<PAGE>
                                                                   Exhibit 10.11

                       MCI WORLDCOM NETWORK SERVICES, INC.

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.

                                 AMENDMENT NO. 6

         This Amendment No. 6 (the "AMENDMENT NO. 6") is made this 26th day of
March, 2003, by and between Valor Telecommunications Enterprises, L.L.C.
("CUSTOMER") and MCI WORLDCOM Network Services, Inc. ("MCI"), to those certain
Program Enrollment Terms (the "PET"), to that certain Telecommunications
Services Agreement more particularly described as TSA # VTE - 001019 (the
"TSA"), made by and between Customer and MCI dated September 30, 2000, including
all prior applicable amendments thereto (the "PRIOR AMENDMENTS"). In the event
of any conflict between the terms of the TSA, the PET, any Prior Amendment or
any applicable Attachment and the terms of this Amendment No. 6, the terms of
this Amendment No. 6 shall control. The TSA along with the PET, the Prior
Amendments, all applicable Attachment(s), and this Amendment No. 6 shall
collectively be referred to as the "AGREEMENT". Capitalized terms not defined
herein shall have the meaning ascribed to them in other documents referenced
herein. All references to "MCI WorldCom" in the Agreement including any
attachments, schedules or exhibits thereto, will be deemed to refer to "MCI".
This Amendment No. 6 does not constitute the assumption of the Agreement as that
term is used under applicable bankruptcy law.

         In consideration of good and valuable consideration, the receipt and
sufficiency of which are hereby acknowledged, the parties agree as follows:

1.       SERVICE TERM. The parties agree to substitute Section 1 of the PET to
         read in its entirety as follows:

         1.       SERVICE TERM. This Agreement shall commence as of October 19,
                  2000 (the "EFFECTIVE DATE"), and shall continue for a period
                  of thirty-six (36) months commencing with the first (1st) day
                  of the month following the date this Amendment No. 6 has been
                  fully executed by both parties and delivered to Customer (the
                  "SERVICE TERM"). Upon expiration of the Service Term, the
                  Switched Services in question will continue to be provided
                  pursuant to the same terms and conditions as are then in
                  effect (including without limitation, the applicable rates,
                  discounts and commitments, if any), subject to termination by
                  either party upon thirty (30) days prior written notice to the
                  other party.

2.       CUSTOMER'S MINIMUM REVENUE COMMITMENTS. Commencing with the first (1st)
         day of the month following the date this Amendment No. 6 has been fully
         executed by both parties and delivered to Customer, the parties agree
         to substitute Section 5 of the PET to read in its entirety as follows:

         5.       CUSTOMER'S MINIMUM REVENUE COMMITMENT:

                  (A)      Commencing with the first (1st) day of the month
                           following the date this Amendment No. 6 has been
                           fully executed by both parties and delivered to
                           Customer and continuing through the end of the
                           Service Term (including

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                           any extensions thereto) (the "COMMITMENT PERIOD"),
                           Customer agrees to maintain on a take-or-pay basis,
                           Monthly Revenue (as defined in Section 2 above) of at
                           least $[*****] ("CUSTOMER'S MINIMUM REVENUE
                           COMMITMENT").

                  (B)      Notwithstanding anything to the contrary contained in
                           this Agreement, as soon as Customers cumulative
                           Monthly Revenue from MCI under the terms of this
                           Agreement and commencing with the first (1st) day of
                           the Commitment Period (as described in Subsection
                           5(A) above) are equal to at least $[*****] in the
                           aggregate, Customer may elect to terminate Customer's
                           Minimum Revenue Commitment described in Subsection
                           5(A) above by providing MCI written notice ("CUSTOMER
                           NOTICE"). In such event, commencing with the first
                           day of the first full month following at least thirty
                           (30) days after MCI receives the Customer Notice,
                           Customers Minimum Revenue Commitment shall terminate
                           and will no longer be in force or effect.

3.       DEFICIENCY CHARGE. Commencing with the first (1st) day of the month
         following the date this Amendment No. 6 has been fully executed by both
         parties and delivered to Customer, the parties agree to substitute
         Section 6 of the PET to read in its entirety as follows:

         6.       DEFICIENCY CHARGE:

                  (A)      In the event Customer does not maintain Customer's
                           Minimum Revenue Commitment in any month during the
                           Commitment Period (regardless of whether Customer has
                           commenced using any or all of the Switched Services
                           described herein), then for those month(s) only,
                           Customer will pay MCI the difference between
                           Customer's Minimum Revenue Commitment and Customers
                           actual Monthly Revenue for such month ("DEFICIENCY
                           CHARGE"). The Deficiency Charge will be due at the
                           same time payment is due for Switched Services
                           provided to Customer for the billing period in which
                           the Deficiency Charge arises or immediately in an
                           amount equal to Customer's Minimum Revenue Commitment
                           for the unexpired portion of the Service Term if MCI
                           terminates this Agreement based on Customers default
                           or if Customer terminates this Agreement pursuant to
                           Subsection 2(A) of the TSA.

                  (B)      It is agreed that MCI's damages in the event Customer
                           fails to maintain Customer's Minimum Revenue
                           Commitment shall be difficult or impossible to
                           ascertain. The provision for a Deficiency Charge in
                           Subsection (A) is intended, therefore, to establish
                           liquidated damages in the event Customer fails to
                           maintain Customer's Minimum Revenue Commitment and is
                           not intended as a penalty.

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4.       SPECIAL RATES:

         (A)      Notwithstanding anything to the contrary contained in the
         Agreement or the Attachment (or CLASSIC SWITCHLESS/END USER DEDICATED
         Services; the Attachment for CLASSIC CARRIER TERMINATION Service
         (collectively, the "CLASSIC ATTACHMENTS"), commencing within ten (10)
         business days following the date this Amendment No. 6 has been fully
         executed by both parties and delivered to Customer, Customer's rates
         for the applicable CLASSIC Services will be the respective rates per
         minute set forth below. All other rates will be as set forth in the
         Agreement or the CLASSIC Attachments.

                  (i)      CLASSIC CARRIER TERMINATION Service and CLASSIC END
         USER DEDICATED 1+ Service - Customer's MEXICO rate for calls from the
         48 contiguous United States to Mexico will be the respective rates and
         locations per minute set forth below: [NOT SUBJECT TO DISCOUNT.]

<TABLE>
<CAPTION>
     LOCATION                      RATE
     --------                      ----
<S>                               <C>
MEXICO - MEXICO CITY              $[*****]
MEXICO - GUADALAJARA              $[*****]
MEXICO - MONTERREY                $[*****]
</TABLE>

                  (ii)     CLASSIC SWITCHLESS 1+ Service - Customers MEXICO rate
         for calls from the 48 contiguous United States to Mexico will be the
         respective rates and locations per minute set forth below: [NOT SUBJECT
         TO DISCOUNT.]

<TABLE>
<CAPTION>
   LOCATION                        RATE
   --------                        ----
<S>                               <C>
MEXICO - MEXICO CITY              $[*****]
MEXICO - GUADALAJARA              $[*****]
MEXICO - MONTERREY                $[*****]
</TABLE>

                  (iii)    CLASSIC SWITCHLESS 1+ Service and CLASSIC SWITCHLESS
         TOLL FREE Service - Customer's INTERSTATE rate for calls within the 48
         United States will be $0.0340 per minute. [NOT SUBJECT TO DISCOUNT.]

                  (iv)     CLASSIC SWITCHLESS 1+ Service and CLASSIC SWITCHLESS
         TOLL FREE Service - Customer's INTRASTATE rate for calls within the
         following states will be the respective rates per minute set forth
         below: [NOT SUBJECT TO DISCOUNT.]

<TABLE>
<CAPTION>
  STATE                                               RATE
  -----                                               ----
<S>                                                 <C>
 OKLAHOMA                                           $[*****]
TEXAS                                               $[*****]
NEW MEXICO                                          $[*****]
</TABLE>

         (B)      Notwithstanding anything to the contrary contained in the TSA,
         MCI reserves the right to modify the rates described in Subparts (i)
         and (ii) of Subsection (A) above (which

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         charge modifications shall not exceed then-current generally available
         MCI charges for comparable services), upon not less than seven (7)
         calendar days' prior notice to Customer (facsimile being acceptable),
         which notice will state the effective date for the charge modification.
         Further, MCI reserves the right to modify the rates described in
         Subparts (iii) and (iv) of Subsection (A) above (which charge
         modifications shall not exceed then-current generally available MCI
         charges for comparable services), upon not less than thirty (30)
         calendar days' prior notice to Customer (facsimile being acceptable),
         which notice will state the effective date for the charge modification.

5.       CUSTOMER CREDITS:

         (A)      In consideration for Customers Minimum Revenue Commitments and
         other good and valuable consideration, the receipt and sufficiency of
         which are hereby acknowledged, in then event Customer maintains Monthly
         Revenue (as defined in Section 2 of the PET) of at least the following
         amounts during each of the respective billing periods set forth below:

<TABLE>
<CAPTION>
BILLING PERIOD                                        MONTHLY REVENUE
-------------                                         ---------------
<S>                                                   <C>
October 2003                                             $[*****]
November 2003                                            $[*****]
December 2003                                            $[*****]
January 2004                                             $[*****]
</TABLE>

         MCI agrees to give Customer a one-time credit equal to $[*****] (the
         "FIRST SPECIAL CREDIT"). MCI shall apply the First Special Credit
         commencing with Customer's second invoice from MCI following the
         January 2004 billing period; provided, however, in no event will the
         amount of the First Special Credit exceed $[*****] nor will the First
         Special Credit to be applied exceed the amount of Customer's invoice
         (i.e., any excess amounts will be applied to Customers successive
         invoices from MCI).

         (B)      In further consideration of good and valuable consideration,
         the receipt and sufficiency of which are hereby acknowledged, in the
         event Customer's cumulative Monthly Revenue from MCI under the terms of
         this Agreement and commencing with the first (1st) day of the
         Commitment Period (as described in Subsection 5(A) of the PET) are
         equal to at least $[*****] in the aggregate (the "BURNOUT"), MCI
         agrees to give Customer a one-time credit equal to $[*****] (the
         "SECOND SPECIAL CREDIT"). The Second Special Credit, if any, will be
         applied to Customer's next invoice following Customer's obtainment of
         the Burnout; provided, however, in no event will the amount of the
         Second Special Credit exceed $[*****] nor will the Second --------
         Special Credit to be applied exceed the amount of Customer's invoice
         (i.e., any excess amounts will be applied to Customer's successive
         invoices from MCI).

6.       PRICING AND COMMITMENT REVIEW. Following execution of this Amendment
         No. 6, each party agrees (no more than once every six (6) months) to
         discuss in good faith the rates and commitments for Switched Services
         hereunder. Provided, however, nothing contained herein shall require
         MCI to agree to any rate or commitment

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         modification and further, changes to the rates or commitments for
         Switched Services hereunder must be mutually agreed to in writing by
         the parties and specifically reference this Agreement and the Switched
         Services described herein.

7.       OTHER TERMS AND CONDITIONS. Except as specifically amended or modified
         herein, the terms and conditions of the Agreement will remain in full
         force and effect throughout the Service Term and any extensions
         thereof.

         IN WITNESS WHEREOF, the parties have entered into this Amendment No. 6
on the date first written above.

VALOR TELECOMMUNICATIONS                MCI WORLDCOM NETWORK
ENTERPRISES, L.L.C.                     SERVICES, INC.

By: /s/ William M. Ojile, Sr.           By: /s/ Peter M. Cassidy
    ---------------------------------       ------------------------------------

        William M. Ojile, Sr.                       Peter M. Cassidy
    ---------------------------------       ------------------------------------
           (Print Name)                               (Print Name)

       Senior Vice President,
    General Counsel & Secretary            Vice President, Wholesale Services
    ---------------------------------      -------------------------------------
             (Title)                                    (Title)

               3/26/03                                  3/27/03
    ---------------------------------      -------------------------------------
               (Date)                                    (Date)

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