<PAGE>
                                                                   Exhibit 10.18

                               SECOND AMENDMENT TO
                            MASTER SERVICES AGREEMENT

Confidential Treatment. The portions of this exhibit that have been replaced
with "[*****]" have been filed separately with the Securities and Exchange
Commission and are the subject of an application for confidential treatment.

         This Second Amendment ("Second Amendment") is effective as of the first
day of April, 2000 ("Second Amendment Effective Date") and amends and
supplements that certain Master Services Agreement, as amended (the "Agreement")
dated as of the 9th day of December, 1999, by and between VALOR
TELECOMMUNICATIONS ENTERPRISES, LLC (as successor to Valor Telecommunications
Southwest, LLC, successor to dba Communications, LLC) ("Client") and ALLTEL
INFORMATION SERVICES, INC. ("ALLTEL").

                                   WITNESSETH:

         WHEREAS, Client desires to obtain additional services from ALLTEL and
ALLTEL is willing to provide such services pursuant to the terms and conditions
contained herein;

         NOW, THEREFORE, in consideration of the mutual promises and covenants
herein, the parties agree as follows:

1.       The following new Section 2.5 shall be added to Exhibit E to the
         Agreement:

         "2.5     HARDWARE, SOFTWARE AND SUPPORT FOR SWITCH INTERFACE SOFTWARE.
                  ALLTEL shall acquire the following hardware, operating system
                  software, and support required for switch interface software
                  (such as Architel's switching activation software) on Client's
                  behalf: N9000 2cpu/3GB memory with local failover support and
                  miscellaneous software; 40 GB of storage; UNIX support; backup
                  services; maintenance (including software maintenance); and
                  related Oracle software licenses. Commencing April 1, 2000,
                  Client shall pay the following monthly Service Fees for such
                  hardware, software and support:

<TABLE>
<CAPTION>
                                                             MONTHLY FEES*
                                                             -------------
<S>                                                          <C>
April 1, 2000 through March 31, 2003                           $[*****]
April 1, 2003 and thereafter**                                 $[*****]***
</TABLE>

         *        The monthly fees set forth in this Section are based on the
                  assumption there will be no more than 550,000 Access Lines and
                  no more than 90 switches. If that assumption is materially
                  incorrect, ALLTEL and Client shall negotiate in good faith an
                  equitable adjustment to such fees.

         **       Client may cancel these Services, without penalty or
                  additional fees, at any time after April 1, 2003 by thirty
                  (30) Days' written notice to ALLTEL.

         ***      The monthly fees after March 31, 2003 are based on the
                  assumption that the same hardware and software can be used,
                  without upgrade. If that assumption is incorrect, ALLTEL and
                  Client shall negotiate in good faith an equitable adjustment
                  to such fees.

         The monthly fees set forth above include "Disaster Recovery Services",
         as provided for in Exhibit K.

                                        1
<PAGE>

2.       The following new Section 4 shall be added to Exhibit A to the
         Agreement:

         "4.      TIME MANAGEMENT SYSTEM. ALLTEL shall implement and support (in
                  the form of regular software upgrades and patches) ALLTEL's
                  Time Management System Software ("Time Management System")
                  which shall be used to track time for Client employees. ALLTEL
                  will provide one (1) interface from WFM to the Time Management
                  System. Valor shall have one (1) location, corporate
                  headquarters for the Time Management System. Time Management
                  System located at corporate headquarters will have an
                  automated interface to Pro-Business. The Time Management
                  System functionality described below will be implemented by
                  July 1, 2000, except for Short Term Disability and FMLA
                  Tracking and Reporting enhancements which are scheduled for
                  completion on August 1, 2000. ALLTEL will provide on-site
                  support for the Time Management System for a period of one (1)
                  week following the initial installation.

         "4.1     FUNCTIONALITY. THE FUNCTIONALITY PROVIDED BY THE CORE TIME
                  MANAGEMENT SYSTEM SOFTWARE IS:

                  -        LAN or PC based software;

                  -        Multi-user software;

                  -        32 bit processing software;

                  -        Manual input;

                  -        Mechanized input;

                  -        Mechanized input error correction;

                  -        Feed to Payroll system;

                  -        Validation of input date through maintenance tables;

                  -        Manual updates of maintenance tables;

                  -        Site specific table;

                  -        Inquiry function;

                  -        Daily time summary report;

                  -        Query report;

                  -        Weekly status report;

                  -        Mechanized input error report;

                  -        Reports saved as HTML for web reporting;

                  -        Utilities to re-index tables;

                  -        Utilities to pack tables;

                  -        Utilities to purge data from tables;

                  -        Utilities to release data;

                  -        Utilities to re-release data;

                  -        Utilities to set security levels;

                  -        Utilities to set user and user's security levels;

                  -        Utilities for online help; and

                  -        Utilities to update the online help.

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<PAGE>

         4.2      ENHANCEMENTS. Additionally, ALLTEL will provide Client with
                  the following enhancements to the core Time Management System
                  software, including:

                  -        Customized WFM import to match Client format;

                  -        Customized timesheet screen to match Client format;

                  -        Customized export to Pro-Business;

                  -        Work order validation;

                  -        Union order validation;

                  -        Union validation;

                  -        Exception Job Class Code rate logic;

                  -        Sick pay processing; and

                  -        Short Term Disability and FMLA Tracking and
                           Reporting.

                  ALLTEL will provide Client spreadsheet import capability
                  through Change Control. Spreadsheet import capability is not
                  within the scope of the 706 man-hours as set forth in 4.3
                  below.

         4.3      CUSTOMIZATION. ALLTEL will provide up to 706 man-hours of
                  development services to configure the Time Management System
                  for Client's use. The 706 man-hours of software development
                  services will provide the following types of customization:

                  -        Customization of report headings, menus and forms;

                  -        Definition of internal tables; and

                  -        Testing of the interface between the WFM and Payroll
                           system.

                  Customization exceeding the 706 man-hours (including new
                  reports, etc.) will be provided upon Client's written request
                  through the SER process for the Service Fees set forth in
                  Exhibit E.

         4.4      CLIENT RESPONSIBILITIES. Client is responsible for providing
                  Client employees and contractors with the appropriate desktop
                  PCs needed to access and utilize the Time Management System.
                  ALLTEL will assist Client's LAN Administrator with loading of
                  the Time Management System icon and loading of the directories
                  onto Client's LAN. ALLTEL will also assist with initial
                  operator setup. Client is responsible for the nightly backup
                  on the LAN to include the Time Management System data."

3.       The following new Section 2.4 shall be added to Exhibit E to the
         Agreement.

         "2.4     SERVICE FEES FOR TIME MANAGEMENT SYSTEM. ALLTEL shall provide
                  the Time Management System described in Section 4 of Exhibit A
                  and as compensation therefore, Client shall pay the following
                  Service Fees:

                                        3
<PAGE>

                  License Fee (includes the 706 man-hours of development
                  services described in Section 4.3 of Exhibit A)       $[*****]

                  Monthly Support(, July 1 through December 31, 2000    $[*****]
                  Monthly Support **, January 1, 2001 through July
                  31, 2005                                              $[*****]

                  *        Assumes that ALLTEL resources needed to provide
                           support will not exceed one (1) FTE.

                  **       Assumes that ALLTEL resources needed to provide
                           support will not exceed one-half (.5) FTE.

                  If the initial development of the Time Management System
                  requires in excess of 706-man-hours or the ALLTEL resources
                  required to perform the monthly support exceed the FTE
                  assumptions set forth above or if Client requests software
                  customizations or capacity in excess of that described in
                  Section 4 of Exhibit A, ALLTEL shall provide such additional
                  resources at the rates per hour set forth in Section 5.1 of
                  Exhibit E for Application Services and Development Variable
                  Staff. All related travel and materials shall be invoiced as a
                  Pass-Through Expense.

4.       The following new Section 8 shall be added to Exhibit M. to the
         Agreement:

         "8.      TRAINING ROOM PC DEPLOYMENT PROJECT. ALLTEL will install,
                  configure and test certain ALLTEL Software and ALLTEL-Provided
                  Third Party Software on Client's training personal computers
                  ("PCs") in the "Training Facilities" (as set forth below) as
                  described in this Section 8. ALLTEL will also provide
                  technical support for each Training Facility as described in
                  this Section 8. The testing to be performed is to verify that
                  each PC has connectivity to ALLTEL's training databases and
                  that the ALLTEL Software and ALLTEL-Provided Third Party
                  Software is properly configured. The Services described in
                  this section to be performed by ALLTEL shall be referred to as
                  the "Training Deployment Services".

                  8.1      ALLTEL RESPONSIBILITIES.

                           (a)      SOFTWARE. ALLTEL will install, configure and
                                    test the following ALLTEL Software, or
                                    ALLTEL Provided Third Party Software on
                                    Client PCs: ASAP, CCS, MIROR, CAMS, RVS,
                                    E91, TARP & Frontware, and CABS. ALLTEL will
                                    also load its training image which consists
                                    of NT 4.0 SP5, Glink v6.16, EDM v4.0,
                                    Hummingbird v6.2, and Oracle client v8.05.

                           (b)      FORMS. ALLTEL will develop the following
                                    forms:

                                        4
<PAGE>

                                    (i)      SOFTWARE COMPLETION FORM. ALLTEL
                                             will develop a Software Completion
                                             Form that will serve as a checklist
                                             of criteria to verify proper
                                             configuration and operation of the
                                             PCs for correct communications with
                                             the ALLTEL network for training.
                                             The content may include, but is not
                                             limited to the following:

                                             -    Workstation setup procedures;

                                             -    Workstations able to connect
                                                  to the server; and

                                             -    Workstation boot up process
                                                  with no error messages.

                                    (ii)     WEEKLY STATUS REPORTS. ALLTEL will
                                             prepare a weekly status report for
                                             Client's Project Manager describing
                                             work completed, work in progress,
                                             and any critical issues pertaining
                                             to the deployment project's
                                             completion.

                                    (iii)    FINAL STATUS REPORT. ALLTEL will
                                             provide a Final Status Report
                                             outlining ALLTEL's activities and
                                             describing the status of tasks
                                             associated with the deployment
                                             project. Significant
                                             accomplishments and problems will
                                             be identified. The Final Status
                                             Report may also include the
                                             following:

                                             -    All workstations communicating
                                                  to the ALLTEL network;

                                             -    Software application
                                                  deployment is operational;

                                             -    Detailed documentation
                                                  delivered;

                                             -    3270 access to IBM Host;

                                             -    Project change control
                                                  summary; and

                                             -    Problems, concerns, and
                                                  recommendations.

                           (c)      On-Site Support. An ALLTEL LAN/Desktop
                                    Support staff person will be on-site for
                                    each initial training class at each
                                    different Training Facility for two (2) Days
                                    of ALLTEL Software training. An ALLTEL
                                    LAN/Desktop Support staff person will be
                                    on-site for each subsequent class at each
                                    different Training Facility one (1)-day
                                    prior to the start of class and the first
                                    day of ALLTEL Software training.

         8.2      TRAINING FACILITIES. ALLTEL will provide the Training
                  Deployment Services at the following "Training Facilities".

                  -        Technology Training Center, 1400 Commerce Dr.,
                           Carlsbad, NM;

                  -        N New Mexico Community College, 1002 N. Onate St.
                           Espanola, NM;

                  -        Texarkana College, 2500 N Robinson Rd., Texarkana,
                           TX; Client Corporate headquarters in Irving, TX;

                                        5
<PAGE>

                  -        Tulsa Tech Center, 3638 S Memorial Dr., Tulsa, OK;

                  -        Broken Arrow Assignment Center, 2300 S. First Street,
                           Broken Arrow, OK;

                  -        Dallas, Texas (ALLTEL site), 4455 LBJ Fwy Suite 1100,
                           Dallas, TX; and

                  -        Woltcom - TBD.

         8.3      CLIENT RESPONSIBILITIES.

                  (a)      PC. Client will provide all PCs (including monitors)
                           as indicated:

                           -        Client HQ in Irving, HQ: 15 Compaq PIII
                                    450-500MHZ, 64MB Ram, CD-ROM, 10/100nic,
                                    17"monitor

                           -        Texarkana: 64 Compaq PIII 450-500MHz, 64MB
                                    Ram, CD-ROM, 10/100nic, 17"monitor

                           -        Carlsbad: 64 Generic PIII 450MHz, 64MB Ram,
                                    CD-ROM, 10/100 nic, 17"monitor

                           -        Espanola: 31 Gateway PIII 450MHz, 64MB Ram,
                                    CD-ROM, 10/100 nic, 17"monitor

                           -        Tulsa Tech Center: 16 HP Vectra PIII 450MHz,
                                    64MB Ram, CD-ROM, 10/100 nic, 17"monitor

                           -        Broken Arrow Assignment Center: 6 Compaq
                                    PIII 450-500 MHz, 64MB Ram, CD-ROM, 10/100
                                    nic, 17"monitor

                           -        Dallas (ALLTEL site):

                           -        Woltcom: To be mutually agreed by the
                                    parties.

                  (b)      All Category 5 patch cables are certified from WAN
                           termination, Router, Hub and to PC provided and
                           installed by the Client as indicated on project
                           schedule.

                  (c)      All ALLTEL Software and ALLTEL-Provided Third Party
                           Software loaded by ALLTEL will be removed from all
                           training room PCs and servers at the conclusion of
                           training. This will be carried out by Client
                           employees and not handled by contracting staff or
                           college staff.

                  (d)      Client will be [________] complete the removal of the
                           ALLTEL Software and ALLTEL-Provided Third Party
                           Software no later than three (3) Days after training
                           has concluded at each Training Facility. Within five
                           (5) Days of the completion of training, Client will
                           confirm in writing that ALLTEL Software and
                           ALLTEL-Provided Third Party Software has been removed
                           from the Training Facilities. The project
                           coordination for removing ALLTEL Software and
                           ALLTEL-Provided Third Party Software from training
                           sites will be coordinated by ALLTEL.

                                       6
<PAGE>

                  (e)      Client or Client's vendor will have the PCs shipped
                           and setup at each training site prior to the arrival
                           of ALLTEL staff as indicated by schedule.

         8.4      ASSUMPTIONS. The estimated fees and schedules for the Training
                  Deployment Services are based on the following assumptions:

                  (a)      ALLTEL is not responsible for infrastructure or PC
                           equipment and components that are not in place and
                           functioning prior to ALLTEL's commencement of the
                           Training Deployment Services.

                  (b)      All connectivity equipment will be installed and
                           setup in working order prior to the arrival of ALLTEL
                           resources as indicated on project schedule.

                  (c)      ALLTEL is not responsible for replacement training
                           PCs if the PCs break.

                  (d)      ALLTEL is not responsible for the original PC image
                           of the Training Facilities' PCs.

                  (e)      Adequate numbers of ports for training will be
                           configures for each classroom as describe din
                           training schedule.

                  (f)      Server shipped by CompuCom will be delivered to
                           appropriate site on time per schedule as follows:

<TABLE>
<S>                         <C>
Irving                       5/22/2000
Texarkana                    5/15/2000
Carlsbad                     5/10/2000
Espanola                     5/02/2000
Broken Arrow (Tulsa)         5/30/2000
Dallas (ALLTEL)              4/24/2000
</TABLE>

                           Woltcom server will be available to ALLTEL by 5/2/00.

                  (g)      Servers configured by CompuCom will be configured
                           correctly and in working order with Windows NT v4.0
                           with Service Pack 5.

                  (h)      A stand by server will be configured and available to
                           be shipped for next day delivery by Client or
                           Client's Vendor if there is a problem with a server.

                  (i)      ALLTEL staff has full administrative rights and
                           access to all Training Facility servers and PCs.

                  (j)      There will be only one training room setup task for
                           each Training Facility. There are no breakdown and
                           re-setup tasks to be performed by ALLTEL.

                                       7
<PAGE>

                  (k)      PC count includes on trainer for each class.

                  (l)      No printer requirements have been identified. The
                           Training Facility is responsible for any future
                           network printer needs.

                  (m)      There is a phone in each training room that provides
                           ALLTEL access during server and PC setup and
                           configuration.

                  (n)      Once the server and all PCs at a training sit are
                           configured and tested, on one will have the
                           authorization to install software or make any changes
                           without ALLTEL approval.

                  (o)      All changes to the project will be scheduled and
                           approved via the Change Management Request process.

                  (p)      If the training schedule changes after 4/27/00,
                           ALLTEL will reevaluate the number of hours required
                           to support the training effort."

5.       The following new Section 4.6 shall be added to Exhibit E to the
         Agreement:

         "4.6     TRAINING DEPLOYMENT SERVICES. ALLTEL will provide the Training
                  Deployment Services described in Section 8 of Exhibit M for
                  the following rates and charges:

                  Weekday (non-holiday), 8:00 a.m.-5:00 p.m.: $[*****] per man
                  hour for project management. Estimated project management man
                  hours are 600.

                  Weekday and Weekends (non-holiday), 8:00 a.m.-5:00 p.m.
                  schedule: $[*****] per hour for ALLTEL Technicians. Estimated
                  hours are 2,850.

                  In the event that any of the assumptions set forth in Section
                  8.4 of Exhibit M is materially incorrect or Client fails to
                  timely perform any of its responsibilities set forth in
                  Section 8.3 of Exhibit M, and ALLTEL's performance of the
                  Training Development Services is negatively impacted as a
                  result, ALLTEL reserves the right to adjust the project
                  schedule for the Training Development Services or increase the
                  rates charged by ALLTEL accordingly.

                  All travel and related expenditures will be invoiced to Client
                  as Pass-Through Expense."

6.       All capitalized terms not otherwise defined in this second Amendment
         shall have the same meaning set forth in the Agreement.

7.       Except as herein expressly amended, the Agreement as previously amended
         is ratified, confirmed and remains in full force and effect.

8.       All references to the Agreement shall mean as such Agreement is amended
         hereby and as may in the future be amended, restated, supplemented or
         modified from time to time.

                                        8
<PAGE>

9.       This Second Amendment may be executed by the parties hereto
         individually or in combination, in one or more counterparts, each of
         which shall be an original and all of which shall constitute one and
         the same agreement.

         IN WITNESS WHEREOF, the parties have executed this Second Amendment as
of the Second Amendment Effective Date by their duly authorized representatives.

ALLTEL INFORMATION SERVICES,               VALOR TELECOMMUNICATIONS ENTERPRISES,
INC.                                       LLC

By: /s/ Roger Leitner                      By:  /s/ Kenneth R. Cole
    _______________________________            _____________________________

Name: /s/ Roger Leitner                    Name:    Kenneth R. Cole
      _____________________________              ___________________________

Title:                                     Title: President & CEO
       ____________________________              ___________________________

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