
<PAGE>

                                    SH98298

Exhibit 10.45
-------------

                                ADDENDUM VI
                                     TO
                      SPRINT PCS MANAGEMENT AGREEMENT

                         Dated as of March 30, 2001


Manager: ALAMOSA WISCONSIN LIMITED PARTNERSHIP

Service Area BTAs:

Appleton-Oshkosh # 18,
Eau Claire # 123,
Fond du Lac # 148,
Green Bay # 173,
La Crosse-Winona # 234,
Madison # 272 (Only Columbia, Juneau, Marquette, Sauk Counties and those
portions of Dane County where Manager will meet Sprint PCS coverage along
Highway 151 and I- 90/94 north of Madison),
Manitowoc # 276,
Milwaukee #297 (Only those portions of Dodge County not currently covered by
SprintPCS along Highway 41 and the City of Watertown),
Minneapolis-St. Paul # 298 (Only Barron County and those portions of Polk
County not currently covered by Sprint PCS along Highway 8 near the city of
St. Croix Falls),
Sheboygan # 417,
Stevens Point-Marshfield-Wisconsin Rapids # 432,
Wausau-Rhinelander # 466.


         This Addendum VI (this "Addendum") contains certain additional and
supplemental terms and provisions of that certain Sprint PCS Management
Agreement entered into as of December 6, 1999 by the same parties as this
Addendum, which Management Agreement was further amended by that certain
Addendum I entered into as of December 6, 1999, that certain Addendum II
entered into as of February 3, 2000, that certain Addendum III entered into
as of April 25, 2000, that certain Addendum IV entered into as of June 23,
2000, and that certain Addendum V entered into as of February 14, 2001 (the
"Management Agreement").

         The terms and provisions of the Addendum control, supersede and
amend any conflicting terms and provisions contained in the Management
Agreement. Except for express modifications made in this Addendum, the
Management Agreement and all prior addenda continue in full force and
effect.

         Capitalized terms used and not otherwise defined in this Addendum
have the meaning ascribed to them in the Schedule of Definitions. Section
and Exhibit references are to Sections and Exhibits of the Management
Agreement unless otherwise noted.

         The Management Agreement is modified as follows:

1. Use of Loan Proceeds. Sprint PCS is entering into that certain Amended
and Restated Consent and Agreement with Citicorp USA, Inc., dated as of
March 30, 2001 ("Citicorp") (which Amended and Restated Consent and
Agreement, as amended and modified from time to time, is referred to as the
"Consent and Agreement") to enable Manager to obtain a loan (the "Loan")
from Citicorp, its successors, and other lenders who from time to time are
parties to the Consent and Agreement (collectively, the "Lenders"). Manager
agrees that notwithstanding the permitted uses of the proceeds of the Loan,
it will not use the proceeds from the Loan or any other loan, extension of
credit or other obligation to which the Consent and Agreement relates, for
any purpose other than to (a) construct and operate the Service Area
Network within the Service Area (as may be amended from time to time) as
contemplated under the Management Agreement, (b) pay the cash portion of
the merger consideration to the Target (as defined in that certain
Commitment Letter dated March 9, 2001, between Citicorp North America,
Inc., Salomon Smith Barney, Inc., TD Securities (USA) Inc., Export
Development Corporation and Alamosa Holdings, Inc. (the "Commitment
Letter")), (c) refinance existing indebtedness under the Southwest Facility
(as that term is defined in the Commitment Letter), and (d) pay the
Transaction Costs (as that term is defined in the Commitment Letter).

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2. Definition of "Other Parties". The parties agree to amend the definition
of "Other Parties" to include Southwest PCS, L.P., an Oklahoma limited
partnership.

3. Revised Financing Plan. Exhibit 1.7 attached to this Addendum supersedes
and replaces in it entirety Exhibit 1.7 attached to the Management
Agreement.

4. Reaffirmation of Sprint Agreements. Each of the undersigned reaffirms in
their entirety, together with the respective rights and obligations
thereunder, the Management Agreement, the Services Agreement and the
License Agreements.

5. Counterparts. This Addendum may be executed in two or more counterparts,
each of which shall constitute an original but all which when taken
together shall constitute but one agreement.

         [the remainder of this page is intentionally left blank]



         IN WITNESS WHEREOF, the parties have caused this Addendum VI to be
executed as of the date first above written.

                              SPRINT SPECTRUM L.P.


                              By:  /s/  Thomas E. Mateer
                                   ------------------------------
                                    Thomas E. Mateer
                                    Vice President - Affiliations


                              WIRELESSCO, L.P.


                              By:  /s/  Thomas E. Mateer
                                   ------------------------------
                                    Thomas E. Mateer
                                    Vice President - Affiliations


                              SPRINT COMMUNICATIONS
                              COMPANY, L.P.


                              By:  /s/  Ed Mattix
                                   ------------------------------
                                    Ed Mattix,
                                    Senior Vice President - Public Affairs


                              ALAMOSA WISCONSIN LIMITED  PARTNERSHIP
                              a Wisconsin limited partnership


                              By:      ALAMOSA WISCONSIN GP, L.L.C.
                                       a Delaware limited liability company,
                                       as the sole general partner


                                       By:  /s/  David E. Sharbutt
                                            ------------------------------------
                                            David E. Sharbutt,
                                            President

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