the notice. In the event Carrier had previously given notice that
Carrier will pay the excess with an increase in Rent, the parties will amend the
applicable SLA within ten (10) days of Carrier's receipt of the notice to
provide for the Rent increase.

                                       10
<PAGE>   11

     3.4 COMMENCEMENT OF CONSTRUCTION.

     (a) BTS Company shall make reasonable and diligent efforts to complete the
construction of an individual Tower Facility within thirty (30) days after
Carrier executes an SLA for the Site upon which the Tower Facilities are to be
constructed, subject to Excusable Delays. For purposes of this Agreement,
"EXCUSABLE DELAYS" shall mean any circumstances beyond BTS Company's reasonable
control to the extent they delay BTS Company in the performance of BTS Company's
duties and obligations under this Agreement in respect of a Site, including,
without limitation, (a) condemnation or other exercise of the power of eminent
domain, (b) changes in applicable government requirements, the orders of any
governmental authority having jurisdiction over a party, (c) acts of God,
including, without limitation, tornadoes, hurricanes, floods, sinkholes,
landslides, earthquakes, epidemics, quarantine and pestilence; (d) fire and
other casualties, such as explosions and accidents, (e) acts of a public enemy,
acts of war, terrorism, effects of nuclear radiation, blockades, insurrections,
riots, civil disturbances or national or international calamities; (f) adverse
weather conditions, (g) delays in obtaining utility services, so long as BTS
Company is using commercially reasonable efforts to obtain such utility
services, (h) strikes, walkouts, labor disputes or other third party events or
conditions which materially and adversely affect BTS Company's ability to
complete the Site, (i) delays caused by Carrier, and (j) governmental action or
inaction not caused by the action or inaction of BTS Company. BTS Company shall
have no obligation to commence construction of the Tower Facility at a BTS Site
unless and until an SLA has been properly executed by Carrier for that Site.

     (b) In the event that BTS Company fails to complete construction of the
Tower Facilities within fifteen (15) days of the date which is thirty (30) days
after execution of an SLA, as extended for each day that completion is delayed
as a result of an Excusable Delay, BTS Company shall pay to Carrier as
liquidated damages the sum of One Thousand and No/100 Dollars ($1,000) per week
for each week that the Tower Facility has not been completed after such date.
These liquidated damages shall be Carrier's sole remedy in the event that BTS
Company fails to meet a construction deadline in connection with the Tower
Facilities.

     3.5 MANNER OF CONSTRUCTION. BTS Company represents, warrants and agrees
that the Tower Facilities shall be constructed in a good and workmanlike manner
and at a minimum in accordance with Carrier's minimum specifications and all
applicable federal, state and local laws, ordinances, rules and regulations. BTS
Company warrants to Carrier that all materials furnished in connection with the
construction of the Tower Facilities will be new unless otherwise specified, and
that such construction will be of good quality in accordance with industry
standards, free from faults and patent defects. The warranties contained in this
SECTION 3.5 shall run for a period of twelve (12) months from the SLA
Commencement Date, as defined in the MSA.

     3.6 NO LIENS. BTS Company shall keep the Tower Facilities free of all liens
and claims arising out of or related to the performance of the construction, all
liens and claims of any contractor, subcontractor, laborer, mechanic or
materialman for labor performed or material furnished in connection with the
performance of the construction. In the event any such lien is recorded against
the Site, the BTS Company shall, within forty-five (45) days after its receipt
of notice that such a lien has been recorded, either (a) have such lien released
of record, or (b) deliver to Carrier a bond, in form, content and amount, and
issued by a surety, reasonably satisfactory to Carrier, indemnifying Carrier
against all costs and liabilities resulting from such lien.

     3.7 PROGRAM MANAGEMENT SERVICES. In connection its provision of the
Services pursuant to this Agreement, BTS Company shall:

                                       11
<PAGE>   12

     (a) Develop and implement a quality assurance program, which ensures that
all activities are performed to industry standard quality standards.

     (b) Hold weekly progress meetings with Carrier for planning purposes and
monitoring compliance with this Agreement. BTS Company will provide Carrier with
a weekly tracking report.

     (b) Manage and coordinate interaction among site acquisition, construction,
management, and the A&E firm.

     (c) Manage and coordinate interactions between the infrastructure
development staff (site acquisition and construction management) and other
disciplines involved in the system deployment (e.g., RF engineering, network
engineering, marketing).

     3.8 NOTIFICATION OF COMPLETION OF A BTS SITE. BTS Company shall notify
Carrier of: the date when the Tower Facilities have been substantially completed
on a BTS Site ("NOTICE OF COMPLETION"). Within ten (10) business days after the
Notice of Completion, Carrier shall deliver to BTS Company a list of items
("PUNCH LIST") that Carrier deems necessary that BTS Company complete or correct
in order for the Tower Facilities to be completed in accordance with Carrier's
minimum specifications for the applicable Search Ring. The Tower Facilities
shall be deemed accepted by Carrier if a Punch List is not received by BTS
Company within ten (10) business days of the date of Notice of Completion. In
the event that Carrier delivers a Punch List to BTS Company, the notification
process set forth in this section shall be iterated until the Tower Facilities
have been completed in accordance with Carrier's minimum specifications for the
applicable Search Ring and any approved Change Orders.

     3.9 BTS COMPANY PERSONNEL. Carrier reserves the right to require from BTS
Company the immediate removal from or to exclude any person or entity employed
by or working for BTS Company from any Site, in Carrier's reasonable judgment,
but only if the exercise thereof if a commercially reasonable procedure under
the circumstances, who in Carrier's reasonable opinion (i) engages in any
misconduct, (ii) is incompetent, or (iii) is negligent in the performance of
his, her or its duties.

                  IV. REPRESENTATIONS, WARRANTIES AND COVENANTS

     4.1 MUTUAL REPRESENTATIONS, WARRANTIES AND COVENANTS. Each party represents
and warrants to the other party, which representations and warranties shall
continue for the term of the Agreement and the consummation of the transactions
herein contemplated, that:

     (a) it has full power and authority to execute and perform under this
     Agreement;

     (b) the execution, delivery and performance of the Agreement have been duly
     authorized by all necessary action on the part of such party and the
     Agreement is binding and enforceable against such party in accordance with
     its terms;

     The parties covenant and agree to use their best efforts to cooperate with
each other in the performance of their respective obligations under the
Agreement, and to take no action that will interfere with the performance by the
other party of such obligations.

     4.2 BTS COMPANY'S REPRESENTATIONS, WARRANTIES, AND COVENANTS.

                                       12
<PAGE>   13

     (a) BTS Company represents and warrants that BTS Company is a corporation
duly organized, validly existing, and in good standing under the laws of the
State of Florida and that, as of February 22, 2000, it was qualified to do
business in and was in good standing under the laws of the following states:
Arizona, California, Colorado, New Mexico, Texas and Wisconsin.

     (b) BTS Company represents and warrants that BTS Company shall perform the
Services in accordance with the current standards of care and diligence normally
practiced by recognized firms performing services of a similar nature.

     (c) BTS Company shall comply with all local, municipal, state, federal, and
governmental laws, orders, codes, and regulations applicable to BTS Company's
provision of the Services. BTS Company has all necessary licenses to perform the
Services.

     4.3 CARRIER'S REPRESENTATIONS, WARRANTIES AND COVENANTS.

     (a) Carrier represents and warrants that all information which it shall
provide to BTS Company in connection with BTS Company's performance of its
obligations hereunder shall be true and complete in all material respects.

     (b) Carrier covenants that, in a timely fashion, it shall provide all
information which BTS Company reasonably requests, is not otherwise freely
available to BTS Company and is deemed necessary or desirable by BTS Company in
the course of its provision of its obligations hereunder, including, but not
limited to, information to be supplied in connection with the zoning, permitting
or construction process.

     (c) Carrier represents and warrants that Carrier is a limited partnership
duly organized, validly existing and in good standing under the laws of the
State of Texas and as of February 22, 2000, was qualified to do business in and
was in good standing under the laws of the following states: Arizona,
California, Colorado, New Mexico, Texas and Wisconsin.

     4.4 CONFIDENTIAL INFORMATION. BTS Company and Carrier agree that the
subject matter and the terms of the Existing Master Design Build Agreement, the
MSA and this Agreement shall be confidential and shall not be disclosed except:

     (a) with the other party's prior written consent;

     (b) to a party's attorneys and other third party consultants, provided that
such third parties shall be subject to the terms of this SECTION 4.4;

     (c) in defense of a legal action;

     (d) to the extent required by law or as necessary in connection with
government filings, provided, however that the financial terms of the agreements
shall be redacted or given confidentiality treatment;

     (e) to the extent lawfully received from another source free of restriction
and without breach of this Agreement;

     (f) that becomes generally available to the public without breach of this
Agreement;

                                       13
<PAGE>   14

     (g) is obligated to be produced by order of a court of competent
jurisdiction, provided that the party subject to such order shall make
reasonable efforts not to disclose the financial terms of the agreements;

     (h.) known to the receiving party at the time of disclosure;

     (i.) independently developed by the receiving party without resort to
confidential information; and

     (j.) by BTS Company in connection with the performance of the Services.

     The terms of this Agreement will not prohibit BTS Company from marketing
the BTS Sites to third parties.

             V. OWNERSHIP OF WORK PRODUCT AND INTELLECTUAL PROPERTY

     5.1 OWNERSHIP OF WORK PRODUCT. To the extent that Carrier pays BTS Company
for any of the written work product generated in the course of performing the
Services (the "WORK PRODUCT"), BTS Company hereby assigns to Carrier all of BTS
Company's right title and interest in the Work Product, including without
limitation all engineering or architectural drawings and specifications
developed by BTS Company in connection with the Site Acquisition Services and
all intellectual property rights embodied therein.

     Except as provided elsewhere in this Agreement, no rights or licenses to
the Work Product or Carrier's Confidential Information or to trademarks,
inventions, copyrights, or patents embodied therein are implied or granted under
this Agreement.

     5.2 OWNER'S RIGHT TO COMPLETE WORK. If BTS Company defaults or neglects to
carry out any of its obligations, or takes any action, or omits to do anything
which endangers safety, or risks damage or injury to persons or property and
fails to remedy the default within the applicable cure period, Carrier may
correct all such work, omissions, or deficiencies, and Carrier shall be entitled
to recover its reasonable costs and expenses, including reasonable attorneys'
fees, pertaining thereto from BTS Company. This remedy provided for in this
SECTION 5.2 shall be in addition to, and not in lieu of any other right or
remedy which may be afforded to Carrier herein or under applicable law.

                                VI. MISCELLANEOUS

     6.1 PERMITS. BTS Company shall (without additional compensation) keep
current all governmental permits, certificates, and licenses (including
professional licenses) required by law to be in BTS Company's name necessary to
perform the services hereunder.

     6.2 PUBLICITY. Neither party shall make news releases or issue other
advertising pertaining to the Services or this Agreement without prior written
approval of the other party; provided however, that both parties agree to either
approve or deny such news release or advertising within five (5) business days
of the request for approval from the other party. In the event a party fails to
either approve or deny such news release or advertisement within five (5)
business days, such news release or advertisement shall be deemed approved.

                                       14
<PAGE>   15

     6.3 NOTICES. All notices, approvals, consents or other communications
hereunder shall be in writing and shall be deemed to have been duly delivered
and effective upon receipt if personally delivered, or on receipt if mailed by
prepaid overnight express service, addressed to the following (or other
addresses as the parties hereto may designate):

<TABLE>
<S>                                          <C>
         If to Carrier, to:                  If to BTS Company, to:

         Texas Telecommunications, LP        SBA Towers,
         Alamosa Wisconsin Limited
         Partnership
         4403 Brownfield Hwy                 One Town Center Road, 3rd Floor
         Lubbock, Texas  79407               Boca Raton, FL 33486
                                             Attn: General Counsel
         With a copy to:
         Steven A. Portonoy, Esq.
         Attorney at Law
         14800 Quorum Drive
         Suite 200
         Dallas, Texas  75240
</TABLE>

     6.4 BINDING EFFECT. The Agreement shall be binding upon and enforceable by,
and inure to the benefit of, successors, assigns, and transferees of the
parties.

     6.5 FURTHER ASSURANCES. The parties shall execute and deliver such further
instruments and perform such further acts as may reasonably be required to carry
out the intent and purposes of this Agreement.

     6.6 CHOICE OF LAW; JURISDICTION AND VENUE. The Agreement shall be governed
by and construed in accordance with the laws of the state where the applicable
Site or Search Ring are located. If the issue in dispute does not relate to a
specific Site or Search Ring, the Agreement shall be governed by and construed
in accordance with the laws of the State of Texas, excluding the conflict of law
provisions thereof. Each of the parties acknowledge that a substantial portion
of negotiations and execution of this Agreement occurred or shall occur in
Dallas, Texas, and that, therefore, without limiting the jurisdiction or venue
of any other federal or state courts, each of the parties irrevocable and
unconditionally: (a) agrees that any suit, action or legal proceeding arising
out of or relating to this Agreement shall be brought in the courts of record of
the State of Texas, Dallas or the District Court of the United States in the
Dallas area; (b) consents to the jurisdiction of each such court in any such
suit, (c.) waives any objection which it may have to the laying of venue of any
such suit, action or proceeding in any of such courts; and (d) agrees that
service of any court paper may be effected on such party by mail, as provided in
this Agreement, or in such other manner as may be provided under applicable laws
or court rules in said State.

     6.7 WAIVER. The failure of either party to insist upon strict performance
of any obligation hereunder, irrespective of the length of time for which such
failure continue, shall not be a waiver of such party's right to demand strict
compliance in the future. No consent or waiver, express or implied, to or of any
breach or default in the performance of any obligation hereunder shall
constitute a consent or waiver to or of any other breach or default in the
performance of the same or any other obligation hereunder.

                                       15
<PAGE>   16

     6.8 SEVERABILITY. In case any term of this Agreement shall be held invalid,
illegal, or unenforceable in whole or in part, neither the validity of the
remaining part of such term nor the validity of the remaining terms of this
Agreement shall in any way be affected thereby.

     6.9 HEADINGS. All section and paragraph titles or captions contained in
this Agreement are for convenience only and shall not be deemed part of the text
of this Agreement.

     6.10 PRONOUNS. All pronouns and any variations thereof shall be deemed to
refer to the masculine, feminine, neuter, singular, or plural as the context may
require.

     6.11 COUNTERPARTS. This Agreement may be signed in any number of
counterparts, each of which shall be considered an original and all of which
taken together shall constitute one and the same instrument.

     6.12 MODIFICATION; AMENDMENT; ADDITIONAL SERVICES. This Agreement may be
amended only by a written instrument executed by an officer or authorized
representative of each of the parties. In the event that the parties, at any
time, desire BTS Company to provide services other than the types of those
provided for in this Agreement, then, at such time, the parties shall execute an
amendment to SECTION III of this Agreement, describing such services and the
payment to be made therefor in a manner substantially similar to the manner in
which services and payment for services are presently described therein. In the
event that the parties so amend this Agreement, this Agreement, as amended,
shall continue in full force and effect thereafter.

     6.13 CONSTRUCTION OF AGREEMENT. This Agreement shall be interpreted
according to its plain meaning and shall not be strictly construed against
either party.

     6.14 EFFECT OF AMENDMENT AND RESTATEMENT OF THE EXISTING MASTER DESIGN
BUILD AGREEMENT. On the date of this Agreement, the Existing Master Design Build
Agreement shall be amended, restated and superseded in its entirety. The parties
hereto acknowledge and agree that this Agreement does not constitute a
termination of any of the obligations under the Existing Master Design Build
Agreement and such obligations are in all respects continuing, as amended and
restated hereby. All references in the MSA to the "BTS Agreement" shall be
deemed references to this Agreement, and to the extent necessary to effect the
foregoing, the MSA is hereby deemed amended accordingly. This Agreement and the
MSA contain the entire understanding between and among the parties and supersede
any prior understandings and agreements among them respecting the subject matter
of this Agreement.

     6.15 NO BROKERS; INDEMNIFICATION FROM BROKER'S FEES. Carrier and BTS
Company hereby represent, agree and acknowledge that no broker or other person
is entitled to claim or to be paid a commission as a result of the execution and
delivery of the Existing Master Design Build Agreement or this Agreement. Each
of the parties shall indemnify, defend and hold the other party harmless for all
claims, damages, liabilities and expenses (including attorney's fees) arising
from a misrepresentation arising from the first sentence of this paragraph.

     6.16 EXHIBITS AND SCHEDULES. Each and every exhibit and schedule referred
to or otherwise mentioned in this Agreement is attached to this Agreement and is
and shall be construed to be made a part of this Agreement by such reference or
other mention at each point at which such reference or other mention occurs, in
the same manner and with the same effect as if each annex and exhibit were set
forth in full and at length every time it is referred to or otherwise mentioned.

                                       16
<PAGE>   17

     6.17 TIME IS OF THE ESSENCE. Time is of the essence of this Agreement.
Anywhere a day Certain is stated for payment or performance of any obligation,
the day certain so stated enters into and becomes a part of the consideration
for this Agreement. The parties recognize and agree that the time limits and
time periods provided herein are of the essence of this Agreement.

     6.18 DISPUTE RESOLUTION. In the event of a dispute under this Agreement
between the parties, each of the parties will appoint a designated employee to
meet to endeavor to resolve such dispute. The designated representatives will
use reasonable efforts to resolve the dispute within thirty (30) days from the
date that both parties have notified the other party of the name, phone number
and address of the designated employee. The designated representatives shall
meet as often as necessary during the thirty (30) day period to gather and
furnish to the other all information with respect to the matter in issue that is
appropriate for its resolution. If the dispute cannot be resolved by the
designated representatives within the thirty (30) day period, the parties may
then initiate formal proceedings. The parties agree that they will not initiate
formal proceedings until the expiration of the thirty (30) day period, unless
the statute of limitations governing any cause of action relating to the dispute
would expire prior to the expiration of the thirty (30) day period.

     6.19 REASONABLENESS. Notwithstanding anything to the contrary contained in
this Agreement, wherever consent or approval is required by a party hereto, such
consent or approval shall not be unreasonably withheld, conditioned or delayed,
except as otherwise specifically noted herein.

     6.20 LIEN WAIVER. Notwithstanding anything to the contrary contained in
this Agreement, BTS Company does hereby waive any security interest or lien,
inclusive of any landlord's lien, whether arising under contract, common law,
statute or otherwise, in and to Carrier's Equipment. BTS Company further
recognizes and acknowledges that Carrier has entered into certain financial
arrangements with Nortel Networks, Inc. as administrative agent for itself and
various other lenders ("LENDERS") and in connection therewith, Nortel Networks,
Inc. and the Lenders shall take a security interest in Carrier's Equipment and
the products and proceeds thereof. BTS Company further represents that such
waiver and representations noted herein shall inure to the benefit of Carrier,
Nortel Networks, Inc., the Lenders and their successors and assigns.

                                       17
<PAGE>   18

     IN WITNESS WHEREOF, BTS Company and Carrier have duly executed and
delivered this Agreement. The party last executing this Agreement shall insert
the date of such execution on the first page hereof, which date shall be the
effective date of this Agreement.

                                      BTS COMPANY:

                                      SBA TOWERS, INC.

                                      By: /s/ JEFFREY LANGDON
                                          --------------------------------------
                                          Name: Jeffrey Langdon
                                          Title: V.P., Sales and Marketing

                                      CARRIER:
                                      TEXAS TELECOMMUNICATIONS, L.P.,
                                      a Texas limited partnership

                                      By: Alamosa Delaware GP, LLC, its general
                                          partner

                                      By: /s/ DAVID SHARBUTT
                                          --------------------------------------
                                          Name: David Sharbutt
                                          Title: Chief Executive Officer

                                      ALAMOSA WISCONSIN LIMITED PARTNERSHIP

                                      BY: ALAMOSA WISCONSIN GP, LLC, ITS
                                          GENERAL PARTNER

                                      By: /s/ DAVID SHARBUTT
                                          --------------------------------------
                                          Name: David Sharbutt
                                          Title: Chief Executive Officer

                                       18<PAGE>   1
                                                                    EXHIBIT 10.7

                                   [UPR LOGO]

                                      1995

                      STOCK OPTION AND RETENTION STOCK PLAN

                                       OF

                       UNION PACIFIC RESOURCES GROUP INC.

                             AS AMENDED AND RESTATED
                          (EFFECTIVE DECEMBER 7, 1999)

<PAGE>   2

                   1995 STOCK OPTION AND RETENTION STOCK PLAN
                      OF UNION PACIFIC RESOURCES GROUP INC.
              (AS AMENDED AND RESTATED EFFECTIVE DECEMBER 7, 1999)

--------------------------------------------------------------------------------
                                   1. PURPOSE

This 1995 Stock Option and Retention Stock Plan of Union Pacific Resources Group
Inc. is to promote and closely align the interests of officers and employees
with those of the shareholders of Union Pacific Resources Group Inc. by
providing stock based compensation. The Plan is intended to strengthen Union
Pacific Resources Group Inc.'s ability to reward performance which enhances long
term shareholder value; to increase employee stock ownership through performance
based compensation plans; and to strengthen the company's ability to attract and
retain an outstanding employee and executive team.

--------------------------------------------------------------------------------
                                 2. DEFINITIONS

The following terms shall have the following meanings:

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

         "Approved Leave of Absence" means a leave of absence of definite length
approved by the Vice President - People of the Company, or by any other officer
of the Company to whom the Committee delegates such authority.

         "Award" means an award of Retention Shares pursuant to the Plan.

         "Beneficiary" means any person or persons designated in writing by a
Participant to the Committee on a form prescribed by it for that purpose, which
designation shall be revocable at any time by the Participant prior to his or
her death, provided that, in the absence of such a designation or the failure of
the person or persons so designated to survive the Participant, "Beneficiary"
shall mean such Participant's estate; and further provided that no designation
of Beneficiary shall be effective unless it is received by the Company before
the Participant's death.

         "Board" means the Board of Directors of the Company.

         "Code" means the Internal Revenue Code of 1986, as amended, or the
corresponding provisions of any successor statute.

         "Committee" means the Committee designated by the Board to administer
the Plan pursuant to Section 3.

                                      -2-
<PAGE>   3

         "Common Stock" means the Common Stock of the Company.

         "Company" means Union Pacific Resources Group Inc., a Utah corporation,
or any successor corporation.

         "Option" means each non-qualified stock option, incentive stock option
and stock appreciation right granted under the Plan, including a Rollover
Option.

         "Optionee" means the Chairman of the Board or any employee of the
Company or a Subsidiary (including directors who are also such employees) who is
granted an Option under the Plan.

         "Participant" means the Chairman of the Board or any employee of the
Company or a Subsidiary (including directors who are also such employees) who is
granted an Award under the Plan.

         "Plan" means this 1995 Stock Option and Retention Stock Plan of Union
Pacific Resources Group Inc., as amended from time to time.

         "Retention Shares" means shares of Common Stock subject to an Award
granted under the Plan, including Rollover Retention Shares.

         "Restriction Period" means the period defined in Section 9(a).

         "Rollover Option" means an Option granted under the Plan in exchange
for UPC Stock Options.

         "Rollover Retention Shares" means shares of Common Stock subject to an
Award granted under the Plan in exchange for UPC Retention Shares.

         "Subsidiary" means any corporation, partnership, or limited liability
company of which the Company owns directly or indirectly at least a majority of
the outstanding shares of voting stock or other voting interest.

         "UPC" means Union Pacific Corporation, a Utah corporation.

         "UPC Plans" mean the 1993 Stock Option and Retention Stock Plan of
Union Pacific Corporation, the 1990 Retention Stock Plan of Union Pacific
Corporation, the 1988 Stock Option and Restricted Stock Plan of Union Pacific
Corporation and the 1982 Stock Option and Restricted Stock Plan of Union Pacific
Corporation.

         "UPC Stock Option" means any option granted under any UPC Plan.

         "UPC Retention Shares" means shares of common stock of UPC granted and
subject to restrictions under the UPC Plans.

                                      -3-
<PAGE>   4

         "Vesting Condition" means any condition to the vesting of Retention
Shares established by the Committee pursuant to Section 9.

--------------------------------------------------------------------------------
                                3. ADMINISTRATION

The Plan shall be administered by the Committee which shall comprise not less
than three persons, who shall be members of the Board, none of whom shall be
employees of the Company or any Subsidiary. Any actions taken with respect to a
"covered employee" within the meaning of Code section 162(m) shall be taken by
two or more "outside directors" as required by Code section 162(m). The
Committee shall (i) grant Options to Optionees and make Awards of Retention
Shares to Participants, and (ii) determine the terms and conditions of such
Options and Awards of Retention Shares, all in accordance with the provisions of
the Plan. The Committee shall have full authority to construe and interpret the
Plan, to establish, amend and rescind rules and regulations relating to the
Plan, to administer the Plan, and to take all such steps and make all such
determinations in connection with the Plan and Options and Awards granted
thereunder as it may deem necessary or advisable. The Committee may delegate its
authority under the Plan to one or more officers or employees of the Company or
a Subsidiary, provided, however, that no delegation shall be made of authority
to take an action which is required by Rule 16b-3 promulgated under the Act to
be taken by "non-employee directors" in order that the Plan and transactions
thereunder meet the requirements of such Rule. Each Option and grant of
Retention Shares shall, if required by the Committee, be evidenced by an
agreement to be executed by the Company and the Optionee or Participant,
respectively, and contain provisions not inconsistent with the Plan. All
determinations of the Committee shall be by a majority of its members and shall
be evidenced by resolution, written consent or other appropriate action, and the
Committee's determinations shall be final. Each member of the Committee, while
serving as such, shall be considered to be acting in his or her capacity as a
director of the Company.

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                                 4. ELIGIBILITY

To be eligible for selection by the Committee to participate in the Plan an
individual must be an employee of the Company or a Subsidiary, provided, that
the Chairman of the Board shall be eligible to receive Rollover Options.
Directors other than the Chairman of the Board who are not full-time salaried
employees shall not be eligible. In granting Options or Awards of Retention
Shares to eligible persons, the Committee shall take into account their duties,
their present and potential contributions to the success of the Company or a
Subsidiary, and such other factors as the Committee shall deem relevant in
connection with accomplishing the purpose of the Plan.

                                      -4-
<PAGE>   5

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                          5. STOCK SUBJECT TO THE PLAN

Subject to the provisions of Section 11 hereof, the maximum number and kind of
shares as to which Options or Retention Shares may at any time be granted under
the Plan are 23 million shares of Common Stock. No Participant may receive
Options (excluding Rollover Options) or Awards (excluding Rollover Retention
Shares) aggregating more than 25% of the shares of Common Stock available under
the Plan. Shares of Common Stock subject to Options or Awards under the Plan may
be either authorized but unissued shares or shares previously issued and
reacquired by the Company. Upon the expiration, termination or cancellation (in
whole or in part) of unexercised Options, shares of Common Stock subject thereto
shall again be available for option or grant as Retention Shares under the Plan.
Shares of Common Stock covered by an Option, or portion thereof, which is
surrendered upon the exercise of a stock appreciation right, shall thereafter be
unavailable for option or grant as Retention Shares under the Plan. Upon the
forfeiture (in whole or in part) of a grant of Retention Shares, the shares of
Common Stock subject to such forfeiture shall again be available for option or
grant as Retention Shares under the Plan if no dividends have been paid on the
forfeited shares, and otherwise shall be unavailable for such an option or
grant.

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                6. TERMS AND CONDITIONS OF NON-QUALIFIED OPTIONS

All non-qualified options under the Plan shall be granted subject to the
following terms and conditions:

         (a) OPTION PRICE. The option price per share with respect to each
option, other than Rollover Options, shall be determined by the Committee but
shall not be less than 100% of the fair market value of the Common Stock on the
date the option is granted, such fair market value to be determined in
accordance with the procedures to be established by the Committee. Rollover
Options shall each have an option price per share determined by the Committee,
provided that, unless the Committee determines otherwise in a specific case, the
aggregate gain or loss, as determined by the Committee, implicit in the Rollover
Options granted to each Optionee shall be equal to the aggregate gain or loss
implicit in the UPC Stock Options surrendered in exchange for such Rollover
Options.

         (b) DURATION OF OPTIONS. Options shall be exercisable at such time or
times and under such conditions as set forth in the written agreement evidencing
such option, but in no event shall any option be exercisable subsequent to the
tenth anniversary of the date on which the option is granted or, in the case of
Rollover Options, of the date of grant of the UPC Stock Option for which such
Rollover Option was exchanged.

         (c) EXERCISE OF OPTION. Except as provided in Section 6(h), 6(i) or
8(c), the shares of Common Stock covered by an option may not be purchased prior
to the first anniversary of the date on which the option is granted or, in the
case of Rollover Options, prior to the date of exercise of the UPC Stock Option
for which such Rollover Option was exchanged (unless the Committee shall
determine otherwise), or such longer period or periods, and subject to such
conditions, as the Committee may determine, but thereafter may be purchased at
one time or in such installments over the balance of the option period as may be
provided in the option,

                                      -5-
<PAGE>   6

provided, however, that no option (other than Rollover Options) shall be
exercisable before the earlier of (i) December 31, 1997, or (ii) one year after
UPC no longer owns at least 50% of the voting power of all shares of the Company
entitled to vote generally in the election of directors. Any shares not
purchased on the applicable installment date may, unless the Committee shall
have determined otherwise, be purchased thereafter at any time prior to the
final expiration of the option. To the extent that the right to purchase shares
has accrued thereunder, options may be exercised from time to time by written
notice to the Company stating the number of shares with respect to which the
option is being exercised.

         (d) PAYMENT. Shares of Common Stock purchased under options shall, at
the time of purchase, be paid for in full, unless the Committee shall otherwise
determine. All, or any portion, of the option exercise price may, at the
discretion of the Committee, be paid by the surrender to the Company, at the
time of exercise, of shares of previously acquired Common Stock owned by the
Optionee, to the extent that such payment does not require the surrender of a
fractional share of such previously acquired Common Stock. Such previously
acquired shares shall be valued at fair market value on the date the option is
exercised in accordance with the procedures to be established by the Committee.
A holder of an option shall have none of the rights of a stockholder. If an
amount is payable by an Optionee to the Company or a Subsidiary under applicable
withholding tax laws in connection with the exercise of non-qualified options,
the Committee may, in its discretion and subject to such rules as it may adopt,
permit the Optionee to make such payment, in whole or in part, by electing to
authorize the Company to withhold or accept shares of Common Stock having a fair
market value not exceeding the minimum applicable amount to be paid under such
withholding tax laws (based on the minimum applicable statutory withholding
rates for federal and state tax purposes, including payroll taxes).

         (e) RESTRICTIONS. The Committee shall determine, with respect to each
option, the nature and extent of the restrictions, if any, to be imposed on the
shares of Common Stock which may be purchased thereunder including restrictions
on the transferability of such shares acquired through the exercise of such
option. Without limiting the generality of the foregoing, the Committee may
impose conditions restricting absolutely or conditionally the transferability of
shares acquired through the exercise of options for such periods, and subject to
such conditions, including continued employment of the Optionee by the Company
or a Subsidiary, as the Committee may determine.

         (f) PURCHASE FOR INVESTMENT. The Committee shall have the right to
require that each Optionee or other person who shall exercise an option under
the Plan represent and agree that any shares of Common Stock purchased pursuant
to such option will be purchased for investment and not with a view to the
distribution or resale thereof or that such shares will not be sold except in
accordance with such restrictions or limitations as may be set forth in the
written agreement granting such option.

         (g) NON-TRANSFERABILITY OF OPTIONS. During an Optionee's lifetime, the
option may be exercised only by the Optionee. Options shall not be transferable,
except for exercise by the Optionee's legal representatives or heirs. An officer
of the Company may, with prior approval from the Committee (or its designee) as
to form, transfer an exercisable non-qualified Option or Rollover Option to (a)
a member or members of the officer's immediate family (spouse, children and
grandchildren, including step and adopted children and grandchildren), (b) a
trust, the

                                      -6-
<PAGE>   7

beneficiaries of which consist exclusively of members of the officer's immediate
family, (c) a partnership, the partners of which consist exclusively of members
of the officer's immediate family, or (d) any similar entity created for the
exclusive benefit of members of the officer's immediate family. The Committee or
its designee must approve the form of any transfer of a Grant to or for the
benefit of any immediate family member or members before such transfer shall be
recognized as valid hereunder. For purposes of the preceding sentence, any
remote, contingent interest of persons other than a member of the officer's
immediate family shall be disregarded. For purposes of this Section 6(g), the
term "officer" shall have the same meaning as that term is defined in Rule
16a-1(f) of the Act. A person's status as an officer shall be determined at the
time of the intended transfer.

         (h) TERMINATION OF EMPLOYMENT. Upon the termination of an Optionee's
employment, for any reason other than death, the option shall be exercisable
only as to those shares of Common Stock which were then subject to the exercise
of such option, provided that (I) in the case of disability as described below,
any holding period required by Section 6(c) shall automatically be deemed to be
satisfied and (II) the Committee may determine that particular limitations and
restrictions under the Plan shall not apply, and such option shall expire
according to the following schedule (unless the Committee shall otherwise
determine):

                  (i) RETIREMENT. Option shall expire, unless exercised, five
         (5) years after the Optionee's retirement from the Company or any
         Subsidiary under the provisions of the Company's or a Subsidiary's
         pension plan.

                  (ii) DISABILITY. Option shall expire, unless exercised, five
         (5) years after the date the Optionee is eligible to receive disability
         benefits under the provisions of the Company's or a Subsidiary's
         long-term disability plan.

                  (iii) GROSS MISCONDUCT. Option shall expire upon receipt by
         the Optionee of the notice of termination if he or she is terminated
         for deliberate, willful or gross misconduct as determined by the
         Company.

                  (iv) ALL OTHER TERMINATIONS. Option shall expire, unless
         exercised, three (3) months after the date of such termination.

         (i) DEATH OF OPTIONEE. Upon the death of an Optionee during his or her
period of employment, the option shall be exercisable only as to those shares of
Common Stock which were subject to the exercise of such option at the time of
his or her death, provided that (I) any holding period required by Section 6(c)
shall automatically be deemed to be satisfied and (II) the Committee may
determine that particular limitations and restrictions under the Plan shall not
apply, and such option shall expire, unless exercised by the Optionee's legal
representatives or heirs, five (5) years after the date of death (unless the
Committee shall provide for a shorter period at the time the option is granted).

                  In no event, however, shall any option be exercisable pursuant
to Sections 6(h) or (i) subsequent to the tenth anniversary of the date on which
it is granted or, in the case of a Rollover Option, of the date of grant of the
UPC Stock Option(s) for which such Rollover Option was exchanged.

                                      -7-
<PAGE>   8

         (j) ROLLOVER OPTIONS. Rollover Options may be granted only in exchange
for UPC Stock Options and only during the period prior to 90 days after UPC no
longer owns at least 50% of the voting power of all of the shares of the Company
entitled to vote generally in the election of directors. The ratio for such
exchange shall be determined by the Committee, provided that the requirements of
Section 6(a) are met.

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              7. TERMS AND CONDITIONS OF STOCK APPRECIATION RIGHTS

         (a) GENERAL. The Committee may also grant a stock appreciation right in
connection with a non-qualified option, either at the time of grant or by
amendment. Such stock appreciation right shall cover the same shares covered by
such option (or such lesser number of shares of Common Stock as the Committee
may determine) and shall, except for the provisions of Section 6(d) hereof, be
subject to the same terms and conditions as the related non-qualified option.

         (b) EXERCISE AND PAYMENT. Each stock appreciation right shall entitle
the Optionee to surrender to the Company unexercised the related option, or any
portion thereof, and to receive from the Company in exchange therefor an amount
equal to the excess of the fair market value of one share of Common Stock over
the option price per share times the number of shares covered by the option, or
portion thereof, which is surrendered. Payment shall be made in shares of Common
Stock valued at fair market value, or in cash, or partly in shares and partly in
cash, all as shall be determined by the Committee. The fair market value shall
be the value determined in accordance with procedures established by the
Committee. Stock appreciation rights may be exercised from time to time upon
actual receipt by the Company of written notice stating the number of shares of
Common Stock with respect to which the stock appreciation right is being
exercised, provided that if a stock appreciation right expires unexercised, it
shall be deemed exercised on the expiration date if any amount would be payable
with respect thereto. No fractional shares shall be issued but instead cash
shall be paid for a fraction or, if the Committee should so determine, the
number of shares shall be rounded downward to the next whole share. If an amount
is payable by an Optionee to the Company or a Subsidiary under applicable
withholding tax laws in connection with the exercise of stock appreciation
rights, the Committee may, in its discretion and subject to such rules as it may
adopt, permit the Optionee to make such payment, in whole or in part, by
electing to authorize the Company to withhold or accept shares of Common Stock
having a fair market value equal to the amount to be paid under such withholding
tax laws.

         (c) RESTRICTIONS. The obligation of the Company to satisfy any stock
appreciation right exercised by an Optionee subject to Section 16 of the Act
shall be conditioned upon the prior receipt by the Company of an opinion of
counsel to the Company that any such satisfaction will not create an obligation
on the part of such Optionee pursuant to Section 16(b) of the Act to reimburse
the Company for any statutory profit which might be held to result from such
satisfaction.

                                      -8-
<PAGE>   9

--------------------------------------------------------------------------------
               8. TERMS AND CONDITIONS OF INCENTIVE STOCK OPTIONS

         (a) GENERAL. The Committee may also grant incentive stock options as
defined under section 422 of the Code. All incentive stock options issued under
the Plan shall, except for the provisions of Sections 6(g) (to the extent it
allows the Committee to permit options to be transferred to, or for the benefit
of, the Optionee's immediate family members), 6(h) and (i) and Section 7 hereof,
be subject to the same terms and conditions as the non-qualified options granted
under the Plan, and may be Rollover Options subject to Section 6(j) hereof;
provided, however, that no incentive stock option which is a Rollover Option
shall confer additional benefits (within the meaning of section 424(h)(3) of the
Code) upon the Optionee which the Optionee did not have under the UPC Stock
Option surrendered in exchange therefor. In addition, incentive stock options
shall be subject to the conditions of Sections 8(b), (c), (d) and (e).

         (b) LIMITATION OF EXERCISE. The aggregate fair market value (determined
as of the date the incentive stock option is granted) of the shares of stock
with respect to which incentive stock options are exercisable for the first time
by such Optionee during any calendar year, under this Plan or any other stock
option plans adopted by the Company, its Subsidiaries or any predecessor
companies thereof, other than Rollover Options issued in exchange for UPC
Options which were exercisable by the Optionee at the time of exchange, shall
not exceed $100,000. If any incentive stock options become exercisable in any
year in excess of the $100,000 limitation, options representing such excess
shall become non-qualified options exercisable pursuant to the terms of Section
6 hereof and shall not be exercisable as incentive stock options.

                                      -9-
<PAGE>   10

         (c) TERMINATION OF EMPLOYMENT. Upon the termination of an Optionee's
employment, for any reason other than death, his or her incentive stock option
shall be exercisable only as to those shares of Common Stock which were then
subject to the exercise of such option provided that (I) in the case of
disability as described below, any holding period required by Section 6(c) shall
automatically be deemed to be satisfied and (II) the Committee may determine
that particular limitations and restrictions under the Plan shall not apply, and
such option shall expire as an incentive stock option (but shall become a
non-qualified option exercisable pursuant to the terms of Section 6 hereof less
the period already elapsed under such Section), according to the following
schedule (unless the Committee shall provide for shorter periods at the time the
incentive stock option is granted):

                  (i) RETIREMENT. An incentive stock option shall expire, unless
         exercised, three (3) months after the Optionee's retirement from the
         Company or any Subsidiary under the provisions of the Company's or a
         Subsidiary's pension plan.

                  (ii) DISABILITY. In the case of an Optionee who is disabled
         within the meaning of section 22(e)(3) of the Code, an incentive stock
         option shall expire, unless exercised, one (1) year after the earlier
         of the date the Optionee terminates employment or the date the Optionee
         is eligible to receive disability benefits under the provisions of the
         Company's or a Subsidiary's long-term disability plan.

                  (iii) GROSS MISCONDUCT. An incentive stock option shall expire
         upon receipt by the Optionee of the notice of termination if he or she
         is terminated for deliberate, willful or gross misconduct as determined
         by the Company.

                  (iv) ALL OTHER TERMINATIONS. An incentive stock option shall
         expire, unless exercised, three (3) months after the date of such
         termination.

         (d) DEATH OF OPTIONEE. Upon the death of an Optionee during his or her
period of employment, the incentive stock option shall be exercisable as an
incentive stock option only as to those shares of Common Stock which were
subject to the exercise of such option at the time of death, provided that (I)
any holding period required by Section 6(c) shall automatically be deemed to be
satisfied, and (II) the Committee may determine that particular limitations and
restrictions under the Plan shall not apply, and such option shall expire,
unless exercised by the Optionee's legal representatives or heirs, five (5)
years after the date of death (unless the Committee shall provide for a shorter
period at the time the option is granted).

         (e) LEAVE OF ABSENCE. A leave of absence, whether or not an Approved
Leave of Absence, shall be deemed a termination of employment for purposes of
Section 8.

                  In no event, however, shall any incentive stock option be
exercisable pursuant to Sections 8(c) or (d) subsequent to the tenth anniversary
of the date on which it was granted or, in the case of a Rollover Option, of the
date of grant of the UPC Stock Option(s) for which such Rollover Option was
exchanged.

                                      -10-
<PAGE>   11

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              9. TERMS AND CONDITIONS OF AWARDS OF RETENTION STOCK

         (a) GENERAL. Retention Shares (other than Rollover Retention Shares)
may be granted to reward the attainment of individual, Company or Subsidiary
goals, or to attract or retain officers or other employees of the Company or any
Subsidiary. With respect to each grant of Retention Shares under the Plan, the
Committee shall determine the period or periods, including any conditions for
determining such period or periods, during which the restrictions set forth in
Section 9(b) shall apply, provided that in no event, other than as provided in
Section 9(c) or unless the Committee shall determine otherwise, shall such
restrictions terminate prior to 1 year after the date of grant, except for
Rollover Retention Shares, in which case such restrictions shall not terminate
prior to 3 years after the date of grant of the UPC Retention Shares for which
such Rollover Retention Shares are exchanged (the "Restriction Period"), and may
also specify any other terms or conditions to the right of the Participant to
receive such Retention Shares ("Vesting Conditions"). Subject to Section 9(c)
and any such Vesting Condition, a grant of Retention Shares shall be effective
for the Restriction Period and may not be revoked.

         (b) RESTRICTIONS. At the time of grant of Retention Shares to a
Participant, a certificate representing the number of shares of Common Stock
granted shall be registered in the Participant's name but shall be held by the
Company for his or her account. The Participant shall have the entire beneficial
ownership interest in, and all rights and privileges of a stockholder as to,
such Retention Shares, including the right to vote such Retention Shares and,
unless the Committee shall determine otherwise, the right to receive dividends
thereon, subject to the following: (i) subject to Section 9(c), the Participant
shall not be entitled to delivery of the stock certificate until the expiration
of the Restriction Period and the satisfaction of any Vesting Conditions; (ii)
none of the Retention Shares may be sold, transferred, assigned, pledged, or
otherwise encumbered or disposed of during the Restriction Period or prior to
the satisfaction of any Vesting Conditions; and (iii) all of the Retention
Shares shall be forfeited and all rights of the Participant to such Retention
Shares shall terminate without further obligation on the part of the Company
unless the Participant remains in the continuous employment of the Company or a
Subsidiary for the entire Restriction Period, except as provided by Sections
9(a) and 9(c), and any applicable Vesting Conditions have been satisfied. Any
shares of Common Stock or other securities or property received as a result of a
transaction listed in Section 11 shall be subject to the same restrictions as
such Retention Shares unless the Committee shall determine otherwise.

                                      -11-
<PAGE>   12

         (c) TERMINATION OF EMPLOYMENT.

                  (i) DISABILITY AND RETIREMENT. Unless the Committee shall
         determine otherwise at the time of grant of Retention Shares, if (A) a
         Participant ceases to be an employee of the Company or a Subsidiary
         prior to the end of a Restriction Period, by reason of disability under
         the provisions of the Company's or a Subsidiary's long-term disability
         plan or retirement under the provisions of the Company's or a
         Subsidiary's pension plan either (i) at age 65 or (ii) prior to age 65
         at the request of the Company or a Subsidiary, and (B) all Vesting
         Conditions have been satisfied, the Retention Shares granted to such
         Participant shall immediately vest and all restrictions applicable to
         such shares shall lapse. A certificate for such shares shall be
         delivered to the Participant in accordance with the provisions of
         Section 9(d).

                  (ii) DEATH. Unless the Committee shall determine otherwise at
         the time of grant of Retention Shares, if (A) a Participant ceases to
         be an employee of the Company or a Subsidiary prior to the end of a
         Restriction Period by reason of death, and (B) all Vesting Conditions
         have been satisfied, the Retention Shares granted to such Participant
         shall immediately vest in his or her Beneficiary, and all restrictions
         applicable to such shares shall lapse. A certificate for such shares
         shall be delivered to the Participant's Beneficiary in accordance with
         the provisions of Section 9(d).

                  (iii) ALL OTHER TERMINATIONS. If a Participant ceases to be an
         employee of the Company or a Subsidiary prior to the end of a
         Restriction Period for any reason other than death, disability or
         retirement as provided in Section 9(c)(i) and (ii), the Participant
         shall immediately forfeit all Retention Shares then subject to the
         restrictions of Section 9(b) in accordance with the provisions thereof,
         except that the Committee may, if it finds that the circumstances in
         the particular case so warrant, allow a Participant whose employment
         has so terminated to retain any or all of the Retention Shares then
         subject to the restrictions of Section 9(b) and all restrictions
         applicable to such retained shares shall lapse. A certificate for such
         retained shares shall be delivered to the Participant in accordance
         with the provisions of Section 9(d).

                  (iv) VESTING CONDITIONS. Unless the Committee shall determine
         otherwise at the time of grant of Retention Shares, if a Participant
         ceases to be an employee of the Company or a Subsidiary for any reason
         prior to the satisfaction of any Vesting Conditions, the Participant
         shall immediately forfeit all Retention Shares then subject to the
         restrictions of Section 9(b) in accordance with the provisions thereof,
         except that the Committee may, if it finds that the circumstances in
         the particular case so warrant, allow a Participant whose employment
         has so terminated to retain any or all of the Retention Shares then
         subject to the restrictions of Section 9(b) and all restrictions
         applicable to such retained shares shall lapse. A certificate for such
         retained shares shall be delivered to the Participant in accordance
         with the provisions of Section 9(d).

         (d) PAYMENT OF RETENTION SHARES. At the end of the Restriction Period
and after all Vesting Conditions have been satisfied, or at such earlier time as
provided for in Section 9(c) or as the Committee, in its sole discretion, may
otherwise determine, all restrictions applicable to the Retention Shares shall
lapse, and a stock certificate for a number of shares of Common Stock

                                      -12-
<PAGE>   13

equal to the number of Retention Shares, free of all restrictions, shall be
delivered to the Participant or his or her Beneficiary, as the case may be. If
an amount is payable by a Participant to the Company or a Subsidiary under
applicable withholding tax laws in connection with the lapse of such
restrictions, the Committee, in its sole discretion, may permit the Participant
to make such payment, in whole or in part, by authorizing the Company

to transfer to the Company Retention Shares otherwise deliverable to the
Participant having a fair market value not exceeding the minimum applicable
amount to be paid under such withholding tax laws (based on the minimum
applicable statutory withholding rates for federal and state tax purposes,
including payroll taxes).

         (e) ROLLOVER RETENTION SHARES. Rollover Retention Shares may be granted
only in exchange for shares of UPC Retention Stock granted and subject to
restrictions under a UPC Plan and only during the period prior to 90 days after
UPC no longer owns at least 50% of the voting power of all of the shares of the
Company entitled to vote generally in the election of directors. Unless the
Committee shall determine otherwise in a specific case, the Rollover Retention
Shares shall, on the date of exchange, have the same value, as determined by the
Committee, as the shares of UPC surrendered in exchange for such Rollover
Retention Shares.

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                      10. REGULATORY APPROVALS AND LISTING

The Company shall not be required to issue to an Optionee, Participant or a
Beneficiary, as the case may be, any certificate for any shares of Common Stock
upon exercise of an option or for any Retention Shares granted under the Plan
prior to (i) the obtaining of any approval from any governmental agency which
the Company, in its sole discretion, shall determine to be necessary or
advisable, (ii) the admission of such shares to listing on any stock exchange on
which the Common Stock may then be listed, and (iii) the completion of any
registration or other qualification of such shares under any state or Federal
law or rulings or regulations of any governmental body which the Company, in its
sole discretion, shall determine to be necessary or advisable.
--------------------------------------------------------------------------------
              11. ADJUSTMENT IN EVENT OF CHANGES IN CAPITALIZATION

In the event of a recapitalization, stock split, stock dividend, combination or
exchange of shares, merger, consolidation, rights offering, separation,
spin-off, reorganization or liquidation, or any other change in the corporate
structure or shares of the Company, the Board, upon recommendation of the
Committee, may make such equitable adjustments as it may deem appropriate in the
number and kind of shares authorized by the Plan, in the option price of
outstanding Options, and in the number and kind of shares or other securities or
property subject to Options or covered by outstanding Awards.

                                      -13-
<PAGE>   14

--------------------------------------------------------------------------------
                              12. TERM OF THE PLAN

No Options or Retention Shares shall be granted pursuant to the Plan after
September 27, 2005 but grants of Options and Retention Shares theretofore
granted may extend beyond that date and the terms and conditions of the Plan
shall continue to apply thereto.

--------------------------------------------------------------------------------
                    13. TERMINATION OR AMENDMENT OF THE PLAN

The Board may at any time terminate the Plan with respect to any shares of
Common Stock not at that time subject to outstanding Options or Awards, and may
from time to time alter or amend the Plan or any part thereof (including, but
without limiting the generality of the foregoing, any amendment deemed necessary
to ensure that the Company may obtain any approval referred to in Section 10 or
to ensure that the grant of Options or Awards, the exercise of Options or
payment of Retention Shares or any other provision or the Plan complies with
Section 16(b) of the Act), provided that no change with respect to any Options
or Retention Shares theretofore granted may be made which would impair the
rights of an Optionee or Participant without the consent of such Optionee or
Participant and, further, that without the approval of stockholders, no
alteration or amendment may be made which would (i) increase the maximum number
of shares of Common Stock subject to the Plan as set forth in Section 5 (except
by operation of Section 11), (ii) extend the term of the Plan, (iii) change the
class of eligible persons who may receive Options or Awards of Retention Shares
under the Plan or (iv) increase the limitation set forth in Section 5 on the
maximum number of shares that any Participant may receive under the Plan.

--------------------------------------------------------------------------------
                              14. LEAVE OF ABSENCE

Unless the Committee shall determine otherwise, a leave of absence other than an
Approved Leave of Absence shall be deemed a termination of employment for
purposes of the Plan. An Approved Leave of Absence shall not be deemed a
termination of employment for purposes of the Plan (except for purposes of
Section 8), but the period of such Leave of Absence shall not be counted toward
satisfaction of any Restriction Period or any holding period described in
Section 6(c).

                                      -14-
<PAGE>   15

--------------------------------------------------------------------------------
                             15. GENERAL PROVISIONS

         (a) Neither the Plan nor the grant of any Option or Award nor any
action by the Company, any Subsidiary or the Committee shall be held or
construed to confer upon any person any right to be continued in the employ of
the Company or a Subsidiary. The Company and each Subsidiary expressly reserve
the right to discharge, without liability but subject to his or her rights under
the Plan, any Optionee or Participant whenever in the sole discretion of the
Company or a Subsidiary, as the case may be, its interest may so require.

         (b) All questions pertaining to the construction, regulation, validity
and effect of the Plan shall be determined in accordance with the laws of the
State of Utah, without regard to conflict of laws doctrine.

         (c) Notwithstanding any provision herein to the contrary, the
Committee, under terms and conditions as it may prescribe, may permit certain
Optionees (with respect to Non-Qualified Options and Stock Appreciation Rights)
and certain Participants (with respect to Awards of Retention Shares) to make
elections, engage in transactions or take any other action intended to defer the
receipt of compensation for federal income tax purposes with respect to such
Non-Qualified Options, Stock Appreciation Rights or Retention Shares. This
provision shall be effective on and after September 5, 1997.

         (d) With respect to any amendment to the Plan which becomes effective
on or after January 21, 1999, if the Company, at any time, desires to engage in
a transaction which is intended to be accounted for as a pooling of interests
under Accounting Principles Board Opinion No. 16 (or any successor thereto), and
if the existence and/or operation of any such amendment would violate Paragraph
47(c) thereof (or any successor thereto), then any such amendment shall (in
whole or in part to the minimum extent necessary to avoid a violation) be deemed
to have no force or effect under law; provided, however, that this subsection
(d) shall apply only if the transaction is otherwise eligible to be accounted
for as a pooling of interests.

                                      -15-

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